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The HCF136 protein is essential for assembly of the photosystem II reaction center in Arabidopsis thaliana
Author(s) -
Plücken Henning,
Müller Bernd,
Grohmann Dina,
Westhoff Peter,
Eichacker Lutz A
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)03634-7
Subject(s) - photosystem ii , biogenesis , thylakoid , arabidopsis thaliana , photosynthetic reaction centre , photosystem i , cytochrome b6f complex , arabidopsis , biology , chemistry , biophysics , cytochrome , photosystem , mutant , biochemistry , chloroplast , microbiology and biotechnology , photosynthesis , gene , enzyme
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 b 6 f 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 b 559 . We conclude that HCF136p is essential for assembly of the RC of PSII and discuss its function as a chaperone‐like assembly factor.