RRC ID 53801
Author Asai K, Ootsuji T, Obata K, Matsumoto T, Fujita Y, Sadaie Y.
Title Regulatory role of RsgI in sigI expression in Bacillus subtilis.
Journal Microbiology (Reading, Engl.)
Abstract The sigma gene, sigI, of Bacillus subtilis belongs to the group IV heat-shock response genes and has many orthologues in the bacterial phylum Firmicutes. The B. subtilis sigI gene is considered to constitute an operon with rsgI (regulation of sigI, formerly ykrI). As little is known about either the structure and function of the sigI-rsgI operon or the SigI regulons, the role of RsgI in heat-inducible transcription of the sigI-rsgI operon was investigated, using Northern analysis and a heat-stable beta-galactosidase reporter assay. Heat-inducible, SigI-dependent transcription of the sigI-rsgI operon was stimulated greatly by disrupting rsgI. Yeast two-hybrid analysis showed direct interaction between the N-terminal portion of the presumed RsgI protein and SigI. Without RsgI function, induction of transcription of the sigI-rsgI operon upon transient heat stress depended on dnaK activity. However, transcription of the operon was induced during growth at prolonged higher temperature even without DnaK function. Without RsgI function, sigI-rsgI operon transcription was induced after the end of growth independent of any temperature shift in a sporulation medium and toward the end of growth in a rich complex medium. Furthermore, glucose addition resulted in a strong suppression of sigI-rsgI transcription. Therefore it is hypothesized that transcription of the sigI-rsgI operon of B. subtilis is negatively regulated by the putative transmembrane protein RsgI, which moderates SigI's sensitivity to heat shock or nutritional stress.
Volume 153(Pt 1)
Pages 92-101
Published 2007-1
DOI 10.1099/mic.0.29239-0
PII 153/1/92
PMID 17185538
MeSH Bacillus subtilis / genetics* Bacterial Proteins / biosynthesis Bacterial Proteins / genetics* Base Sequence Down-Regulation* Heat-Shock Proteins / genetics* Heat-Shock Response Molecular Sequence Data Operon / genetics Promoter Regions, Genetic / genetics Sigma Factor / genetics* Transcription, Genetic
IF 1.922
Prokaryotes B. subtilis MBS614 MBS631 MBS632 MBS633 MBS634 MBS635 MBS636 MBS637 MBS638 MBS639 MBS640 MBS641