Document Detail


A phospho-signaling pathway controls the localization and activity of a protease complex critical for bacterial cell cycle progression.
MedLine Citation:
PMID:  16829582     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Temporally and spatially controlled master regulators drive the Caulobacter cell cycle by regulating the expression of >200 genes. Rapid clearance of the master regulator, CtrA, by the ClpXP protease is a critical event that enables the initiation of chromosome replication at specific times in the cell cycle. We show here that a previously unidentified single domain-response regulator, CpdR, when in the unphosphorylated state, binds to ClpXP and, thereby, causes its localization to the cell pole. We further show that ClpXP localization is required for CtrA proteolysis. When CpdR is phosphorylated, ClpXP is delocalized, and CtrA is not degraded. Both CtrA and CpdR are phosphorylated via the same CckA histidine kinase phospho-signaling pathway, providing a reinforcing mechanism that simultaneously activates CtrA and prevents its degradation by delocalizing the CpdR/ClpXP complex. In swarmer cells, CpdR is in the phosphorylated state, thus preventing ClpXP localization and CtrA degradation. As swarmer cells differentiate into stalked cells (G1/S transition), unphosphorylated CpdR accumulates and is localized to the stalked cell pole, where it enables ClpXP localization and CtrA proteolysis, allowing the initiation of DNA replication. Dynamic protease localization mediated by a phospho-signaling pathway is a novel mechanism to integrate spatial and temporal control of bacterial cell cycle progression.
Authors:
Antonio A Iniesta; Patrick T McGrath; Ann Reisenauer; Harley H McAdams; Lucy Shapiro
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2006-07-07
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  103     ISSN:  0027-8424     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  2006 Jul 
Date Detail:
Created Date:  2006-07-19     Completed Date:  2006-08-22     Revised Date:  2009-11-19    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  United States    
Other Details:
Languages:  eng     Pagination:  10935-40     Citation Subset:  IM    
Affiliation:
Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA.
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MeSH Terms
Descriptor/Qualifier:
Bacterial Proteins / genetics,  metabolism*
Caulobacter crescentus / cytology*,  genetics,  metabolism*
Cell Cycle*
Endopeptidases / genetics,  metabolism*
Phosphorus / metabolism*
Phosphorylation
Protein Binding
Protein Kinases / metabolism
Protein Transport
Signal Transduction*
Substrate Specificity
Grant Support
ID/Acronym/Agency:
GM32506/GM/NIGMS NIH HHS; T32 HG00044/HG/NHGRI NIH HHS
Chemical
Reg. No./Substance:
0/Bacterial Proteins; 7723-14-0/Phosphorus; EC 2.7.-/Protein Kinases; EC 2.7.3.-/protein-histidine kinase; EC 3.4.-/Endopeptidases
Comments/Corrections

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