Redox signaling: globalization of gene expression.
Here we show that the extent of electron flow through the cbb(3) oxidase of Rhodobacter sphaeroides is inversely related to the expression levels of those photosynthesis genes that are under control of the PrrBA two-component activation system: the greater the electron flow, the stronger the inhibitory signal generated by the cbb(3) oxidase to repress photosynthesis gene expression. Using site-directed mutagenesis, we show that intramolecular electron transfer within the cbb(3) oxidase is involved in signal generation and transduction and this signal does not directly involve the intervention of molecular oxygen. In addition to the cbb(3) oxidase, the redox state of the quinone pool controls the transcription rate of the puc operon via the AppA-PpsR antirepressor-repressor system. Together, these interacting regulatory circuits are depicted in a model that permits us to understand the regulation by oxygen and light of photosynthesis gene expression in R.SPHAEROIDES:
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Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Medical School, 6431 Fannin, Houston, TX 77030, USA.
Kaplan
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D000935:Antifungal Agents / Q000494:pharmacology; D001426:Bacterial Proteins; D015153:Blotting, Western; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D003576:Electron Transport Complex IV / Q000737:chemistry*; D004583:Electrons; D004591:Electrophoresis, Polyacrylamide Gel; D015971:Gene Expression Regulation, Enzymologic; D007476:Ionophores / Q000494:pharmacology; D008027:Light; D008689:Methacrylates; D008954:Models, Biological; D016297:Mutagenesis, Site-Directed; D009876:Operon; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics; D012097:Repressor Proteins / Q000737:chemistry; D012242:Rhodobacter sphaeroides / Q000737:chemistry*; D015398:Signal Transduction; D013053:Spectrophotometry; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic; D014466:Ultraviolet Rays; D014475:Uncoupling Agents / Q000494:pharmacology
D000935:Antifungal Agents; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D007476:Ionophores; D008689:Methacrylates; D012097:Repressor Proteins; D013844:Thiazoles; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C030517:myxothiazol; C414443:cbb3 oxidase; D003576:Electron Transport Complex IV; D010100:Oxygen