Mutually repressing repressor functions and multi-layered cellular heterogeneity regulate the bistable Salmonella fliC census.

ABSTRACT: Bistable flagellar and virulence gene expression generates specialized Salmonella subpopulations with distinct functions. Repressing flagellar genes allows Salmonella to evade caspase-1 mediated host defenses and enhances systemic colonization. By definition, bistability arises when intermediate states of gene expression are rendered unstable by the underlying genetic circuitry. We demonstrate sustained bistable fliC expression in virulent Salmonella 14028 and document dynamic control of the distribution, or single-cell census, of flagellar gene expression by the mutually repressing repressors YdiV and FliZ. YdiV partitions cells into the fliC-OFF subpopulation, while FliZ partitions cells into the fliC-HIGH subpopulation at late time points during growth. Bistability of ΔfliZ populations

SUBMITTER: Stewart MK 

PROVIDER: S-EPMC4262692 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature