title: The heat-inducible essential response regulator WalR positively regulates transcription of sigI, mreBH and lytE in Bacillus subtilis under heat stress.
abstract: The actin homolog MreBH governs cell morphogenesis of Bacillus subtilis through localization of the cell wall hydrolase LytE. The alternative sigma factor SigI of B. subtilis coordinately regulates transcription of mreBH and lytE. Transcription of sigI, mreBH and lytE is heat-inducible. The essential response regulator WalR (YycF) plays a key role in coordinating cell wall metabolism with cell proliferation. We now demonstrate that mreBH is a new member of the WalR regulon. We also found that WalR can positively and directly regulate sigI transcription under heat stress through a binding site located upstream of the σ(I) promoter of sigI. In addition, we found that a WalR binding site located upstream of the SigI binding site in the regulatory region of lytE is important for lytE expression under heat stress. Moreover, we found that walR is a new member of the heat shock stimulon of B. subtilis. WalR appears to coordinately and positively regulate transcription of sigI, mreBH and lytE under heat stress. Finally, our work shows for the first time that WalR can stimulate activities of σ(I) promoters under heat stress.
authors.affiliation: Institute of Biochemistry and Molecular Biology, School of Life Science, National Yang-Ming University, Taipei 112, Taiwan, ROC. Electronic address: Mengyaw1018@yahoo.com.tw.
authors.forename: Wan-Zhen
authors.initials: WZ
authors.lastname: Huang
authors.forename: Jyun-Jhih
authors.initials: JJ
authors.lastname: Wang
authors.forename: Hui-Ju
authors.initials: HJ
authors.lastname: Chen
authors.forename: Jung-Tze
authors.initials: JT
authors.lastname: Chen
authors.forename: Gwo-Chyuan
authors.initials: GC
authors.lastname: Shaw
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000528:radiation effects*; D006358:Hot Temperature; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000096:biosynthesis*; D018085:Regulon; D012808:Sigma Factor / Q000096:biosynthesis*; D014158:Transcription, Genetic / Q000528:radiation effects*
chemical_list: D001426:Bacterial Proteins; C422477:SigI protein, Bacillus subtilis; D012808:Sigma Factor; C119939:YycF protein, Bacteria; C112181:LytE protein, Bacillus subtilis; D009238:N-Acetylmuramoyl-L-alanine Amidase
keywords: Bacillus subtilis; Heat stress; WalR; lytE; mreBH; sigI