title: Identification of the correct form of the mis-annotated response regulator Rre1 from the cyanobacterium Synechocystis sp. PCC 6803.
abstract: Two-component systems have been extensively described in the control of gene expression in response to different environmental signals in the cyanobacterium Synechocystis sp. PCC 6803. The Hik34-Rre1 two-component system has been shown to regulate a set of genes under certain stress conditions. Some evidence indicates that another histidine kinase, probably Hik2, is acting upstream of Rre1 in the regulation of some genes in response to hyperosmotic and salt stress. In the present study, a mis-annotation of the Rre1 protein has been identified and the correct version has been functionally characterized in vitro. By using EMSA assays, we have demonstrated that phosphorylation of Rre1 by Hik2 increases the affinity of the response regulator for the adhA promoter region, a gene that has been demonstrated previously to be specifically regulated by the Hik34-Rre1 system. These results suggest that Hik2 might cooperate with Hik34 in the regulation of the adhA gene by transferring the phosphoryl group to Rre1 under salt and hyperosmotic stress conditions.
authors.affiliation: Institute of Plant Biochemistry and Photosynthesis, University of Seville/Spanish Research Council. Avda. Americo Vespucio 49, E-41092 Seville, Spain rvidal@us.es.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Vidal
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000378:metabolism*; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000378:metabolism; D013312:Stress, Physiological; D046939:Synechocystis / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D012965:Sodium Chloride; D011494:Protein Kinases; D000071677:Histidine Kinase
keywords: hik2; histidine kinase; start codon; two-component system