Nejvíce citovaný článek - PubMed ID 10809009
Degradation of the Photosystem II D1 and D2 proteins in different strains of the cyanobacterium Synechocytis PCC 6803 varying with respect to the type and level of psbA transcript
The growth of plants, algae, and cyanobacteria relies on the catalytic activity of the oxygen-evolving PSII complex, which uses solar energy to extract electrons from water to feed into the photosynthetic electron transport chain. PSII is proving to be an excellent system to study how large multi-subunit membrane-protein complexes are assembled in the thylakoid membrane and subsequently repaired in response to photooxidative damage. Here we summarize recent developments in understanding the biogenesis of PSII, with an emphasis on recent insights obtained from biochemical and structural analysis of cyanobacterial PSII assembly/repair intermediates. We also discuss how chlorophyll synthesis is synchronized with protein synthesis and suggest a possible role for PSI in PSII assembly. Special attention is paid to unresolved and controversial issues that could be addressed in future research.
The selective replacement of photodamaged D1 protein within the multisubunit photosystem II (PSII) complex is an important photoprotective mechanism in chloroplasts and cyanobacteria. FtsH proteases are involved at an early stage of D1 degradation, but it remains unclear how the damaged D1 subunit is recognized, degraded, and replaced. To test the role of the N-terminal region of D1 in PSII biogenesis and repair, we have constructed mutants of the cyanobacterium Synechocystis sp PCC 6803 that are truncated at the exposed N terminus. Removal of 5 or 10 residues blocked D1 synthesis, as assessed in radiolabeling experiments, whereas removal of 20 residues restored the ability to assemble oxygen-evolving dimeric PSII complexes but inhibited PSII repair at the level of D1 degradation. Overall, our results identify an important physiological role for the exposed N-terminal tail of D1 at an early step in selective D1 degradation. This finding has important implications for the recognition of damaged D1 and its synchronized replacement by a newly synthesized subunit.
- MeSH
- autotrofní procesy účinky léků účinky záření MeSH
- biologické modely MeSH
- dimerizace MeSH
- fluorescenční spektrometrie MeSH
- fotosystém II (proteinový komplex) chemie metabolismus MeSH
- linkomycin farmakologie MeSH
- molekulární sekvence - údaje MeSH
- mutace genetika MeSH
- mutantní proteiny metabolismus MeSH
- podjednotky proteinů chemie metabolismus MeSH
- posttranslační úpravy proteinů * účinky léků účinky záření MeSH
- sekundární struktura proteinů MeSH
- sekvence aminokyselin MeSH
- světlo MeSH
- Synechocystis cytologie účinky léků metabolismus účinky záření MeSH
- tylakoidy účinky léků metabolismus účinky záření MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fotosystém II (proteinový komplex) MeSH
- linkomycin MeSH
- mutantní proteiny MeSH
- podjednotky proteinů MeSH
