title: Conserved two-component Hik34-Rre1 module directly activates heat-stress inducible transcription of major chaperone and other genes in Synechococcus elongatus PCC 7942.
abstract: Bacteria and other organisms, including cyanobacteria, employ two-component signal transducing modules comprising histidine kinases and response regulators to acclimate to changing environments. While the number and composition of these modules differ among cyanobacteria, two response regulators that contain DNA binding domains, RpaB and Rre1, are conserved in all sequenced cyanobacterial genomes and are essential for viability. Although RpaB negatively or positively regulates high light and other stress-responsive gene expression, little is known about the function of Rre1. Here, they investigated the direct regulatory targets of Rre1 in the cyanobacterium Synechococcus elongatus PCC 7942. Chromatin immunoprecipitation and high-density tiling array analysis were used to map Rre1 binding sites. The sites included promoter regions for chaperone genes such as dnaK2, groESL-1, groEL-2, hspA and htpG, as well as the group 2 sigma factor gene rpoD2. In vivo and in vitro analyses revealed that Rre1 phosphorylation level, DNA binding activity and adjacent gene transcription increased in response to heat stress. These responses were much diminished in a knock-out mutant of Hik34, a previously identified heat shock regulator. Based on our results, we propose Hik34-Rre1 is the heat shock-responsive signaling module that positively regulates major chaperone and other genes in cyanobacteria.
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, 4259-R1-29 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.|Graduate School of Interdisciplinary Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-29, Midori-ku, Yokohama, 226-8503, Japan.
authors.forename: Ikki
authors.initials: I
authors.lastname: Kobayashi
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: NODAI Genome Research Center, Tokyo University of Agriculture, Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kanesaki
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, 4259-R1-29 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Shimada
authors.affiliation: Department of Bioscience, Tokyo University of Agriculture, Sakuragaoka, Setagaya-ku, Tokyo, 156-8502, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yoshikawa
authors.affiliation: Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, 4259-R1-29 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan.
authors.forename: Kan
authors.identifier: 0000-0001-7560-7884
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D047369:Chromatin Immunoprecipitation; D000458:Cyanobacteria / Q000235:genetics; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D018869:Heat-Shock Response / Q000502:physiology*; D000071677:Histidine Kinase / Q000378:metabolism; D006358:Hot Temperature; D008027:Light; D018832:Molecular Chaperones / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D012808:Sigma Factor / Q000378:metabolism; D015398:Signal Transduction; D046940:Synechococcus / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D018832:Molecular Chaperones; D012808:Sigma Factor; D011494:Protein Kinases; D000071677:Histidine Kinase