Light is required for efficient translation elongation and subsequent integration of the D1‐protein into Photosystem II

FEBS Letters

Eichacker, Lutz¹  van Wijk, Klaas J.² 

[1] Institute of Botany, University of Munich, 8000 Munich 19, Germany;Department of Biochemistry, Arrhenius Laboratories, Stockholm University, S-10691 Stockholm, Sweden

关键词: Assembly;    D1 reaction center protein;    Light regulation;    Photosystem II;    Photoinhibition;   

DOI  :  10.1016/0014-5793(96)00540-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The light dependence of translation and successive assembly of the D1 reaction center protein into Photosystem II subcomplexes was followed in fully developed chloroplasts isolated from the dark phase of diurnally grown spinach. The incorporation of synthesized D1 protein into Photosystem II (PSII) was analyzed by fractionation of radiolabeled unassembled protein and PSII (sub)complexes on sucrose density gradients. The ribosomes with attached nascent chains were recovered as pellets in the same gradients, and nascent chains of the D1 protein were immunoprecipitated. The analysis showed that absence of light during translation leads to an increased accumulation of polysome-bound D1 translation intermediates, indicating that light is required for efficient elongation of the D1 protein. The accumulation of the D1 protein and CP43 decreased three-fold in darkness, whereas accumulation of the D2 reaction center protein was not affected by light. In addition, light was also required for efficient incorporation of the D1 protein into the PSII core complex. In darkness, the newly synthesized D1 protein accumulated predominantly as unassembled protein or in PSII subcomplexes smaller than 100 kDa.

【 授权许可】

Unknown