Regulatory Cohesion of Cell Cycle and Cell Differentiation through Interlinked Phosphorylation and Second Messenger Networks

In Caulobacter crescentus, phosphorylation of key regulators is coordinated with the second messenger cyclic di-GMP to drive cell-cycle progression and differentiation. The diguanylate cyclase PleD directs pole morphogenesis, while the c-di-GMP effector PopA initiates degradation of the replication...

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Bibliographic Details
Main Authors: Abel, Sören, Chien, Peter, Wassmann, Paul, Schirmer, Tilman, Kaever, Volkhard, Baker, Tania, Jenal, Urs, Laub, Michael T., Laub, Michael T
Other Authors: Massachusetts Institute of Technology. Department of Biology
Format: Article
Language:en_US
Published: Elsevier B.V. 2013
Online Access:http://hdl.handle.net/1721.1/82942
https://orcid.org/0000-0002-8288-7607
Description
Summary:In Caulobacter crescentus, phosphorylation of key regulators is coordinated with the second messenger cyclic di-GMP to drive cell-cycle progression and differentiation. The diguanylate cyclase PleD directs pole morphogenesis, while the c-di-GMP effector PopA initiates degradation of the replication inhibitor CtrA by the AAA+ protease ClpXP to license S phase entry. Here, we establish a direct link between PleD and PopA reliant on the phosphodiesterase PdeA and the diguanylate cyclase DgcB. PdeA antagonizes DgcB activity until the G1-S transition, when PdeA is degraded by the ClpXP protease. The unopposed DgcB activity, together with PleD activation, upshifts c-di-GMP to drive PopA-dependent CtrA degradation and S phase entry. PdeA degradation requires CpdR, a response regulator that delivers PdeA to the ClpXP protease in a phosphorylation-dependent manner. Thus, CpdR serves as a crucial link between phosphorylation pathways and c-di-GMP metabolism to mediate protein degradation events that irreversibly and coordinately drive bacterial cell-cycle progression and development.