OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) A correction has been published OA All Versions of this Article: 143/4/1547    most recent pp.107.096396v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Park, S. Articles by Melis, A. Search for Related Content PubMed PubMed Citation Articles by Park, S. Articles by Melis, A. Pubmed/NCBI databases Protein UniGene Substance via MeSH Agricola Articles by Park, S. Articles by Melis, A.

BIOENERGETICS AND PHOTOSYNTHESIS

REP27, a Tetratricopeptide Repeat Nuclear-Encoded and Chloroplast-Localized Protein, Functions in D1/32-kD Reaction Center Protein Turnover and Photosystem II Repair from Photodamage^1,[OA]

Department of Plant and Microbial Biology, University of California, Berkeley, California, 94720–3102

The goal of this research is elucidation of the molecular mechanism for the unique photosystem II (PSII) damage and repair cycle in chloroplasts. A frequently occurring, irreversible photooxidative damage inhibits the PSII charge separation reaction and stops photosynthesis. The chloroplast PSII repair process rectifies this adverse effect by selectively removing and replacing the photoinactivated D1/32-kD reaction center protein (the chloroplast-encoded psbA gene product) from the massive (>1,000 kD) water-oxidizing and O₂-evolving PSII holocomplex. DNA insertional mutagenesis in the model organism Chlamydomonas reinhardtii was applied for the isolation and characterization of rep27, a repair-aberrant mutant. Gene cloning and biochemical analyses in this mutant resulted in the identification of REP27, a nuclear gene encoding a putative chloroplast-targeted protein, which is specifically required for the completion of the D1 turnover process but is not essential for the de novo biogenesis and assembly of the PSII holocomplex in this model green alga. The REP27 protein contains two highly conserved tetratricopeptide repeats, postulated to facilitate the psbA mRNA cotranslational insertion of the nascent D1 protein in the existing PSII core template. Elucidation of the PSII repair mechanism may reveal the occurrence of hitherto unknown regulatory and catalytic reactions for the selective in situ replacement of specific proteins from within multiprotein complexes.

² Present address: Department of Biochemistry, Faculty of Science Mahidol University, Rama VI Road, Bangkok 10400, Thailand.

³ Present address: Institute of Chemistry, Umea University, SE–901 87, Umea, Sweden.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Anastasios Melis (melis{at}nature.berkeley.edu).

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.107.096396

^* Corresponding author; e-mail melis{at}nature.berkeley.edu; fax 510–642–4995.

Received January 23, 2007; accepted February 22, 2007; published March 2, 2007.

This article has been cited by other articles:

				D. Dewez, S. Park, J. G. Garcia-Cerdan, P. Lindberg, and A. Melis Mechanism of REP27 Protein Action in the D1 Protein Turnover and Photosystem II Repair from Photodamage Plant Physiology, September 1, 2009; 151(1): 88 - 99. [Abstract] [Full Text] [PDF]