Description
Rhodospirillum centenum, an alpha-proteobacterium that transitions between multiple cellular states allowing this species to colonize a variety of environments. The hypothesized phosphorelay pathway DivK --|Cyd2 <--> ChpT --> CtrA is known to be genetically conserved in alpha-proteobacteria including such well-known species as Caulobacter cresentus and Sphingomonas melonis. In R. centenum, this phosphorelay is hypothesized to form a signal transduction system that affects differentiation into the swarm, swim, or cyst cell states. CtrA is a transcriptional activator that has been shown to enhance swarming and swimming motility while hindering encystment when cells are deprived of nutrients. We hypothesize that CtrA activity is directly regulated by the phosphotransferase protein ChpT. Our analysis of a chpT mutant strain suggests that the ChpT protein activates CtrA through phosphorylation so that cells choose to become motile, rather than encyst, in response to starvation.
Fight or Flight? The role of ChpT phosphotransferase in R. centenum motility and encystment.
Rhodospirillum centenum, an alpha-proteobacterium that transitions between multiple cellular states allowing this species to colonize a variety of environments. The hypothesized phosphorelay pathway DivK --|Cyd2 <--> ChpT --> CtrA is known to be genetically conserved in alpha-proteobacteria including such well-known species as Caulobacter cresentus and Sphingomonas melonis. In R. centenum, this phosphorelay is hypothesized to form a signal transduction system that affects differentiation into the swarm, swim, or cyst cell states. CtrA is a transcriptional activator that has been shown to enhance swarming and swimming motility while hindering encystment when cells are deprived of nutrients. We hypothesize that CtrA activity is directly regulated by the phosphotransferase protein ChpT. Our analysis of a chpT mutant strain suggests that the ChpT protein activates CtrA through phosphorylation so that cells choose to become motile, rather than encyst, in response to starvation.