JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Li, H.
Right arrow Articles by Sherman, L. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Li, H.
Right arrow Articles by Sherman, L. A.

Journal of Bacteriology, August 2000, p. 4268-4277, Vol. 182, No. 15
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

A Redox-Responsive Regulator of Photosynthesis Gene Expression in the Cyanobacterium Synechocystis sp. Strain PCC 6803

Hong Li and Louis A. Sherman*

Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907

Received 21 December 1999/Accepted 26 April 2000

We have identified genes in the unicellular cyanobacterium Synechocystis sp. strain PCC 6803 that are involved with redox control of photosynthesis and pigment-related genes. The genes, rppA (sll0797) and rppB (sll0798), represent a two-component regulatory system that controls the synthesis of photosystem II (PSII) and PSI genes, in addition to photopigment-related genes. rppA (regulator of photosynthesis- and photopigment-related gene expression) and rppB exhibit strong sequence similarity to prokaryotic response regulators and histidine kinases, respectively. In the wild type, the steady-state mRNA levels of PSII reaction center genes increased when the plastoquinone (PQ) pool was oxidized and decreased when the PQ pool was reduced, whereas transcription of the PSI reaction center genes was affected in an opposite fashion. Such results suggested that the redox poise of the PQ pool is critical for regulation of the photosystem reaction center genes. In Delta rppA, an insertion mutation of rppA, the PSII gene transcripts were highly up-regulated relative to the wild type under all redox conditions, whereas transcription of phycobilisome-related genes and PSI genes was decreased. The higher transcription of the psbA gene in Delta rppA was manifest by higher translation of the D1 protein and a concomitant increase in O2 evolution. The results demonstrated that RppA is a regulator of photosynthesis- and photopigment-related gene expression, is involved in the establishment of the appropriate stoichiometry between the photosystems, and can sense changes in the PQ redox poise.

* Corresponding author. Mailing address: Department of Biological Sciences, Purdue University, 1392 Lilly Hall of Life Sciences, West Lafayette, IN 47907-1392. Phone: (765) 494-8106. Fax: (765) 496-1495. E-mail: lsherman{at}bilbo.bio.purdue.edu.

Journal of Bacteriology, August 2000, p. 4268-4277, Vol. 182, No. 15
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2000 by the American Society for Microbiology. All rights reserved.