Document Detail

Protection by α-tocopherol of the repair of photosystem II during photoinhibition in Synechocystis sp. PCC 6803.
MedLine Citation:
PMID:  21074511     Owner:  NLM     Status:  In-Data-Review    
α-Tocopherol is a lipophilic antioxidant that is an efficient scavenger of singlet oxygen. We investigated the role of α-tocopherol in the protection of photosystem II (PSII) from photoinhibition using a mutant of the cyanobacterium Synechocystis sp. PCC 6803 that is deficient in the biosynthesis of α-tocopherol. The activity of PSII in mutant cells was more sensitive to inactivation by strong light than that in wild-type cells, indicating that lack of α-tocopherol enhances the extent of photoinhibition. However, the rate of photodamage to PSII, as measured in the presence of chloramphenicol, which blocks the repair of PSII, did not differ between the two lines of cells. By contrast, the repair of PSII from photodamage was suppressed in mutant cells. Addition of α-tocopherol to cultures of mutant cells returned the extent of photoinhibition to that in wild-type cells, without any effect on photodamage. The synthesis de novo of various proteins, including the D1 protein that plays a central role in the repair of PSII, was suppressed in mutant cells under strong light. These observations suggest that α-tocopherol promotes the repair of photodamaged PSII by protecting the synthesis de novo of the proteins that are required for recovery from inhibition by singlet oxygen.
Shuhei Inoue; Kayoko Ejima; Eri Iwai; Hidenori Hayashi; Jens Appel; Esa Tyystjärvi; Norio Murata; Yoshitaka Nishiyama
Publication Detail:
Type:  Journal Article     Date:  2010-11-11
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  1807     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  2011 Feb 
Date Detail:
Created Date:  2010-12-17     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  236-41     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 Elsevier B.V. All rights reserved.
Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan.
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