title: Transcriptional regulation under pressure conditions by RNA polymerase sigma54 factor with a two-component regulatory system in Shewanella violacea.
abstract: Deep-sea bacteria have unique systems for gene and protein expression controlled by hydrostatic pressure. One of the sigma factors, sigma54, was found to play an important role in pressure-regulated transcription in a deep-sea piezophilic bacterium, Shewanella violacea. A glutamine synthetase gene (glnA) has been targeted as a model for the pressure-regulated promoter to investigate transcriptional regulation by the sigma54 factor. Recognition sites for sigma54 and sigma70 factors were observed at an upstream region of the glnA, and NtrC-binding sites were also identified at the same region. Primer extension analyses revealed that the transcription initiation sites of both promoters were determined and that transcription from the sigma54 site was regulated by elevated pressure. The sigma54 promoter is known to be activated by a two-component signal transduction system, the NtrB-NtrC phosphorylation relay. Our results suggested that this system might be regulated by deep-sea conditions and that the gene expression controlled by the sigma54 promoter was actually regulated by pressure. We propose a possible model of the molecular mechanisms for pressure-regulated transcription.
authors.affiliation: Department of Chemistry and Environmental Technology, School of Engineering, Kinki University, Higashi-Hiroshima, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Nakasone
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ikegami
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kawano
authors.forename: Chiaki
authors.initials: C
authors.lastname: Kato
authors.forename: Ron
authors.initials: R
authors.lastname: Usami
authors.forename: Koki
authors.initials: K
authors.lastname: Horikoshi
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D005798:Genes, Bacterial; D005974:Glutamate-Ammonia Ligase / Q000235:genetics; D006874:Hydrostatic Pressure; D008954:Models, Biological; D008969:Molecular Sequence Data; D051922:PII Nitrogen Regulatory Proteins; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000378:metabolism; D051877:RNA Polymerase Sigma 54; D020592:Shewanella / Q000235:genetics* / Q000378:metabolism*; D012808:Sigma Factor / Q000378:metabolism*; D015534:Trans-Activators; D014157:Transcription Factors; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D051922:PII Nitrogen Regulatory Proteins; D012808:Sigma Factor; D015534:Trans-Activators; D014157:Transcription Factors; D011494:Protein Kinases; C055699:protein kinase-phosphatase NTRB; D012321:DNA-Directed RNA Polymerases; D051877:RNA Polymerase Sigma 54; D010749:Phosphoprotein Phosphatases; C081173:glutamine synthetase I; D005974:Glutamate-Ammonia Ligase