Stabilization of photosystem two dimers by phosphorylation: Implication for the regulation of the turnover of D1 protein

FEBS Letters

Kruse, Olaf¹  Barber, James¹  Zheleva, Daniella¹ 

[1] Wolfson Laboratories, Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AY, UK

关键词: Photosystem II;    Phosphorylation;    D1 protein;    Dimer/monomer interconversion;    Turnover;    Photoinhibition;    PSI and PSII;    photosystem I and II;    LHC-II;    light harvesting complex II;   

DOI  :  10.1016/S0014-5793(97)00439-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A general feature of many membrane protein complexes is that they have oligomeric organisation in vivo. Photosystem II (PSII) is one such example and the possible functional significance of this is explored in this work. Monomeric and dimeric forms of the core complex of PSII have been isolated from non-phosphorylated and phosphorylated thylakoid membranes prepared from spinach. These complexes had the same complement of proteins including, D1 (PsbA), D2 (PsbD), α-(PsbE) and β-(PsbF) subunits of cytochrome b ₅₅₉, CP47 (PsbB), CP43 (PsbC), 33 kDa (PsbO) extrinsic protein and some other smaller subunits, such as PsbH, but did not contain Cab proteins. D1, D2, CP43 and PsbH were the phosphorylated components. Whether phosphorylated or not, the dimeric form of the PSII complex was more stable than the monomeric form. However, when treated with photoinhibitory light the isolated dimers converted to monomers in their non-phosphorylated state but not when phosphorylated. Phosphorylation, however, did not prevent photoinhibition as judged by the loss of oxygen evolving activity. A model is suggested for the role of PSII phosphorylation in controlling the conversion of dimeric PSII to its monomeric form and in this way regulate the rate of degradation of D1 protein during the photoinhibitory repair cycle.

【 授权许可】

Unknown