ATP and light regulate D1 protein modification and degradation Role of D1* in photoinhibition

FEBS Letters

Aro, Eva-Mari¹  Kettunen, Reetta¹  Tyystjärvi, Esa¹ 

[1] Department of Biology, University of Turku, SF.-20500 Turku, Finland

关键词: DI protein;    Phosphorylation;    Photoinhibition;    Photosystem II;    DI*;    modified form of the D1 protein;    P680;    primary donor of photosystem II;    PPFD;    photosynthetic photon flux density;    PSII;    photosystem II;   

DOI  :  10.1016/0014-5793(92)80320-G

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have recently shown that during in vivo photoinhibition the D1 protein is degraded via a modified form, designated D1*. Depending on light conditions, the amount of D1* varies in leaves between 0 and 50% of total D1 content. By isolating thylakoids from leaves acclimated to different light levels, and performing photoinhibition experiments on these thylakoids, the following results on D1 protein degradation were obtained: (1) the protease involved in D1 degradation requires activation by light; (ii) neither acceptor nor donor side photoinhibition of PSII induces formation of D1* in vitro; (iii) in isolated thylakoids, the transformation of D1 to D1* can be induced in low light in the presence of ATP, which suggests that D1* is a phosphorylated form of the D1 protein; (iv) D1*, induced either in vivo or in vitro, is much less susceptible to degradation during illumination of isolated thylakoids than the original D1 protein. We suggest that the modification to D1* is a means to prevent disassembly of photodamaged photosystem II complex in appressed membranes.

【 授权许可】

Unknown