HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 281, Issue 48, 36758-36766, December 1, 2006

This Article Full Text Full Text (PDF) All Versions of this Article: 281/48/36758    most recent M606797200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nakamura, K. Articles by Hihara, Y. Search for Related Content PubMed PubMed Citation Articles by Nakamura, K. Articles by Hihara, Y. Social Bookmarking                      What's this?

Photon Flux Density-dependent Gene Expression in Synechocystis sp. PCC 6803 Is Regulated by a Small, Redox-responsive, LuxR-type Regulator^*

From the Department of Biochemistry and Molecular Biology, Faculty of Science, Saitama University, Saitama 338-8570, Japan

The expression of many cyanobacterial genes is regulated by the redox state of the photosynthetic electron transport chain. However, factors involved in this regulation have not been identified. In this study, we demonstrate that a small LuxR-type regulator in Synechocystis sp. PCC 6803, PedR (Ssl0564), senses the activity of photosynthetic electron transport to achieve the photon flux density-dependent transcriptional regulation. PedR is constitutively expressed in Synechocystis cells and exists as a dimer bridged by intermolecular disulfide bond(s). It activates the expression of chlL, chlN, chlB, and slr1957 and represses that of ndhD2, rpe, and the pedR (ssl0564)-sll0296 operon under conditions where the activity of photosynthetic electron transport is low. When the supply of reducing equivalents from photosynthetic electron transport chain increases upon the elevation of photon flux density, PedR is inactivated through its conformational change within 5 min. This mechanism enables transient induction or repression of the target genes in response to sudden changes in light environment. The fact that orthologs of PedR are conserved among all the cyanobacterial genomes sequenced so far indicates that this type of transcriptional regulation is essential for cyanobacteria to acclimate to changing environments.

Received for publication, July 17, 2006 , and in revised form, September 28, 2006.

^* This work was supported by a grant-in-aid for young scientists from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (to Y. H.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ Present address: Laboratory of Molecular Biology, Inst. for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.

² To whom correspondence should be addressed: Dept. of Biochemistry and Molecular Biology, Faculty of Science, Saitama University, 255 Shimo-Okubo, Saitama 338-8570, Japan. Tel.: 81-48-858-3396; Fax: 81-48-858-3384; E-mail: hihara{at}molbiol.saitama-u.ac.jp.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. Muramatsu, K. Sonoike, and Y. Hihara Mechanism of downregulation of photosystem I content under high-light conditions in the cyanobacterium Synechocystis sp. PCC 6803 Microbiology, March 1, 2009; 155(3): 989 - 996. [Abstract] [Full Text] [PDF]

				Y. Seino, T. Takahashi, and Y. Hihara The Response Regulator RpaB Binds to the Upstream Element of Photosystem I Genes To Work for Positive Regulation under Low-Light Conditions in Synechocystis sp. Strain PCC 6803 J. Bacteriol., March 1, 2009; 191(5): 1581 - 1586. [Abstract] [Full Text] [PDF]

				A. Ishii and Y. Hihara An AbrB-Like Transcriptional Regulator, Sll0822, Is Essential for the Activation of Nitrogen-Regulated Genes in Synechocystis sp. PCC 6803 Plant Physiology, September 1, 2008; 148(1): 660 - 670. [Abstract] [Full Text] [PDF]