The HCF136 protein is essential for assembly of the photosystem II reaction center in Arabidopsis thaliana

FEBS Letters

Grohmann, Dina¹  Plücken, Henning¹  Eichacker, Lutz A²  Müller, Bernd²  Westhoff, Peter¹ 

[1] Institut für Entwicklungs- und Molekularbiologie der Pflanzen, Heinrich-Heine-Universität, Universitätsstrasse 1, 40225 Düsseldorf, Germany;Botanisches Institut der Ludwig-Maximilians-Universität, Menzingerstrasse 67, 80638 München, Germany

关键词: Assembly;    HCF136p;    Photosystem II;    High chlorophyll fluorescence (hcf);    Blue native PAGE;   

DOI  :  10.1016/S0014-5793(02)03634-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Hcf136 encodes a hydrophilic protein localized in the lumen of stroma thylakoids. Its mutational inactivation in Arabidopsis thaliana results in a photosystem II (PHII)-less phenotype. Under standard illumination, PSII is not detectable and the amount of photosystem I (PSI) is reduced, which implies that HCF136p may be required for photosystem biogenesis in general. However, at low light, a comparison of mutants with defects in PSII, PSI, and the cytochrome b₆f complex reveals that HCF136p regulates selectively biogenesis of PSII. We demonstrate by in vivo radiolabeling of hcf136 that biogenesis of the reaction center (RC) of PSII is blocked. Gel blot analysis and affinity chromatography of solubilized thylakoid membranes suggest that HCF136p associates with a PSII precomplex containing at least D2 and cytochrome b₅₅₉. We conclude that HCF136p is essential for assembly of the RC of PSII and discuss its function as a chaperone-like assembly factor.

【 授权许可】

Unknown