Stimulus perception and two-component signal transduction within the regulatory network of cell envelope stress response in Bacillus subtilis

• Applicant: Professor Dr. Thorsten Mascher
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2004 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5433816

A permanent and sensitive monitoring of environmental conditions is a prerequisite for the survival of bacteria living in a complex habitat such as the soil ecosystem. Two-component signal transduction is a ubiquitously distributed mechanism to sense parameters of the environment (input) and induce appropriate cellular responses as a result of changes thereof (output). We have recently identified a novel signal transducing mechanism in the cell wall stress response of Bacillus subtilis, mediated by intram embrane sensing histidine kinases. These proteins lack an extracytoplasmic sensing domain, and presumably monitor cell envelope integrity directly at the membrane interface. The first example of this protein family, LiaS of B. subtilis, senses perturbations of the lipid II cycle, a crucial step for cell wall homeostasis. Here, we propose the investigation of the corresponding LiaRS two-component system, the key regulator of a late stationary phase signalling cascade. We will focus on three aspects of its signal transduction: First, we want to investigate the intramembrane sensing mechanism of the histidine kinase LiaS. The second part will address the biological function of the identified LiaRStarget genes. Three members of this regulon encode putative transcriptional regulators (one alternative s factor and two response regulators as part of two-component systems). Therefore, the subject of the third part of this proposal will be the identification of their target genes, in vivo and in vitro.

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Participating Person: Professor Dr. Anthony Wilkinson