umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Characterization of the plastid-localized inactive FtsHis of Arabidopsis thaliana
Umeå University, Faculty of Science and Technology, Department of Chemistry.ORCID iD: 0000-0001-6970-7221
Umeå University, Faculty of Science and Technology, Department of Chemistry.
Umeå University, Faculty of Science and Technology, Department of Chemistry.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

In the genome of Arabidopsis thaliana five genes encode members of the FtsH (Filamentation temperature sensitive protein H) protease family with mutations or deletions in their proteolytic site. Despite of not being active proteases these so called FtsHi (i for inactive) enzymes still seem to be highly important for plant development. All five enzymes have been localized within the plant chloroplast, most of them seem to be inserted in the chloroplast envelope. As homozygous ftshi mutants are seed lethal, here we compared different heterozygous ftshi mutants with respect to their growth at various light periods and at semi-natural growth conditions in the field. Their photosynthetic efficiency was evaluated by pulse-amplitude modulated fluorescence and the composition of their photosynthetic complexes was analysed by native polyacrylamide gel electrophoresis. Co-expression analyses were performed to find clues about the function of the five FtsHi inactive proteases.

Keyword [en]
Arabidopsis, chloroplast, inactive FtsH protease
National Category
Biochemistry and Molecular Biology Plant Biotechnology
Research subject
Biochemistry
Identifiers
URN: urn:nbn:se:umu:diva-125815OAI: oai:DiVA.org:umu-125815DiVA: diva2:972476
Funder
Swedish Energy Agency, 2012-005889​
Available from: 2016-09-21 Created: 2016-09-19 Last updated: 2016-09-23
In thesis
1. Characterization of auxiliary membrane proteins in the chloroplast of Arabidopsis thaliana
Open this publication in new window or tab >>Characterization of auxiliary membrane proteins in the chloroplast of Arabidopsis thaliana
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Karakterisering av membran-lokaliserade hjälparproteiner i kloroplasten hos växten backtrav
Abstract [en]

In nature, sessile plants have to adapt to their environment and to the never ending changes they are exposed to. They do so mainly by proteomic and metabolomic changes. In all cells, there are complex networks of auxiliary proteins that are responsible for quality control of all the cell's proteins. The auxiliary proteins are divided into chaperones and proteases, and these are further separated into different groups. Chaperones help other proteins in terms of stability and folding. In order for a protein to achieve its function, the three-dimensional structure has to be precise. A protease is a helper protein that is able to break peptide bonds in a process termed proteolysis. Chaperones and proteases can work independently, but sometimes the chaperone unfolds the substrate of the protease to ensure full degradation of the protein. In some cases, the chaperone and the protease functions are combined in one protein.

All proteins studied within this thesis are localized in the chloroplast, the organelle that originated from cyanobacteria, in which plants and algae convert the energy from sunlight into carbohydrates in the process called photosynthesis. Molecular oxygen is released as a by-product, and carbon dioxide is consumed. Photosystem II (PSII), one of the major protein complexes involved in photosynthesis, consists of more than 30 protein subunits, where around half of them are termed low molecular weight (LMW) proteins with a molecular size less than 10 kDa. In this thesis, data identifying one PSII LMW protein, PsbY, as a chaperone for the PSII subcomplex Cytochrome b559 are presented. In the absence of PsbY, Arabidopsis plants were more sensitive to photoinhibition, and the protective circular electron transport around PSII is completely blocked.

Data on members of the Filamentation temperature sensitive protein H (FtsH) protease family are also discussed, with a focus on FtsH11 and FtsHi1-i5. Members of the FtsH protease family carry a protease domain and a chaperone domain. Our data show that FtsH11 has an influence on the structure and function of chloroplasts of Arabidopsis plants grown under continuous light along with protein import into the same. FtsHi1-5 are five members with mutations within the proteolytic motif, most probably rendering them proteolytically inactive, hence they are referred to as ''inactive FtsH proteases''. Knock-out plants of the inactive members are embryo lethal, and knock-down plants grow slower than wild type, probably because of an affected level of plastid proteins at the translational level.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2016. 52 p.
Keyword
Arabidopsis, chaperone, chloroplast, Cytochrome b559, FtsH, membrane proteins, photosynthesis, Photosystem II, protease, PsbY., Arabidopsis, chaperone, Cytochrome b559, fotosyntes, fotosystem II, FtsH, kloroplast, membranprotein, proteas, PsbY.
National Category
Biochemistry and Molecular Biology Plant Biotechnology
Research subject
Biochemistry
Identifiers
urn:nbn:se:umu:diva-125819 (URN)978-91-7601-480-6 (ISBN)
Public defence
2016-10-10, N450, Naturvetarhuset, Umeå, 10:00 (English)
Opponent
Supervisors
Funder
Swedish Energy Agency, 2012-005889​
Note

Avhandlingen är skriven på engelska, men innehåller också en enkel sammanfattning på svenska. 

Available from: 2016-09-26 Created: 2016-09-19 Last updated: 2016-09-23Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
von Sydow, LottaMielke, KatiFunk, Christiane
By organisation
Department of Chemistry
Biochemistry and Molecular BiologyPlant Biotechnology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 774 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf