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  • 101.
    Eriksson, Jonas
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Grundström, Christin
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Sauer-Eriksson, A Elisabeth
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Sauer, Uwe H
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Wolf-Watz, Hans
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Elofsson, Mikael
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Small Molecule Screening for Inhibitors of the YopH Phosphatase of Yersinia pseudotuberculosis2012In: Advances in Yersinia Research, New York: Springer, 2012, Vol. 954, p. 357-363Chapter in book (Refereed)
    Abstract [en]

    Bacterial virulence systems are attractive targets for development of new antibacterial agents. Yersinia spp. utilize the type III secretion (T3S) system to secrete and translocate Yersinia outer proteins (Yop effectors) into the cytosol of the target cell and thereby overcome host defenses to successfully establish an infection. Thus, the Yop effectors constitute attractive targets for drug development. In the present study we apply small molecule screening to identify inhibitors of one of the secreted proteins YopH, a tyrosine phosphatase required for virulence. Characterization of seven inhibitors indicated that both competitive and noncompetitive inhibitors were identified with IC50 values of 6–20 μM.

  • 102.
    Erttmann, Saskia F.
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Gekara, Nelson O.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
    Hydrogen peroxide release by bacteria suppresses inflammasome-dependent innate immunity2019In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, article id 3493Article in journal (Refereed)
    Abstract [en]

    Hydrogen peroxide (H2O2) has a major function in host-microbial interactions. Although most studies have focused on the endogenous H2O2 produced by immune cells to kill microbes, bacteria can also produce H2O2. How microbial H2O2 influences the dynamics of host-microbial interactions is unclear. Here we show that H2O2 released by Streptococcus pneumoniae inhibits inflammasomes, key components of the innate immune system, contributing to the pathogen colonization of the host. We also show that the oral commensal H2O2-producing bacteria Streptococcus oralis can block inflammasome activation. This study uncovers an unexpected role of H2O2 in immune suppression and demonstrates how, through this mechanism, bacteria might restrain the immune system to co-exist with the host.

  • 103.
    Erttmann, Saskia F.
    et al.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Härtlova, Anetta
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Sloniecka, Marta
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Raffi, Faizal A. M.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Hosseinzadeh, Ava
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Edgren, Tomas
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Rofougaran, Reza
    Resch, Ulrike
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Fällman, Maria
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Ek, Torben
    Gekara, Nelson O.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Loss of the DNA Damage Repair Kinase ATM Impairs Inflammasome-Dependent Anti-Bacterial Innate Immunity2016In: Immunity, ISSN 1074-7613, E-ISSN 1097-4180, Vol. 45, no 1, p. 106-118Article in journal (Refereed)
    Abstract [en]

    The ATM kinase is a central component of the DNA damage repair machinery and redox balance. ATM dysfunction results in the multisystem disease ataxia-telangiectasia (AT). A major cause of mortality in AT is respiratory bacterial infections. Whether ATM deficiency causes innate immune defects that might contribute to bacterial infections is not known. Here we have shown that loss of ATM impairs inflammasome- dependent anti-bacterial innate immunity. Cells from AT patients or Atm(-/-) mice exhibited diminished interleukin-1 beta (IL-1 beta) production in response to bacteria. In vivo, Atm(-/-) mice were more susceptible to pulmonary S. pneumoniae infection in a manner consistent with inflammasome defects. Our data indicate that such defects were due to oxidative inhibition of inflammasome complex assembly. This study reveals an unanticipated function of reactive oxygen species (ROS) in negative regulation of inflammasomes and proposes a theory for the notable susceptibility of AT patients to pulmonary bacterial infection.

  • 104.
    Espaillat, Akbar
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Carrasco-Lopez, Cesar
    Bernardo-Garcia, Noelia
    Pietrosemoli, Natalia
    Otero, Lisandro H.
    Alvarez, Laura
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    de Pedro, Miguel A.
    Pazos, Florencio
    Davis, Brigid M.
    Waldor, Matthew K.
    Hermoso, Juan A.
    Cava, Felipe
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Structural basis for the broad specificity of a new family of amino-acid racemases2014In: Acta Crystallographica Section D: Biological Crystallography, ISSN 0907-4449, E-ISSN 1399-0047, Vol. 70, p. 79-90Article in journal (Refereed)
    Abstract [en]

    Broad-spectrum amino-acid racemases (Bsrs) enable bacteria to generate noncanonical D-amino acids, the roles of which in microbial physiology, including the modulation of cell-wall structure and the dissolution of biofilms, are just beginning to be appreciated. Here, extensive crystallographic, mutational, biochemical and bioinformatic studies were used to define the molecular features of the racemase BsrV that enable this enzyme to accommodate more diverse substrates than the related PLP-dependent alanine racemases. Conserved residues were identified that distinguish BsrV and a newly defined family of broad-spectrum racemases from alanine racemases, and these residues were found to be key mediators of the multispecificity of BrsV. Finally, the structural analysis of an additional Bsr that was identified in the bioinformatic analysis confirmed that the distinguishing features of BrsV are conserved among Bsr family members.

  • 105. Evans, Margery L.
    et al.
    Chorell, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Taylor, Jonathan D.
    Ådén, Jörgen
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Götheson, Anna
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Li, Fei
    Koch, Marion
    Sefer, Lea
    Matthews, Steve J.
    Wittung-Stafshede, Pernilla
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Almqvist, Fredrik
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Chapman, Matthew R.
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    The Bacterial Curli System Possesses a Potent and Selective Inhibitor of Amyloid Formation2015In: Molecular Cell, ISSN 1097-2765, E-ISSN 1097-4164, Vol. 57, no 3, p. 445-455Article in journal (Refereed)
    Abstract [en]

    Summary Curli are extracellular functional amyloids that are assembled by enteric bacteria during biofilm formation and host colonization. An efficient secretion system and chaperone network ensures that the major curli fiber subunit, CsgA, does not form intracellular amyloid aggregates. We discovered that the periplasmic protein CsgC was a highly effective inhibitor of CsgA amyloid formation. In the absence of CsgC, CsgA formed toxic intracellular aggregates. In vitro, CsgC inhibited CsgA amyloid formation at substoichiometric concentrations and maintained CsgA in a non-β-sheet-rich conformation. Interestingly, CsgC inhibited amyloid assembly of human α-synuclein, but not Aβ42, in vitro. We identified a common D-Q-Φ-X0,1-G-K-N-ζ-E motif in CsgC client proteins that is not found in Aβ42. CsgC is therefore both an efficient and selective amyloid inhibitor. Dedicated functional amyloid inhibitors may be a key feature that distinguishes functional amyloids from disease-associated amyloids.

  • 106.
    Fahlgren, Anna
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Avican, Kemal
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Westermark, Linda
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Nordfelth, Roland
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Fällman, Maria
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Colonization of cecum is important for development of persistent infection by Yersinia pseudotuberculosis2014In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 82, no 8, p. 3471-3482Article in journal (Refereed)
    Abstract [en]

    Yersiniosis is a human disease caused by the bacterium Yersinia pseudotuberculosis or Yersinia enterocolitica. The infection is usually resolved but can lead to postinfectious sequelae, including reactive arthritis and erythema nodosum. The commonly used Yersinia mouse infection model mimics acute infection in humans to some extent but leads to systemic infection and eventual death. Here, we analyzed sublethal infection doses of Y. pseudotuberculosis in mice in real time using bioluminescent imaging and found that infections using these lower doses result in extended periods of asymptomatic infections in a fraction of mice. In a search for the site for bacterial persistence, we found that the cecum was the primary colonization site and was the site where the organism resided during a 115-day infection period. Persistent infection was accompanied by sustained fecal shedding of cultivable bacteria. Cecal patches were identified as the primary site for cecal colonization during persistence. Y. pseudotuberculosis bacteria were present in inflammatory lesions, in localized foci, or as single cells and also in neutrophil exudates in the cecal lumen. The chronically colonized cecum may serve as a reservoir for dissemination of infection to extraintestinal sites, and a chronic inflammatory state may trigger the onset of postinfectious sequelae. This novel mouse model for bacterial persistence in cecum has potential as an investigative tool to unveil a deeper understanding of bacterial adaptation and host immune defense mechanisms during persistent infection.

  • 107.
    Fahlgren, Anna
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Westermark, Linda
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Akopyan, Karen
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Fällman, Maria
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Cell type-specific effects of Yersinia pseudotuberculosis virulence effectors2009In: Cellular Microbiology, ISSN 1462-5814, E-ISSN 1462-5822, Vol. 11, no 12, p. 1750-1767Article in journal (Refereed)
    Abstract [en]

    One important feature of Yersinia pseudotuberculosis that enables resistance against the host immune defence is delivery of the antiphagocytic effectors YopH and YopE into phagocytic cells. The tyrosine phosphatase YopH influences integrin signalling, and YopE impairs cytoskeletal dynamics by inactivating Rho GTPases. Here, we report the impact of these effectors on internalization by dendritic cells (DCs), which internalize antigens to orchestrate host immune responses. We found that this pathogen resists internalization by DCs via YopE. YopH that is important for blocking phagocytosis by macrophages and neutrophils and which is also present inside the DCs does not contribute to the resistance. However, the YopH targets Fyb and p130Cas show higher expression levels in macrophages than in DCs. Furthermore, live cell microscopy revealed that the cells internalize Y. pseudotuberculosis in different ways: the macrophages utilize a locally restricted receptor-mediated zipper mechanism, whereas DCs utilize macropinocytosis involving constitutive ruffling that randomly catches bacteria into membrane folds. We conclude that YopH impacts early phagocytic signalling from the integrin receptor to which the bacterium binds and that this tight receptor-mediated stimulation is absent in DC macropinocytosis. Inactivation of cytoskeletal dynamics by YopE affects ruffling activity and hence also internalization. The different modes of internalization can be coupled to the major functions of these respective cell types: elimination by phagocytosis and antigen sampling.

  • 108.
    Farag, Salah
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Francis, Monika K.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Nadeem, Aftab
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Wai, Sun Nyunt
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Francis, Matthew S
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Impact of Defective Translocon Assemblies on Hierarchal Yop Effector Translocation by Yersinia pseudotuberculosisManuscript (preprint) (Other academic)
  • 109. Fasullo, Michael
    et al.
    Tsaponina, Olga
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Sun, Mingzeng
    Chabes, Andrei
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Elevated dNTP levels suppress hyper-recombination in Saccharomyces cerevisiae S-phase checkpoint mutants2010In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 38, no 4, p. 1195-1203Article in journal (Refereed)
    Abstract [en]

    MEC1, the essential yeast homolog of the human ATR/ATM genes, controls the S-phase checkpoint and prevents replication fork collapse at slow zones of DNA replication. The viability of hypomorphic mec1-21 is reduced in the rad52 mutant, defective in homologous recombination, suggesting that replication generates recombinogenic lesions. We previously observed a 6-, 10- and 30-fold higher rate of spontaneous sister chromatid exchange (SCE), heteroallelic recombination and translocations, respectively, in mec1-21 mutants compared to wild-type. Here we report that the hyper-recombination phenotype correlates with lower deoxyribonucleoside triphosphate (dNTP) levels, compared to wild-type. By introducing a dun1 mutation, thus eliminating inducible expression of ribonucleotide reductase in mec1-21, rates of spontaneous SCE increased 15-fold above wild-type. All the hyper-recombination phenotypes were reduced by SML1 deletions, which increase dNTP levels. Measurements of dNTP pools indicated that, compared to wild-type, there was a significant decrease in dNTP levels in mec1-21, dun1 and mec1-21 dun1, while the dNTP levels of mec1-21 sml1, mec1-21 dun1 sml1 and sml1 mutants were approximately 2-fold higher. Interestingly, higher dNTP levels in mec1-21 dun1 sml1 correlate with approximately 2-fold higher rate of spontaneous mutagenesis, compared to mec1-21 dun1. We suggest that higher dNTP levels in specific checkpoint mutants suppress the formation of recombinogenic lesions.

  • 110. Fernebro, Jenny
    et al.
    Blomberg, Christel
    Morfeldt, Eva
    Wolf-Watz, Hans
    Umeå University, Faculty of Science and Technology, Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Normark, Staffan
    Normark, Birgitta Henriques
    The influence of in vitro fitness defects on pneumococcal ability to colonize and to cause invasive disease.2008In: BMC microbiology, ISSN 1471-2180, Vol. 8, p. 65-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Streptococcus pneumoniae is a genetically diverse major human pathogen, yet a common colonizer of the nasopharynx. Here we analyzed the influence of defects affecting in vitro growth rate, on the ability of S. pneumoniae to colonize and to cause invasive disease in vivo. RESULTS: Of eleven different clinical isolates one serotype 14 carrier isolate showed a significantly longer generation time as compared to other isolates, and was severely attenuated in mice. To directly investigate the impact of growth rate on virulence, a panel of mutants in five non-essential housekeeping genes was constructed in the virulent TIGR4 background by insertion-deletion mutagenesis. Three of these mutants (ychF, hemK and yebC) were, to different degrees, growth defective, and showed a reduced invasiveness in an intranasal murine challenge model that correlated to their in vitro growth rate, but remained capable of colonizing the upper airways. The growth defect, as well as virulence defect of the hemK insertion-deletion mutant, was mediated by polarity effects on the downstream yrdC gene, encoding a probable chaperone in ribosome assembly. CONCLUSION: We conclude that large fitness defects are needed to completely prevent pneumococci from causing invasive disease after intranasal challenge. However, even severe growth defects still allow pneumococci to persistently colonize the upper airways.

  • 111. Flentie, Kelly
    et al.
    Harrison, Gregory A.
    Tükenmez, Hasan
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Livny, Jonathan
    Good, James A. D.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Sarkar, Souvik
    Zhu, Dennis X.
    Kinsella, Rachel L.
    Weiss, Leslie A.
    Solomon, Samantha D.
    Schene, Miranda E.
    Hansen, Mette R.
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Cairns, Andrew G.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Kulén, Martina
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Wixe, Torbjörn
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Lindgren, Anders E. G.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Chorell, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.
    Bengtsson, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Krishnan, K. Syam
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hultgren, Scott J.
    Larsson, Christer
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Stallings, Christina L.
    Chemical disarming of isoniazid resistance in Mycobacterium tuberculosis2019In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 116, no 21, p. 10510-10517Article in journal (Refereed)
    Abstract [en]

    Mycobacterium tuberculosis (Mtb) killed more people in 2017 than any other single infectious agent. This dangerous pathogen is able to withstand stresses imposed by the immune system and tolerate exposure to antibiotics, resulting in persistent infection. The global tuberculosis (TB) epidemic has been exacerbated by the emergence of mutant strains of Mtb that are resistant to frontline antibiotics. Thus, both phenotypic drug tolerance and genetic drug resistance are major obstacles to successful TB therapy. Using a chemical approach to identify compounds that block stress and drug tolerance, as opposed to traditional screens for compounds that kill Mtb, we identified a small molecule, C10, that blocks tolerance to oxidative stress, acid stress, and the frontline antibiotic isoniazid (INH). In addition, we found that C10 prevents the selection for INH-resistant mutants and restores INH sensitivity in otherwise INH-resistant Mtb strains harboring mutations in the katG gene, which encodes the enzyme that converts the prodrug INH to its active form. Through mechanistic studies, we discovered that C10 inhibits Mtb respiration, revealing a link between respiration homeostasis and INH sensitivity. Therefore, by using C10 to dissect Mtb persistence, we discovered that INH resistance is not absolute and can be reversed.

  • 112. Fleurie, Aurore
    et al.
    Zoued, Abdelrahim
    Alvarez, Laura
    Hines, Kelly M.
    Cava, Felipe
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Xu, Libin
    Davis, Brigid M.
    Waldor, Matthew K.
    A Vibrio cholerae BolA-Like Protein Is Required for Proper Cell Shape and Cell Envelope Integrity2019In: mBio, ISSN 2161-2129, E-ISSN 2150-7511, Vol. 10, no 4, article id e00790-19Article in journal (Refereed)
    Abstract [en]

    BolA family proteins are conserved in Gram-negative bacteria and many eukaryotes. While diverse cellular phenotypes have been linked to this protein family, the molecular pathways through which these proteins mediate their effects are not well described. Here, we investigated the roles of BolA family proteins in Vibrio cholerae, the cholera pathogen. Like Escherichia coli, V. cholerae encodes two BolA proteins, BolA and IbaG. However, in marked contrast to E. coli, where bolA is linked to cell shape and ibaG is not, in V. cholerae, bolA mutants lack morphological defects, whereas ibaG proved critical for the generation and/or maintenance of the pathogen's morphology. Notably, the bizarre-shaped, multipolar, elongated, and wide cells that predominated in exponential-phase Delta ibaG V. cholerae cultures were not observed in stationary-phase cultures. The V. cholerae Delta ibaG mutant exhibited increased sensitivity to cell envelope stressors, including cell wall-acting antibiotics and bile, and was defective in intestinal colonization. Delta ibaG V. cholerae had reduced peptidoglycan and lipid II and altered outer membrane lipids, likely contributing to the mutant's morphological defects and sensitivity to envelope stressors. Transposon insertion sequencing analysis of ibaG's genetic interactions suggested that ibaG is involved in several processes involved in the generation and homeostasis of the cell envelope. Furthermore, copurification studies revealed that IbaG interacts with proteins containing iron-sulfur clusters or involved in their assembly. Collectively, our findings suggest that V. cholerae IbaG controls cell morphology and cell envelope integrity through its role in biogenesis or trafficking of iron-sulfur cluster proteins. IMPORTANCE BolA-like proteins are conserved across prokaryotes and eukaryotes. These proteins have been linked to a variety of phenotypes, but the pathways and mechanisms through which they act have not been extensively characterized. Here, we unraveled the role of the BolA-like protein IbaG in the cholera pathogen Vibrio cholerae. The absence of IbaG was associated with dramatic changes in cell morphology, sensitivity to envelope stressors, and intestinal colonization defects. IbaG was found to be required for biogenesis of several components of the V. cholerae cell envelope and to interact with numerous iron-sulfur cluster-containing proteins and factors involved in their assembly. Thus, our findings suggest that IbaG governs V. cholerae cell shape and cell envelope homeostasis through its effects on iron-sulfur proteins and associated pathways. The diversity of processes involving ironsulfur-containing proteins is likely a factor underlying the range of phenotypes associated with BolA family proteins.

  • 113. Floyd, Kyle A.
    et al.
    Moore, Jessica L.
    Eberly, Allison R.
    Good, James A. D.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Shaffer, Carrie L.
    Zaver, Himesh
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Skaar, Eric P.
    Caprioli, Richard M.
    Hadjifrangiskou, Maria
    Adhesive Fiber Stratification in Uropathogenic Escherichia coli Biofilms Unveils Oxygen-Mediated Control of Type 1 Pili2015In: PLoS Pathogens, ISSN 1553-7366, E-ISSN 1553-7374, Vol. 11, no 3, article id e1004697Article in journal (Refereed)
    Abstract [en]

    Bacterial biofilms account for a significant number of hospital-acquired infections and complicate treatment options, because bacteria within biofilms are generally more tolerant to antibiotic treatment. This resilience is attributed to transient bacterial subpopulations that arise in response to variations in the microenvironment surrounding the biofilm. Here, we probed the spatial proteome of surface-associated single-species biofilms formed by uropathogenic Escherichia coli (UPEC), the major causative agent of community-acquired and catheter-associated urinary tract infections. We used matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) imaging mass spectrometry (IMS) to analyze the spatial proteome of intact biofilms in situ. MALDI-TOF IMS revealed protein species exhibiting distinct localizations within surface-associated UPEC biofilms, including two adhesive fibers critical for UPEC biofilm formation and virulence: type 1 pili (Fim) localized exclusively to the air-exposed region, while curli amyloid fibers localized to the air-liquid interface. Comparison of cells grown aerobically, fermentatively, or utilizing an alternative terminal electron acceptor showed that the phase-variable fim promoter switched to the "FF" orientation under oxygen-deplete conditions, leading to marked reduction of type 1 pili on the bacterial cell surface. Conversely, S pili whose expression is inversely related to fim expression were upregulated under anoxic conditions. Tethering the fim promoter in the "ON" orientation in anaerobically grown cells only restored type 1 pili production in the presence of an alternative terminal electron acceptor beyond oxygen. Together these data support the presence of at least two regulatory mechanisms controlling fim expression in response to oxygen availability and may contribute to the stratification of extracellular matrix components within the biofilm. MALDI IMS facilitated the discovery of these mechanisms, and we have demonstrated that this technology can be used to interrogate subpopulations within bacterial biofilms.

  • 114.
    Fonfara, Ines
    et al.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Helmholtz Centre for Infection Research, Department of Regulation in Infection Biology, Braunschweig, Germany.
    Le Rhun, Anaïs
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Helmholtz Centre for Infection Research, Department of Regulation in Infection Biology, Braunschweig, Germany.
    Chylinski, Krzysztof
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Deptartment of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Austria.
    Makarova, Kira S.
    Lécrivain, Anne-Laure
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Bzdrenga, Janek
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Koonin, Eugene V.
    Charpentier, Emmanuelle
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Helmholtz Centre for Infection Research, Department of Regulation in Infection Biology, Braunschweig, Germany ; Hannover Medical School, Hannover, Germany .
    Phylogeny of Cas9 determines functional exchangeability of dual-RNA and Cas9 among orthologous type II CRISPR-Cas systems2014In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 42, no 4, p. 2577-2590Article in journal (Refereed)
    Abstract [en]

    The CRISPR-Cas-derived RNA-guided Cas9 endonuclease is the key element of an emerging promising technology for genome engineering in a broad range of cells and organisms. The DNA-targeting mechanism of the type II CRISPR-Cas system involves maturation of tracrRNA: crRNA duplex (dual-RNA), which directs Cas9 to cleave invading DNA in a sequence-specific manner, dependent on the presence of a Protospacer Adjacent Motif (PAM) on the target. We show that evolution of dual-RNA and Cas9 in bacteria produced remarkable sequence diversity. We selected eight representatives of phylogenetically defined type II CRISPR-Cas groups to analyze possible coevolution of Cas9 and dual-RNA. We demonstrate that these two components are interchangeable only between closely related type II systems when the PAM sequence is adjusted to the investigated Cas9 protein. Comparison of the taxonomy of bacterial species that harbor type II CRISPR-Cas systems with the Cas9 phylogeny corroborates horizontal transfer of the CRISPR-Cas loci. The reported collection of dual-RNA: Cas9 with associated PAMs expands the possibilities for multiplex genome editing and could provide means to improve the specificity of the RNA-programmable Cas9 tool.

  • 115.
    Forslund, Anna-Lena
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Forsberg, Åke
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Kuoppa, Kerstin
    FOI Swedish Defence Research Agency, Division of CBRN Defence and Security.
    Meibom, Karin L.
    Université Paris Descartes, Faculté de Médecine Necker-Enfants Malades; INSERM, U570, Unit of Pathogenesis of Systemic Infections.
    Alkhuder, Khaled
    Université Paris Descartes, Faculté de Médecine Necker-Enfants Malades; INSERM, U570, Unit of Pathogenesis of Systemic Infections.
    Dubail, Iharilalao
    Université Paris Descartes, Faculté de Médecine Necker-Enfants Malades; INSERM, U570, Unit of Pathogenesis of Systemic Infections.
    Dupuis, Marion
    Université Paris Descartes, Faculté de Médecine Necker-Enfants Malades; INSERM, U570, Unit of Pathogenesis of Systemic Infections.
    Charbit, Alain
    Université Paris Descartes, Faculté de Médecine Necker-Enfants Malades; INSERM, U570, Unit of Pathogenesis of Systemic Infections.
    Hfq, a novel pleiotropic regulator of virulence-associated genes in Francisella tularensis2009In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 77, no 5, p. 1866-80Article in journal (Refereed)
    Abstract [en]

    Francisella tularensis is a highly infectious pathogen that infects animals and humans, causing tularemia. The ability to replicate within macrophages is central for virulence and relies on expression of genes located in the Francisella pathogenicity island (FPI), as well as expression of other genes. Regulation of FPI-encoded virulence gene expression in F. tularensis involves at least four regulatory proteins and is not fully understood. Here we studied the RNA-binding protein Hfq in F. tularensis and particularly the role that it plays as a global regulator of gene expression in stress tolerance and pathogenesis. We demonstrate that Hfq promotes resistance to several cellular stresses (including osmotic and membrane stresses). Furthermore, we show that Hfq is important for the ability of the F. tularensis vaccine strain LVS to induce disease and persist in organs of infected mice. We also demonstrate that Hfq is important for stress tolerance and full virulence in a virulent clinical isolate of F. tularensis, FSC200. Finally, microarray analyses revealed that Hfq regulates expression of numerous genes, including genes located in the FPI. Strikingly, Hfq negatively regulates only one of two divergently expressed putative operons in the FPI, in contrast to the other known regulators, which regulate the entire FPI. Hfq thus appears to be a new pleiotropic regulator of virulence in F. tularensis, acting mostly as a repressor, in contrast to the other regulators identified so far. Moreover, the results obtained suggest a novel regulatory mechanism for a subset of FPI genes.

  • 116.
    Forslund, Anna-Lena
    et al.
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Salomonsson, Emelie Näslund
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Golovliov, Igor
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Kuoppa, Kerstin
    Michell, Stephen
    Titball, Richard
    Oyston, Petra
    Noppa, Laila
    FOI.
    Sjöstedt, Anders
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Forsberg, Åke
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    The type IV pilin, PilA, is required for full virulence of Francisella tularensis subspecies tularensis2010In: BMC Microbiology, ISSN 1471-2180, E-ISSN 1471-2180, Vol. 10, p. 227-Article in journal (Refereed)
    Abstract [en]

    This suggests that expression and surface localisation of PilA contribute to virulence in the highly virulent type A strain, while PilT was dispensable for virulence in the mouse infection model.

  • 117.
    Francis, Matthew
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Secretion systems and metabolism in the pathogenic Yersiniae2011In: Stress response in pathogenic bacteria / [ed] Stephen P. Kidd, United Kingdom: CAB International , 2011, 1, p. 185-220Chapter in book (Refereed)
    Abstract [en]

    The genus Yersinia comprises 11 species, three of which have clear etiology for causing human disease (Y. pestis, Y. pseudotuberculosis and Y. enterocolitica). The obligate pathogen Y. pestis is the most infamous of these being the causal agent of plague, a bivalent disease that when left untreated is invariably fatal. The lifecycle of Y. pestis is complex, being dependent on two diverse hosts – the invertebrate flea Xenopsylla cheopis and a mammalian host (usually wild rodents). Although capable of catastrophic consequences, plague in humans is accidental – a consequence of being infected with Y. pestis via the bite of an infected flea that has been forced from its normal rodent host. In brief, the initial stage of disease presents as swollen lymph nodes (buboes) and is termed bubonic plague, whereas the second stage is a more vigorous systemic infection that results in bacterial colonization of multiple tissue organs including the lung. This form of disease is termed pneumonic plague; a highly contagious disease that enables bacteria to rapidly and effectively spread to new hosts via aerosol droplets. In light of this, global health organizations routinely list Y. pestis as a category A biowarfare agent. On the other hand, Y. pseudotuberculosis and Y. enterocolitica are essentially environmental bacteria that are capable of causing spasmodic enteric disease (known as yersiniosis) outbreaks linked to the ingestion of contaminated food or fluids. While these diseases cause gastrointestinal discomfort, they are usually self-limiting and rarely associated with systemic disease. In certain susceptible individuals however, chronic reactive arthritic sequelae can be attributed to these bacteria.

    On account of their ability to cause human disease, a prolific amount of information is available that describes these three human pathogens with respect to their ecology, epidemiology and the pathogenesis of disease. In contrast, very little information is available concerning the additional Yersinia species (Y. frederiksenii, Y. intermedia, Y. kristensenii, Y. bercovieri, Y. mollaretii, Y. rohdei, Y. ruckeri, Y. aleksiciae, Y. mexicana and Y. aldovae). However, they might still be clinically relevant given their propensity to harbour a moderate number of genes that encode for products known to be associated with pathogenicity by other non-Yersinia bacteria. It is at least well established that Y. ruckeri is the causative agent of yersiniosis in infected salmonid fish, although the pathogenic mechanisms are comparatively poorly understood.

    In the first part of this chapter, the presence of known and suggested protein secretion mechanisms in the Yersiniae are described. Where appropriate, these individual processes are briefly discussed in the context of their contribution to bacterial pathogenesis to help the reader gain an understanding of their physiological importance within the various unique environments of an infected host. As considerably more is known about the pathogenic mechanisms of human pathogenic Yersinia, these examples will dominate the discussion. Then, focus will turn to the consequences of adaptation of pathogenic Yersinia to their surrounding environment. Where possible, emphasis will be given to the crosstalk between metabolism and the temporal and spatial regulatory control of these important secretion systems. This connection ensures that Yersinia conserve their valuable energy reserves to maximize their survival in stressful environments and only synthesize energetically expensive virulence determinants, such as multi-component secretion systems, when they will have utmost benefit during host infections.

  • 118.
    Francis, Matthew
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    The pathogenic Yersiniae: advances in the understanding of physiology and virulence2013In: Frontiers in Cellular and Infection Microbiology, ISSN 2235-2988, Vol. 3, no 51, p. 2p. 1-2Article, review/survey (Refereed)
  • 119.
    Francis, Matthew
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Aili, Margareta
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Wiklund, Magda-Lena
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Wolf-Watz, Hans
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    A study of the YopD-LcrH interaction from Yersinia pseudotuberculosis reveals a role for hydrophobic residues within the amphipathic domain of YopD2000In: Molecular Microbiology, ISSN 0950-382X, E-ISSN 1365-2958, Vol. 38, no 1, p. 85-102Article in journal (Refereed)
    Abstract [en]

    The enteropathogen Yersinia pseudotuberculosis is a model system used to study the molecular mechanisms by which Gram-negative pathogens translocate effector proteins into target eukaryotic cells by a common type III secretion machine. Of the numerous proteins produced by Y. pseudotuberculosis that act in concert to establish an infection, YopD (Yersiniaouter protein D) is a crucial component essential for yop regulation and Yop effector translocation. In this study, we describe the mechanisms by which YopD functions to control these processes. With the aid of the yeast two-hybrid system, we investigated the interaction between YopD and the cognate chaperone LcrH. We confirmed that non-secreted LcrH is necessary for YopD stabilization before secretion, presumably by forming a complex with YopD in the bacterial cytoplasm. At least in yeast, this complex depends upon the N-terminal domain and a C-terminal amphipathic α-helical domain of YopD. Introduction of amino acid substitutions within the hydrophobic side of the amphipathic α-helix abolished the YopD–LcrH interaction, indicating that hydrophobic, as opposed to electrostatic, forces of attraction are important for this process. Suppressor mutations isolated within LcrH could compensate for defects in the amphipathic domain of YopD to restore binding. Isolation of LcrH mutants unable to interact with wild-type YopD revealed no single domain responsible for YopD binding. The YopD and LcrH mutants generated in this study will be relevant tools for understanding YopD function during a Yersinia infection.

  • 120.
    Francis, Matthew S
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Type III secretion chaperones: a molecular toolkit for all occasions2010In: Handbook of molecular chaperones: roles, structures and mechanisms / [ed] Piero Durante and Leandro Colucci, New York: Nova Science Publishers , 2010, 1, p. 79-148Chapter in book (Refereed)
    Abstract [en]

    Common to many bacteria is the ability to establish a symbiotic relationship or to evade innate immune responses of an animal, plant, fish or insect host. Most often this capacity is mediated by a type III secretion system (T3SS). The function of these complex molecular machines is likened to a syringe-needle injection device that is dedicated to the translocation of effector proteins directly into target eukaryotic cells. Each translocated effector tends to possess a distinct enzymatic activity that aids in subverting host cell signaling for the benefit of the bacterium. Their translocation requires another class of secreted protein – the translocator – which form pores in the target eukaryotic cell plasma membrane through which the effectors may transit to gain entry into the cell interior. Most often, each secreted substrate requires a dedicated small, non-secreted cytoplasmic chaperone for their efficient secretion. Unlike traditional molecular chaperones, these specialized type III chaperones do not assist in protein folding and are not energized by ATP. Controversy still surrounds their primary role; as bodyguards to prevent premature aggregation or as pilots to direct substrate secretion through the correct T3SS. The later is supported by recent evidence that these chaperones can dock directly to the cytoplasmic face of the T3S machinery, possibly serving as a recognition motif for substrate secretion. Added to this functional complexity is their important contribution to system regulation, which can ultimately confer temporal order to substrate secretion. Moreover, some chaperones display a bewildering propensity to interact with several additional T3S-associated proteins – the relevance of which remains uncertain. Structural data has now appeared for several important type III chaperones, either alone or in complex with their cognate substrate. This is proving a fillip in our attempts to understand the mercurial ways in which these versatile proteins operate in nature. It is hoped that this article will provide information on type III chaperone function, as well as highlighting key recent advances in the field. May it also be a testament to the value of continued intense effort in unravelling the mysteries of type III chaperone biology.

  • 121.
    Francis, Matthew S.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Aili, Margareta
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Wiklund, Magda-Lena
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Wolf-Watz, Hans
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    A study of the YopD-LcrH interaction from Yersinia pseudotuberculosis reveals a role for hydrophobic residues within the amphipathic domain of YopD2000In: Molecular Microbiology, ISSN 0950-382X, E-ISSN 1365-2958, Vol. 38, no 1, p. 85-102Article in journal (Refereed)
    Abstract [en]

    The enteropathogen Yersinia pseudotuberculosis is a model system used to study the molecular mechanisms by which Gram-negative pathogens translocate effector proteins into target eukaryotic cells by a common type III secretion machine. Of the numerous proteins produced by Y. pseudotuberculosis that act in concert to establish an infection, YopD (Yersinia outer protein D) is a crucial component essential for yop regulation and Yop effector translocation. In this study, we describe the mechanisms by which YopD functions to control these processes. With the aid of the yeast two-hybrid system, we investigated the interaction between YopD and the cognate chaperone LcrH. We confirmed that non-secreted LcrH is necessary for YopD stabilization before secretion, presumably by forming a complex with YopD in the bacterial cytoplasm. At least in yeast, this complex depends upon the N-terminal domain and a C-terminal amphipathic alpha-helical domain of YopD. Introduction of amino acid substitutions within the hydrophobic side of the amphipathic alpha-helix abolished the YopD-LcrH interaction, indicating that hydrophobic, as opposed to electrostatic, forces of attraction are important for this process. Suppressor mutations isolated within LcrH could compensate for defects in the amphipathic domain of YopD to restore binding. Isolation of LcrH mutants unable to interact with wild-type YopD revealed no single domain responsible for YopD binding. The YopD and LcrH mutants generated in this study will be relevant tools for understanding YopD function during a Yersinia infection.

  • 122.
    Francis, Matthew S
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Amer, Ayad A A
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Helmholtz Centre for Infection Research, Braunschweig, Germany.
    Milton, Debra
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Department of Biological and Environmental Sciences, Troy University, Troy, AL, USA.
    Costa, Tiago R D
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Institute of Structural and Molecular Biology, University College London and Birkbeck, London, UK.
    Site-directed mutagenesis and its application in studying the interactions of T3S components2017In: Type 3 secretion systems: methods and protocols / [ed] Matthew L. Nilles and Danielle L. Jessen Condry, Humana Press, 2017, p. 11-31Chapter in book (Refereed)
    Abstract [en]

    Type III secretion systems are a prolific virulence determinant among Gram-negative bacteria. They are used to paralyze the host cell, which enables bacterial pathogens to establish often fatal infections—unless an effective therapeutic intervention is available. However, as a result of a catastrophic rise in infectious bacteria resistant to conventional antibiotics, these bacteria are again a leading cause of worldwide mortality. Hence, this report describes a pDM4-based site-directed mutagenesis strategy that is assisting in our foremost objective to better understand the fundamental workings of the T3SS, using Yersinia as a model pathogenic bacterium. Examples are given that clearly document how pDM4-mediated site-directed mutagenesis has been used to establish clean point mutations and in-frame deletion mutations that have been instrumental in identifying and understanding the molecular interactions between components of the Yersinia type III secretion system.

  • 123.
    Francis, Matthew S
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Auerbuch, Victoria
    Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, CA, United States.
    Editorial: The Pathogenic Yersiniae–Advances in the Understanding of Physiology and Virulence, Second Edition2019In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 9, p. 1-5, article id 119Article in journal (Refereed)
    Abstract [en]

    Of the 18 known Yersinia species, Y. pestis, Y. pseudotuberculosis, and Y. enterocolitica are pathogenic to humans and animals and are widely characterized. The zoonotic obligate pathogen Y. pestis is the causal agent of plague, a systemic disease that is usually fatal if left untreated (Zietz and Dunkelberg, 2004; Zhou et al., 2006). Free-living Y. enterocolitica and Y. pseudotuberculosis are the agents of yersiniosis, a rarely systemic gastrointestinal disease (Galindo et al., 2011). The remaining species are mostly harmless to humans, although Y. ruckeri is an enteric fish pathogen affecting mainly salmonids, while a few others display toxicity toward insects (Sulakvelidze, 2000; Tobback et al., 2007; Fuchs et al., 2008; Chen et al., 2010). At the forefront of Yersinia research are studies of classical microbiology, pathogenesis, protein secretion, niche adaptation, and regulation of gene expression. In pursuit of these endeavors, new frontiers are being forged on waves of methodological and technological innovation. In this second edition of the special research topic on the pathogenic Yersiniae is a compilation of reviews and research articles that summarize current knowledge and future research directions in the Yersinia pathophysiology field.

  • 124.
    Francis, Matthew S
    et al.
    Umeå University, Faculty of Science and Technology, Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Schesser, Kurt
    Forsberg, Åke
    Umeå University, Faculty of Science and Technology, Molecular Biology (Faculty of Science and Technology).
    Wolf-Watz, Hans
    Umeå University, Faculty of Science and Technology, Molecular Biology (Faculty of Science and Technology).
    Type III secretion systems in animal- and plant-interacting bacteria2004In: Cellular Microbiology, ASM Press, Washington, D.C. , 2004, p. 362-392Chapter in book (Other (popular science, discussion, etc.))
  • 125.
    Francis, Matthew
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Schesser, Kurt
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Forsberg, Åke
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Wolf-Watz, Hans
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Type III secretion systems in animal- and plant-interacting bacteria2000In: Cellular Microbiology, Washington, DC: ASM Press , 2000, 1, p. 239-263Chapter in book (Refereed)
  • 126. Fuhrmann, Jakob
    et al.
    Schmidt, Andreas
    Spiess, Silvia
    Lehner, Anita
    Turgay, Kürsad
    Mechtler, Karl
    Charpentier, Emmanuelle
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Clausen, Tim
    McsB is a protein arginine kinase that phosphorylates and inhibits the heat-shock regulator CtsR2009In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 324, no 5932, p. 1323-1327Article in journal (Refereed)
    Abstract [en]

    All living organisms face a variety of environmental stresses that cause the misfolding and aggregation of proteins. To eliminate damaged proteins, cells developed highly efficient stress response and protein quality control systems. We performed a biochemical and structural analysis of the bacterial CtsR/McsB stress response. The crystal structure of the CtsR repressor, in complex with DNA, pinpointed key residues important for high-affinity binding to the promoter regions of heat-shock genes. Moreover, biochemical characterization of McsB revealed that McsB specifically phosphorylates arginine residues in the DNA binding domain of CtsR, thereby impairing its function as a repressor of stress response genes. Identification of the CtsR/McsB arginine phospho-switch expands the repertoire of possible protein modifications involved in prokaryotic and eukaryotic transcriptional regulation.

  • 127.
    Fällman, Erik
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schedin, Staffan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Jass, Jana
    Andersson, Magnus
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Uhlin, Bernt Eric
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Measurement of Adhesion Forces With Optical Tweezers: System Description And Experimental Verification2003In: World congress on medical physics and biomedical engineering, 2003Conference paper (Other academic)
  • 128.
    Fällman, Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Gustavsson, Anna
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Cellular mechanisms of bacterial internalization counteracted by Yersinia2005In: International Review of Cytology: a survey of cell biology / [ed] Kwang W. Jeon, Elsevier, 2005, Vol. 246, p. 135-188Chapter in book (Refereed)
    Abstract [en]

    Upon host-cell contact, human pathogenic Yersinia species inject Yop virulence effectors into the host through a Type III secretion-and-translocation system. These virulence effectors cause a block in phagocytosis (YopE, YopT, YpkA, and YopH) and suppression of inflammatory mediators (YopJ). The Yops that block phagocytosis either interfere with the host cell actin regulation of Rho GTPases (YopE, YopT, and YpkA) or specifically and rapidly inactivate host proteins involved in signaling from the receptor to actin (YopH). The block in uptake has been shown to be activated following binding to Fc, Complement, and beta1-integrin receptors in virtually any kind of host cell. Thus, the use of Yersinia as a model system to study Yersinia-host cell interactions provides a good tool to explore signaling pathways involved in phagocytosis.

  • 129. Gabrielsen, Mads
    et al.
    Beckham, Katherine S H
    Feher, Victoria A
    Zetterström, Caroline E
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Wang, Dai
    Müller, Sylke
    Elofsson, Mikael
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Amaro, Rommie E
    Byron, Olwyn
    Roe, Andrew J
    Structural Characterisation of Tpx from Yersinia pseudotuberculosis Reveals Insights into the Binding of Salicylidene Acylhydrazide Compounds2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 2, p. e32217-Article in journal (Refereed)
    Abstract [en]

    Thiol peroxidase, Tpx, has been shown to be a target protein of the salicylidene acylhydrazide class of antivirulence compounds. In this study we present the crystal structures of Tpx from Y. pseudotuberculosis (ypTpx) in the oxidised and reduced states, together with the structure of the C61S mutant. The structures solved are consistent with previously solved atypical 2-Cys thiol peroxidases, including that for “forced” reduced states using the C61S mutant. In addition, by investigating the solution structure of ypTpx using small angle X-ray scattering (SAXS), we have confirmed that reduced state ypTpx in solution is a homodimer. The solution structure also reveals flexibility around the dimer interface. Notably, the conformational changes observed between the redox states at the catalytic triad and at the dimer interface have implications for substrate and inhibitor binding. The structural data were used to model the binding of two salicylidene acylhydrazide compounds to the oxidised structure of ypTpx. Overall, the study provides insights into the binding of the salicylidene acylhydrazides to ypTpx, aiding our long-term strategy to understand the mode of action of this class of compounds.

  • 130. Gavriljuk, Konstantin
    et al.
    Schartner, Jonas
    Seidel, Hans
    Dickhut, Clarissa
    Zahedi, Rene P.
    Hedberg, Christian
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Kötting, Carsten
    Gerwert, Klaus
    Unraveling the Phosphocholination Mechanism of the Legionella pneumophila Enzyme AnkX2016In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 55, no 31, p. 4375-4385Article in journal (Refereed)
    Abstract [en]

    The intracellular pathogen Legionella pneumophila infects lung macrophages and injects numerous effector proteins into the host cell to establish a vacuole for proliferation. The necessary interference with vesicular trafficking of the host is achieved by modulation of the function of Rab GTPases. The effector protein AnkX chemically modifies Rab1b and Rab35 by covalent phosphocholination of serine or threonine residues using CDP-choline as a donor. So far, the phosphoryl transfer mechanism and the relevance of observed autophosphocholination of AnkX remained disputable. We designed tailored caged compounds to make this type of enzymatic reaction accessible for time-resolved Fourier transform infrared difference spectroscopy. By combining spectroscopic and biochemical methods, we determined that full length AnkX is autophosphocholinated at Ser521, Thr620, and Thr943. However, autophosphocholination loses specificity for these sites in shortened constructs and does not appear to be relevant for the catalysis of the phosphoryl transfer. In contrast, transient phosphocholination of His229 in the conserved catalytic motif might exist as a short-lived reaction intermediate. Upon substrate binding, His229 is deprotonated and locked in this state, being rendered capable of a nucleophilic attack on the pyrophosphate moiety of the substrate. The proton that originated from His229 is transferred to a nearby carboxylic acid residue. Thus, our combined findings support a ping-pong mechanism involving phosphocholination of His229 and subsequent transfer of phosphocholine to the Rab GTPase. Our approach can be extended to the investigation of further nucleotidyl transfer reactions, which are currently of reemerging interest in regulatory pathways of host–pathogen interactions.

  • 131.
    Gekara, Nelson O.
    et al.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
    Jiang, Hui
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    The innate immune DNA sensor cGAS: A membrane, cytosolic, or nuclear protein?2019In: Science Signaling, ISSN 1945-0877, E-ISSN 1937-9145, Vol. 12, no 581, article id eaax3521Article in journal (Other academic)
    Abstract [en]

    Cyclic cGMP-AMP synthase (cGAS) alerts the innate immune system to the presence of foreign or damaged self-DNA inside the cell and is critical for the outcome of infections, inflammatory diseases, and cancer. Two studies now demonstrate that cGAS activation is regulated by differential subcellular localization through its non-enzymatic, N-terminal domain.

  • 132.
    Gillenius, Erik
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Urban, Constantin F
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    The adhesive protein invasin of Yersinia pseudotuberculosis induces neutrophil extracellular traps via β1 integrins2015In: Microbes and infection, ISSN 1286-4579, E-ISSN 1769-714X, Vol. 17, no 5, p. 327-336Article in journal (Refereed)
    Abstract [en]

    Yersinia pseudotuberculosis adhesive protein invasin is crucial for the bacteria to cross the intestine epithelium by binding to β1 integrins on M-cells and gaining access to the underlying tissues. After the crossing invasin can bind to β1 integrins on other cell surfaces, however effector proteins delivered by the type III secretion system Y. pseudotuberculosis efficiently inhibit potential immune responses induced by this interaction. Here, we use mutant Y. pseudotuberculosis strains lacking the type III secretion system and additionally invasin-expressing Escherichia coli to analyze neutrophil responses towards invasin. Our data reveals that invasin induces production of reactive oxygen species and release of chromatin into the extracellular milieu, which we confirmed to be neutrophil extracellular traps by immunofluorescence microscopy. This was mediated through β1 integrins and was dependent on both the production of reactive oxygen species and signaling through phosphoinositide 3-kinase. We therefore have gained insight into a potential role of integrins in inflammation and infection clearance that has not previously been described, suggesting that targeting of β1 integrins could be utilized as an adjunctive therapy against yersiniosis.

  • 133. Ginley, Brandon G
    et al.
    Emmons, Tiffany
    Lutnick, Brendon
    Urban, Constantin F
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Segal, Brahm H
    Sarder, Pinaki
    Computational detection and quantification of human and mouse neutrophil extracellular traps in flow cytometry and confocal microscopy2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, no 1, article id 17755Article in journal (Refereed)
    Abstract [en]

    Neutrophil extracellular traps (NETs) are extracellular defense mechanisms used by neutrophils, where chromatin is expelled together with histones and granular/cytoplasmic proteins. They have become an immunology hotspot, implicated in infections, but also in a diverse array of diseases such as systemic lupus erythematosus, diabetes, and cancer. However, the precise assessment of in vivo relevance in different disease settings has been hampered by limited tools to quantify occurrence of extracellular traps in experimental models and human samples. To expedite progress towards improved quantitative tools, we have developed computational pipelines to identify extracellular traps from an in vitro human samples visualized using the ImageStream® platform (Millipore Sigma, Darmstadt, Germany), and confocal images of an in vivo mouse disease model of aspergillus fumigatus pneumonia. Our two in vitro methods, tested on n = 363/n =145 images respectively, achieved holdout sensitivity/specificity 0.98/0.93 and 1/0.92. Our unsupervised method for thin lung tissue sections in murine fungal pneumonia achieved sensitivity/specificity 0.99/0.98 in n = 14 images. Our supervised method for thin lung tissue classified NETs with sensitivity/specificity 0.86/0.90. We expect that our approach will be of value for researchers, and have application in infectious and inflammatory diseases.

  • 134.
    Good, James A. D.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Andersson, Christopher
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Hansen, Sabine
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Wall, Jessica
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Krishnan, Syam
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Begum, Afshan
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Grundström, Christin
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Niemiec, Moritz Sebastian
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Vaitkevicius, Karolis
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Chorell, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Wittung-Stafshede, Pernilla
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sauer, Uwe H.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Sauer–Eriksson, A. Elisabeth
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Johansson, Jörgen
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Attenuating Listeria monocytogenes virulence by targeting the regulatory protein PrfA2016In: Cell chemical biology, ISSN 2451-9448, Vol. 23, no 3, p. 404-414Article in journal (Refereed)
    Abstract [en]

    The transcriptional activator PrfA, a member of the Crp/Fnr family, controls the expression of some key virulence factors necessary for infection by the human bacterial pathogen Listeria monocytogenes. Phenotypic screening identified ring-fused 2-pyridone molecules that at low micromolar concentrations attenuate L. monocytogenes infectivity by reducing the expression of virulence genes, without compromising bacterial growth. These inhibitors bind the transcriptional regulator PrfA and decrease its affinity for the consensus DNA binding site. Structural characterization of this interaction revealed that one of the ring-fused 2-pyridones, compound 1, binds within a hydrophobic pocket, located between the C- and N-terminal domains of PrfA, and interacts with residues important for PrfA activation. This indicates that these inhibitors maintain the DNA-binding helix-turn-helix motif of PrfA in a disordered state, thereby preventing a PrfA:DNA interaction. Ring-fused 2-pyridones represent a new class of chemical probes for studying virulence in L. monocytogenes.

  • 135.
    Good, James A. D.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Berretta, Giacomo
    Anthony, Nahoum G.
    Mackay, Simon P.
    The Discovery and Development of Eg5 Inhibitors for the Clinic2015In: Kinesins and Cancer / [ed] Frank Kozielski, Springer, 2015, p. 27-52Chapter in book (Refereed)
    Abstract [en]

    The mitotic kinesin Eg5 (also known as kinesin spindle protein, KSP, Kif11, a member of the kinesin-5 family) represents an attractive oncology drug target in the ongoing development of anti-mitotic drugs that selectively block mitosis through disruption to the mitotic spindle. In this state-of-the-art review, we outline the progress that has been made in the development of Eg5 inhibitors for clinical use. We evaluate the preclinical development and attributes of key Eg5 inhibitors that have undergone clinical evaluation or extensive preclinical optimisation, and discuss the medicinal chemistry strategies utilised in their design to overcome the challenges encountered during lead optimisation. We critically analyse the progress that has been made towards delivering clinical benefits, and the wider implications this has in the utility of mitotic kinesin inhibitors as prospective oncology drugs.

  • 136.
    Good, James A. D.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Kulén, Martina
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Silver, Jim
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Krishnan, K. Syam
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Bahnan, Wael
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Núñez-Otero, Carlos
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Nilsson, Ingela
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Wede, Emma
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    de Groot, Esmee
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Gylfe, Åsa
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Bergström, Sven
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Thiazolino 2-pyridone amide isosteres as inhibitors of Chlamydia trachomatis infectivity2017In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 60, no 22, p. 9393-9399Article in journal (Refereed)
    Abstract [en]

    Chlamydia trachomatis is a global health burden due to its prevalence as a sexually transmitted disease and as the causative agent of the eye infection trachoma. We recently discovered 3-amido thiazolino 2-pyridones which attenuated C. trachomatis infectivity without affecting host cell or commensal bacteria viability. We present here the synthesis and evaluation of nonhydrolyzable amide isosteres based on this class, leading to highly potent 1,2,3-triazole based infectivity inhibitors (EC50 ≤ 20 nM).

  • 137.
    Good, James A. D.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Silver, Jim
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Nunez-Otero, Carlos
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Bahnan, Wael
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Krishnan, K. Syam
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Salin, Olli
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Engström, Patrik
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Svensson, Richard
    Department of Pharmacy, Uppsala University, SE-751 23 Uppsala, Sweden; The Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Chemical Biology Consortium Sweden, Uppsala University, SE-751 23 Uppsala, Sweden.
    Artursson, Per
    Department of Pharmacy, Uppsala University, SE-751 23 Uppsala, Sweden; The Uppsala University Drug Optimization and Pharmaceutical Profiling Platform, Chemical Biology Consortium Sweden, Uppsala University, SE-751 23 Uppsala, Sweden.
    Gylfe, Åsa
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Bergström, Sven
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Thiazolino 2-Pyridone Amide Inhibitors of Chlamydia trachomatis Infectivity2016In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 59, no 5, p. 2094-2108Article in journal (Refereed)
    Abstract [en]

    The bacterial pathogen Chlamydia trachomatis is a global health burden currently treated with broad-spectrum antibiotics which disrupt commensal bacteria. We recently identified a compound through phenotypic screening that blocked infectivity of this intracellular pathogen without host cell toxicity (compound 1, KSK 120). Herein, we present the optimization of 1 to a class of thiazolino 2-pyridone amides that are highly efficacious (EC50 <= 100 nM) in attenuating infectivity across multiple serovars of C. trachomatis without host cell toxicity. The lead compound 21a exhibits reduced lipophilicity versus 1 and did not affect the growth or viability of representative commensal flora at 50 mu M. In microscopy studies, a highly active fluorescent analogue 37 localized inside the parasitiphorous inclusion, indicative of a specific targeting of bacterial components. In summary, we present a class of small molecules to enable the development of specific treatments for C. trachomatis.

  • 138. Greene, Sarah E.
    et al.
    Pinkner, Jerome S.
    Chorell, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Dodson, Karen W.
    Shaffer, Carrie L.
    Conover, Matt S.
    Livny, Jonathan
    Hadjifrangiskou, Maria
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Hultgren, Scott J.
    Pilicide ec240 Disrupts Virulence Circuits in Uropathogenic Escherichia coli2014In: mBio, ISSN 2161-2129, E-ISSN 2150-7511, Vol. 5, no 6, p. UNSP e02038-Article in journal (Refereed)
    Abstract [en]

    Chaperone-usher pathway (CUP) pili are extracellular organelles produced by Gram-negative bacteria that mediate bacterial pathogenesis. Small-molecule inhibitors of CUP pili, termed pilicides, were rationally designed and shown to inhibit type 1 or P piliation. Here, we show that pilicide ec240 decreased the levels of type 1, P, and S piliation. Transcriptomic and proteomic analyses using the cystitis isolate UTI89 revealed that ec240 dysregulated CUP pili and decreased motility. Paradoxically, the transcript levels of P and S pilus genes were increased during growth in ec240, even though the level of P and S piliation decreased. In contrast, the most downregulated transcripts after growth in ec240 were from the type 1 pilus genes. Type 1 pilus expression is controlled by inversion of the fimS promoter element, which can oscillate between phase on and phase off orientations. ec240 induced the fimS phase off orientation, and this effect was necessary for the majority of ec240's inhibition of type 1 piliation. ec240 increased levels of the transcriptional regulators SfaB and PapB, which were shown to induce the fimS promoter phase off orientation. Furthermore, the effect of ec240 on motility was abolished in the absence of the SfaB, PapB, SfaX, and PapX regulators. In contrast to the effects of ec240, deletion of the type 1 pilus operon led to increased S and P piliation and motility. Thus, ec240 dysregulated several uropathogenic Escherichia coli (UPEC) virulence factors through different mechanisms and independent of its effects on type 1 pilus biogenesis and may have potential as an antivirulence compound. IMPORTANCE CUP pili and flagella play active roles in the pathogenesis of a variety of Gram-negative bacterial infections, including urinary tract infections mediated by UPEC. These are extremely common infections that are often recurrent and increasingly caused by antibiotic-resistant organisms. Preventing piliation and motility through altered regulation and assembly of these important virulence factors could aid in the development of novel therapeutics. This study increases our understanding of the regulation of these virulence factors, providing new avenues by which to target their expression.

  • 139.
    Gurung, Jyoti M.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Amer, Ayad
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Francis, Monika
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Costa, Tiago
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Chen, Shiyun
    Zavialov, Anton V.
    Francis, Matthew S.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Heterologous complementation studies with the YscX and YscY protein families reveals a specificity for Yersinia pseudotuberculosis type III secretion2018In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 8, article id 80Article in journal (Refereed)
    Abstract [en]

    Type III secretion systems harbored by several Gram-negative bacteria are often used to deliver host-modulating effectors into infected eukaryotic cells. About 20 core proteins are needed for assembly of a secretion apparatus. Several of these proteins are genetically and functionally conserved in type III secretion systems of bacteria associated with invertebrate or vertebrate hosts. In the Ysc family of type III secretion systems are two poorly characterized protein families, the YscX family and the YscY family. In the plasmid-encoded Ysc-Yop type III secretion system of human pathogenic Yersinia species, YscX is a secreted substrate while YscY is its non-secreted cognate chaperone. Critically, neither an yscX nor yscY null mutant of Yersinia is capable of type III secretion. In this study, we show that the genetic equivalents of these proteins produced as components of other type III secretion systems of Pseudomonas aeruginosa (PscX and PscY), Aeromonas species (AscX and AscY), Vibrio species (VscX and VscY), and Photorhabdus luminescens (SctX and SctY) all possess an ability to interact with its native cognate partner and also establish cross-reciprocal binding to non-cognate partners as judged by a yeast two-hybrid assay. Moreover, a yeast three-hybrid assay also revealed that these heterodimeric complexes could maintain an interaction with YscV family members, a core membrane component of all type III secretion systems. Despite maintaining these molecular interactions, only expression of the native yscX in the near full-length yscX deletion and native yscY in the near full-length yscY deletion were able to complement for their general substrate secretion defects. Hence, YscX and YscY must have co-evolved to confer an important function specifically critical for Yersinia type III secretion.

  • 140. Gómez-Consarnau, Laura
    et al.
    Akram, Neelam
    Lindell, Kristoffer
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Pedersen, Anders
    Neutze, Richard
    Milton, Debra L
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    González, José M
    Pinhassi, Jarone
    Proteorhodopsin phototrophy promotes survival of marine bacteria during starvation2010In: PLoS biology, ISSN 1544-9173, E-ISSN 1545-7885, Vol. 8, article id e1000358Article in journal (Refereed)
    Abstract [en]

    Proteorhodopsins are globally abundant photoproteins found in bacteria in the photic zone of the ocean. Although their function as proton pumps with energy-yielding potential has been demonstrated, the ecological role of proteorhodopsins remains largely unexplored. Here, we report the presence and function of proteorhodopsin in a member of the widespread genus Vibrio, uncovered through whole-genome analysis. Phylogenetic analysis suggests that the Vibrio strain AND4 obtained proteorhodopsin through lateral gene transfer, which could have modified the ecology of this marine bacterium. We demonstrate an increased long-term survival of AND4 when starved in seawater exposed to light rather than held in darkness. Furthermore, mutational analysis provides the first direct evidence, to our knowledge, linking the proteorhodopsin gene and its biological function in marine bacteria. Thus, proteorhodopsin phototrophy confers a fitness advantage to marine bacteria, representing a novel mechanism for bacterioplankton to endure frequent periods of resource deprivation at the ocean’s surface.

  • 141.
    Hall, Michael
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Grundström, Christin
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Begum, Afshan
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Lindberg, Mikael J.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Sauer, Uwe H.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Johansson, Jörgen
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Sauer-Eriksson, A. Elisabeth
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Structural basis for glutathione-mediated activation of the virulence regulatory protein PrfA in Listeria2016In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, no 51, p. 14733-14738Article in journal (Refereed)
    Abstract [en]

    Infection by the human bacterial pathogen Listeria monocytogenes is mainly controlled by the positive regulatory factor A (PrfA), a member of the Crp/Fnr family of transcriptional activators. Published data suggest that PrfA requires the binding of a cofactor for full activity, and it was recently proposed that glutathione (GSH) could fulfill this function. Here we report the crystal structures of PrfA in complex with GSH and in complex with GSH and its cognate DNA, the hly operator PrfA box motif. These structures reveal the structural basis for a GSH-mediated allosteric mode of activation of PrfA in the cytosol of the host cell. The crystal structure of PrfAWT in complex only with DNA confirms that PrfAWT can adopt a DNA binding-compatible structure without binding the GSH activator molecule. By binding to PrfA in the cytosol of the host cell, GSH induces the correct fold of the HTH motifs, thus priming the PrfA protein for DNA interaction.

  • 142. Heckl, Dirk
    et al.
    Charpentier, Emmanuelle
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Department of Regulation in Infection Biology, Helmholtz Centre for Infection Research, Germany ; Department of Regulation in Infection Biology, Hannover Medical School, Hannover, Germany.
    Toward whole-transcriptome editing with CRISPR-Cas92015In: Molecular Cell, ISSN 1097-2765, E-ISSN 1097-4164, Vol. 58, no 4, p. 560-562Article in journal (Other academic)
    Abstract [en]

    Targeted regulation of gene expression holds huge promise for biomedical research. In a series of recent publications (Gilbert et al., 2014; Konermann et al., 2015; Zalatan et al., 2015), sophisticated, multiplex-compatible transcriptional activator systems based on the CRISPR-Cas9 technology and genome-scale libraries advance the field toward whole-transcriptome control.

  • 143.
    Henriksson, Maria
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Francis, Matthew
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Peden, Alex
    Aili, Margareta
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Stefansson, Kristina
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Palmer, Ruth
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Aitken, Alastair
    Hallberg, Bengt
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    A nonphosphorylated 14-3-3 binding motif on exoenzyme S that is functional in vivo2002In: European Journal of Biochemistry, ISSN 0014-2956, E-ISSN 1432-1033, Vol. 269, no 20, p. 4921-4929Article in journal (Refereed)
    Abstract [en]

    14-3-3 proteins play an important role in a multitude of signalling pathways. The interactions between 14-3-3 and other signalling proteins, such as Raf and KSR (kinase suppressor of Ras), occur in a phospho-specific manner. Recently, a phosphorylation-independent interaction has been reported to occur between 14-3-3 and several proteins, for example 5-phosphatase, p75NTR-associated cell death executor (NADE) and the bacterial toxin Exoenzyme S (ExoS), an ADP-ribosyltransferase from Pseudomonas aeruginosa. In this study we have identified the amino acid residues on ExoS, which are responsible for its specific interaction with 14-3-3. Furthermore, we show that a peptide derived from ExoS, containing the 14-3-3 interaction site, effectively competes out the interaction between ExoS and 14-3-3. In addition, competition with this peptide blocks ExoS modification of Ras in our Ras modification assay. We show that the ExoS protein interacts with all isoforms of the 14-3-3 family tested. Moreover, in vivo an ExoS protein lacking the 14-3-3 binding site has a reduced capacity to ADP ribosylate cytoplasmic proteins, e.g. Ras, and shows a reduced capacity to change the morphology of infected cells.

  • 144.
    Hernández, Sara B
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Cava, Felipe
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Environmental roles of microbial amino acid racemases2016In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 18, no 6, p. 1673-1685Article, review/survey (Refereed)
    Abstract [en]

    Enzymes catalysing the stereo-chemical inter-conversion of amino acids are known as amino acid racemases. In bacteria, these enzymes are fundamental to synthesize the D-Ala and D-Glu that are critical components of the peptidoglycan. In addition to this structural function in cell wall assembly, D-amino acids produced by microbial amino acid racemases have been described as relevant constituents in other prokaryotic structures (e.g. capsule, non-ribosomal peptides) and have been associated to growth fitness and to processes such as biofilm development, spore germination, and signalling. The recent discovery of broad spectrum racemases able to produce and release several D-amino acids to the environment suggests that these enzymes might have a great impact in microbial ecology. Consequently, new data on the biochemistry and regulation of racemases is key to understand the biological significance of D-enantiomers in nature, in particular their effect on microbial social networks. This review summarizes current knowledge on the environmental roles of bacterial racemases with an emphasis on the potential roles of the new broad spectrum enzymes in natural environments.

  • 145. Hille, Frank
    et al.
    Charpentier, Emmanuelle
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, Berlin 10117, Germany.
    CRISPR-Cas: biology, mechanisms and relevance2016In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 371, no 1707, article id 20150496Article, review/survey (Refereed)
    Abstract [en]

    Prokaryotes have evolved several defence mechanisms to protect themselves from viral predators. Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) display a prokaryotic adaptive immune system that memorizes previous infections by integrating short sequences of invading genomes-termed spacers-into the CRISPR locus. The spacers interspaced with repeats are expressed as small guide CRISPR RNAs (crRNAs) that are employed by Cas proteins to target invaders sequence-specifically upon a reoccurring infection. The ability of the minimal CRISPR-Cas9 system to target DNA sequences using programmable RNAs has opened new avenues in genome editing in a broad range of cells and organisms with high potential in therapeutical applications. While numerous scientific studies have shed light on the biochemical processes behind CRISPR-Cas systems, several aspects of the immunity steps, however, still lack sufficient understanding. This review summarizes major discoveries in the CRISPR-Cas field, discusses the role of CRISPR-Cas in prokaryotic immunity and other physiological properties, and describes applications of the system as a DNA editing technology and antimicrobial agent. This article is part of the themed issue 'The new bacteriology'.

  • 146. Hille, Frank
    et al.
    Richter, Hagen
    Wong, Shi Pey
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, Berlin, Germany; Institute for Biology, Humboldt University, Germany.
    Bratovic, Majda
    Ressel, Sarah
    Charpentier, Emmanuelle
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, Berlin, Germany; Institute for Biology, Humboldt University, Germany.
    The Biology of CRISPR-Cas: Backward and Forward2018In: Cell, ISSN 0092-8674, E-ISSN 1097-4172, Vol. 172, no 6, p. 1239-1259Article, review/survey (Refereed)
    Abstract [en]

    In bacteria and archaea, clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute an adaptive immune system against phages and other foreign genetic elements. Here, we review the biology of the diverse CRISPR-Cas systems and the major progress achieved in recent years in understanding the underlying mechanisms of the three stages of CRISPR-Cas immunity: adaptation, crRNA biogenesis, and interference. The ecology and regulation of CRISPR-Cas in the context of phage infection, the roles of these systems beyond immunity, and the open questions that propel the field forward are also discussed.

  • 147. Holm, Kare Olav
    et al.
    Nilsson, Kristina
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Hjerde, Erik
    Willassen, Nils-Peder
    Milton, Debra L.
    Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Complete genome sequence of Vibrio anguillarum strain NB10, a virulent isolate from the Gulf of Bothnia2015In: Standards in Genomic Sciences, ISSN 1944-3277, E-ISSN 1944-3277, Vol. 10, article id 60Article in journal (Refereed)
    Abstract [en]

    Vibrio anguillarum causes a fatal hemorrhagic septicemia in marine fish that leads to great economical losses in aquaculture world-wide. Vibrio anguillarum strain NB10 serotype O1 is a Gram-negative, motile, curved rod-shaped bacterium, isolated from a diseased fish on the Swedish coast of the Gulf of Bothnia, and is slightly halophilic. Strain NB10 is a virulent isolate that readily colonizes fish skin and intestinal tissues. Here, the features of this bacterium are described and the annotation and analysis of its complete genome sequence is presented. The genome is 4,373,835 bp in size, consists of two circular chromosomes and one plasmid, and contains 3,783 protein-coding genes and 129 RNA genes.

  • 148.
    Horvath, Istvan
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Weise, Christoph F
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Emma K
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Chorell, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sellstedt, Magnus
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Bengtsson, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Olofsson, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Hultgren, Scott J
    Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States.
    Chapman, Matthew
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Wolf-Watz, Magnus
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Almqvist, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Wittung-Stafshede, Pernilla
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Mechanisms of Protein Oligomerization: Inhibitor of Functional Amyloids Templates α-Synuclein Fibrillation2012In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 134, no 7, p. 3439-3444Article in journal (Refereed)
    Abstract [en]

    Small organic molecules that inhibit functional bacterial amyloid fibers, curli, are promising new antibiotics. Here we investigated the mechanism by which the ring-fused 2-pyridone FN075 inhibits fibrillation of the curli protein CsgA. Using a variety of biophysical techniques, we found that FN075 promotes CsgA to form off-pathway, non-amyloidogenic oligomeric species. In light of the generic properties of amyloids, we tested whether FN075 would also affect the fibrillation reaction of human α-synuclein, an amyloid-forming protein involved in Parkinson's disease. Surprisingly, FN075 stimulates α-synuclein amyloid fiber formation as measured by thioflavin T emission, electron microscopy (EM), and atomic force microscopy (AFM). NMR data on (15)N-labeled α-synuclein show that upon FN075 addition, α-synuclein oligomers with 7 nm radius form in which the C-terminal 40 residues remain disordered and solvent exposed. The polypeptides in these oligomers contain β-like secondary structure, and the oligomers are detectable by AFM, EM, and size-exclusion chromatography (SEC). Taken together, FN075 triggers oligomer formation of both proteins: in the case of CsgA, the oligomers do not proceed to fibers, whereas for α-synuclein, the oligomers are poised to rapidly form fibers. We conclude that there is a fine balance between small-molecule inhibition and templation that depends on protein chemistry.

  • 149.
    Hosseinzadeh, Ava
    et al.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Messer, Philipp K
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Urban, Constantin F
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Stable Redox-Cycling Nitroxide Tempol Inhibits NET Formation2012In: Frontiers in Immunology, ISSN 1664-3224, E-ISSN 1664-3224, Vol. 3, article id 391Article in journal (Refereed)
    Abstract [en]

    To prevent the spread of pathogens neutrophils as the first line of defense are able to release Neutrophil Extracellular Traps (NETs), a recently discovered form of immune response. Reactive oxygen species (ROS) have been shown to be essential for many different induction routes of NET formation. Therefore, pharmacological inhibition of ROS generation has implications for research and medicine related to NETs. The application of diphenylene iodonium (DPI), an inhibitor of NADPH oxidase activity, is limited due to its toxicity to host cells as well as microbes. Therefore, we investigated the effect of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) a membrane-permeable radical scavenger on NET formation triggered by phorbol esters and Candida albicans. We quantified the amount of NETs with two complementary methods, using a microscopic analysis and an online fluorescence-based assay. In line with removal of ROS, Tempol reduced the amount of NET formation by neutrophils challenged with those stimuli significantly. Since Tempol efficiently blocks NET formation in vitro, it might be promising to test the effect of Tempol in experimental models of disorders in which NETs probably have hazardous effects.

  • 150.
    Hosseinzadeh, Ava
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Rofougaran, Reza
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Vodnala, Munender
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Kötemann, A
    Hofer, Anders
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Urban, Constantin F.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Adenosine is a drugable negative regulator of neutrophil activity during Candida albicans infectionManuscript (preprint) (Other academic)
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