Change search
ReferencesLink to record
Permanent link

Direct link
Dissection of homologous translocon operons reveals a distinct role for YopD in type III secretion by Yersinia pseudotuberculosis.
Umeå University, Faculty of Medicine, Molecular Biology.
Umeå University, Faculty of Science and Technology, Molecular Biology (Faculty of Science and Technology).
Umeå University, Faculty of Science and Technology, Molecular Biology (Faculty of Science and Technology).
Umeå University, Faculty of Science and Technology, Molecular Biology (Faculty of Science and Technology).
2003 (English)In: Microbiology, ISSN 1350-0872, Microbiology, Vol. 149, no 9, 2615-2626 p.Article in journal (Refereed) Published
Abstract [en]

The homologous pcrGVHpopBD and lcrGVHyopBD translocase operons of Pseudomonas aeruginosa and pathogenic Yersinia spp., respectively, are responsible for the translocation of anti-host effectors into the cytosol of infected eukaryotic cells. In Yersinia, this operon is also required for yop-regulatory control. To probe for key molecular interactions during the infection process, the functional interchangeability of popB/yopB and popD/yopD was investigated. Secretion of PopB produced in trans in a yopB null mutant of Yersinia was only observed when co-produced with its native chaperone PcrH, but this was sufficient to complement the yopB translocation defect. The Yersinia yopD null mutant synthesized and secreted PopD even in the absence of native PcrH, yet this did not restore YopD-dependent yop-regulatory control or effector translocation. Thus, this suggests that key residues in YopD, which are not conserved in PopD, are essential for functional Yersinia type III secretion.

Place, publisher, year, edition, pages
2003. Vol. 149, no 9, 2615-2626 p.
National Category
Medical and Health Sciences
URN: urn:nbn:se:umu:diva-4145DOI: 10.1099/mic.0.26322-0PubMedID: 12949185OAI: diva2:143126
Available from: 2004-10-06 Created: 2004-10-06 Last updated: 2010-02-24Bibliographically approved
In thesis
1. Type III secretion- the various functions of the translocon operon in bacterial pathogenesis
Open this publication in new window or tab >>Type III secretion- the various functions of the translocon operon in bacterial pathogenesis
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In order to establish colonisation of a human host, pathogenic Yersinia use a type III protein secretion system to directly intoxicate host immune cells. Activation of this system requires target cell contact and is a highly regulated process. Both the intoxication and regulation events depend on the lcrGVHyopBD translocon operon, which is highly conserved in many bacterial pathogens. In this study, the role of individual operon members was analysed and functional domains identified by using the highly homologous pcrGVHpopBD operon of P. aeruginosa as a comparative tool.

Yersinia spp. and P. aeruginosa were shown to form translocation pores of a similar size that promoted equally efficient protein delivery. A strong dependency on interactions between native translocator(s) in protein delivery was revealed, suggesting that each pathogen has delicately fine-tuned this process to suit its own infection niche. In particular, the C-terminus of YopD was shown to possess functional specificity for effector delivery in Yersinia that could not be conferred by the comparable region in homologous PopD. Moreover, a role for LcrV and PcrV in substrate recognition during the protein delivery process was excluded.

The N-terminus of LcrH was recognized as a unique regulatory domain, mediating formation of LcrH-YscY regulatory complexes in Yersinia, while equivalent complexes with analogous proteins were not formed in P. aeruginosa. These results compliment the idea that a negative regulatory pathway involving LcrH, YopD, LcrQ and YscY is unique to Yersinia.

Finally, PcrH was identified as a new member of the translocator class of chaperones, being essential for assembly of a functional PopB/PopD mediated translocon in P. aeruginosa. However, in contrast to the other members of this family, PcrH was dispensable for type III regulation. Moreover, both LcrH and PcrH were shown to possess tetratricopeptide repeats crucial for their chaperone function. One tetratricopeptide repeat mutant in LcrH was even isolated that failed to secrete both YopB and YopD substrates, even though stability was maintained. This demonstrates for the first time that LcrH has a role in substrate secretion in addition to its critical role in promoting substrate stability.

Place, publisher, year, edition, pages
Umeå: Molekylärbiologi, 2004. 82 p.
Molecular biology, Yersinia, Pseudomonas aeruginosa, type III secretion, chaperone, translocation, regulation, lcrGVHyopBD, pcrGVHpopBD, Molekylärbiologi
National Category
Biochemistry and Molecular Biology
Research subject
Molecular Biology
urn:nbn:se:umu:diva-331 (URN)91-7305-712-6 (ISBN)
Public defence
2004-11-05, Major Groove, 6L, NUS, Umeå Universitet, 90187, Umeå, 09:00
Available from: 2004-10-06 Created: 2004-10-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Bröms, JeanetteForslund, Anna-LenaForsberg, ÅkeFrancis, Matthew
By organisation
Molecular BiologyMolecular Biology (Faculty of Science and Technology)
In the same journal
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 66 hits
ReferencesLink to record
Permanent link

Direct link