In vivo phosphorylation patterns of key stressosome proteins define a second feedback loop that limits activation of Bacillus subtilis σB.

ABSTRACT: The Bacillus subtilis stressosome is a 1.8 MDa complex that orchestrates activation of the σ(B) transcription factor by environmental stress. The complex comprises members of the RsbR co-antagonist family and the RsbS antagonist, which together form an icosahedral core that sequesters the RsbT serine-threonine kinase. Phosphorylation of this core by RsbT is associated with RsbT release, which activates downstream signalling. RsbRA, the prototype co-antagonist, is phosphorylated on T171 and T205 in vitro. In unstressed cells T171 is already phosphorylated; this is a prerequisite but not the trigger for activation, which correlates with stress-induced phosphorylation of RsbS on S59. In contrast, phosphorylation of RsbRA T205 has not been detected in vivo. Here we find (i) RsbRA is additional

SUBMITTER: Eymann C 

PROVIDER: S-EPMC3206960 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature