z-logo
Premium
The branched CcsA / CckA ‐ ChpT ‐ CtrA phosphorelay of S phingomonas melonis controls motility and biofilm formation
Author(s) -
FrancezCharlot Anne,
Kaczmarczyk Andreas,
Vorholt Julia A.
Publication year - 2015
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13011
Subject(s) - biology , biofilm , motility , microbiology and biotechnology , bacteria , genetics
Summary The CckA ‐ ChpT ‐ CtrA phosphorelay is central to the regulation of the cell cycle in C aulobacter crescentus . The three proteins are conserved in Alphaproteobacteria, but little is known about their roles in most members of this class. Here, we characterized the system in S phingomonas melonis . We found that the transcription factor CtrA is the master regulator of flagella synthesis genes, the hierarchical transcriptional organization of which is herein described. CtrA also regulates genes involved in exopolysaccharide synthesis and cyclic‐di‐ GMP signaling, and is important for biofilm formation. In addition, the ctrA mutant exhibits an aberrant morphology, suggesting a role for CtrA in cell division. An analysis of the regulation of CtrA indicates that the phosphorelay composed of CckA and ChpT is conserved and that the absence of the bifunctional kinase/phosphatase CckA apparently results in overactivation of CtrA through ChpT . Suppressors of this phenotype identified the hybrid histidine kinase CcsA . Phosphorelays initiated by CckA or CcsA were reconstituted in vitro , suggesting that in S . melonis , CtrA phosphorylation is controlled by a branched pathway upstream of ChpT . This study thus suggests that signals can directly converge at the level of ChpT phosphorylation through multiple hybrid kinases to coordinate a number of important physiological processes.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here