Journal
JOURNAL OF BACTERIOLOGY
Volume 191, Issue 24, Pages 7417-7429Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/JB.00992-09
Keywords
-
Categories
Funding
- NIH [5R01GM082899]
Ask authors/readers for more resources
In Caulobacter crescentus, progression through the cell cycle is governed by the periodic activation and inactivation of the master regulator CtrA. Two phosphorelays, each initiating with the histidine kinase CckA, promote CtrA activation by driving its phosphorylation and by inactivating its proteolysis. Here, we examined whether the CckA phosphorelays also influence the downregulation of CtrA. We demonstrate that CckA is bifunctional, capable of acting as either a kinase or phosphatase to drive the activation or inactivation, respectively, of CtrA. By identifying mutations that uncouple these two activities, we show that CckA's phosphatase activity is important for downregulating CtrA prior to DNA replication initiation in vivo but that other phosphatases may exist. Our results demonstrate that cell cycle transitions in Caulobacter require and are likely driven by the toggling of CckA between its kinase and phosphatase states. More generally, our results emphasize how the bifunctional nature of histidine kinases can help switch cells between mutually exclusive states.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available