RRC ID 35658
Author Yamamoto S, Mitobe J, Ishikawa T, Wai SN, Ohnishi M, Watanabe H, Izumiya H.
Title Regulation of natural competence by the orphan two-component system sensor kinase ChiS involves a non-canonical transmembrane regulator in Vibrio cholerae.
Journal Mol Microbiol
Abstract In Vibrio cholerae, 41 chitin-inducible genes, including the genes involved in natural competence for DNA uptake, are governed by the orphan two-component system (TCS) sensor kinase ChiS. However, the mechanism by which ChiS controls the expression of these genes is currently unknown. Here, we report the involvement of a novel transcription factor termed 'TfoS' in this process. TfoS is a transmembrane protein that contains a large periplasmic domain and a cytoplasmic AraC-type DNA-binding domain, but lacks TCS signature domains. Inactivation of tfoS abolished natural competence as well as transcription of the tfoR gene encoding a chitin-induced small RNA essential for competence gene expression. A TfoS fragment containing the DNA-binding domain specifically bound to and activated transcription from the tfoR promoter. Intracellular TfoS levels were unaffected by disruption of chiS and coexpression of TfoS and ChiS in Escherichia coli recovered transcription of the chromosomally integrated tfoR::lacZ gene, suggesting that TfoS is post-translationally modulated by ChiS during transcriptional activation; however, this regulation persisted when the canonical phosphorelay residues of ChiS were mutated. The results presented here suggest that ChiS operates a chitin-induced non-canonical signal transduction cascade through TfoS, leading to transcriptional activation of tfoR.
Volume 91(2)
Pages 326-47
Published 2014-1-1
DOI 10.1111/mmi.12462
PMID 24236404
MeSH Bacterial Proteins / genetics Bacterial Proteins / metabolism* Chitin / metabolism* Gene Expression Regulation, Bacterial Molecular Sequence Data Signal Transduction Vibrio cholerae / metabolism* Vibrio cholerae / physiology*
IF 3.418
Times Cited 32
WOS Category MICROBIOLOGY BIOCHEMISTRY & MOLECULAR BIOLOGY
Resource
Prokaryotes E. coli pJP5608 pWM91