FliW and FliS function independently to control cytoplasmic flagellin levels in Bacillus subtilis.

ABSTRACT: The cytoplasmic level of flagellin (called Hag) is homeostatically regulated in the Gram-positive bacterium Bacillus subtilis by a partner-switching mechanism between the protein FliW and either the Hag structural protein or CsrA, an RNA binding protein that represses hag translation. Here we show that FliW and the putative secretion chaperone FliS bind to Hag simultaneously but control Hag translation by different mechanisms. While FliW directly inhibits CsrA activity, FliS antagonizes CsrA indirectly by binding to Hag, enhancing Hag secretion, and depleting Hag in the cytoplasm to trigger the FliW partner switch. Consistent with a role for FliS in potentiating Hag secretion, the mutation of fliS crippled both motility and flagellar filament assembly, and both phenotypes could be partiall

SUBMITTER: Mukherjee S 

PROVIDER: S-EPMC3553831 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature