Document Detail

Regulated proteolysis of a transcription factor complex is critical to cell cycle progression in Caulobacter crescentus.
MedLine Citation:
PMID:  23368090     Owner:  NLM     Status:  MEDLINE    
Cell cycle transitions are often triggered by the proteolysis of key regulatory proteins. In Caulobacter crescentus, the G1-S transition involves the degradation of an essential DNA-binding response regulator, CtrA, by the ClpXP protease. Here, we show that another critical cell cycle regulator, SciP, is also degraded during the G1-S transition, but by the Lon protease. SciP is a small protein that binds directly to CtrA and prevents it from activating target genes during G1. We demonstrate that SciP must be degraded during the G1-S transition so that cells can properly activate CtrA-dependent genes following DNA replication initiation and the reaccumulation of CtrA. These results indicate that like CtrA, SciP levels are tightly regulated during the Caulobacter cell cycle. In addition, we show that formation of a complex between CtrA and SciP at target promoters protects both proteins from their respective proteases. Degradation of either protein thus helps trigger the destruction of the other, facilitating a cooperative disassembly of the complex. Collectively, our results indicate that ClpXP and Lon each degrade an important cell cycle regulator, helping to trigger the onset of S phase and prepare cells for the subsequent programmes of gene expression critical to polar morphogenesis and cell division.
Kasia G Gora; Amber Cantin; Matthew Wohlever; Kamal K Joshi; Barrett S Perchuk; Peter Chien; Michael T Laub
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2013-02-25
Journal Detail:
Title:  Molecular microbiology     Volume:  87     ISSN:  1365-2958     ISO Abbreviation:  Mol. Microbiol.     Publication Date:  2013 Mar 
Date Detail:
Created Date:  2013-03-13     Completed Date:  2013-08-26     Revised Date:  2014-02-04    
Medline Journal Info:
Nlm Unique ID:  8712028     Medline TA:  Mol Microbiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  1277-89     Citation Subset:  IM    
Copyright Information:
© 2013 Blackwell Publishing Ltd.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Caulobacter crescentus / cytology,  genetics,  growth & development,  physiology*
Cell Cycle*
Gene Expression Regulation, Bacterial*
Octamer Transcription Factor-6 / metabolism*
Protease La / metabolism*
Grant Support
5R00GM084157/GM/NIGMS NIH HHS; 5R01GM082899/GM/NIGMS NIH HHS; R00 GM084157/GM/NIGMS NIH HHS; R01 GM082899/GM/NIGMS NIH HHS; //Howard Hughes Medical Institute
Reg. No./Substance:
132052-52-9/Octamer Transcription Factor-6; EC La

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Cardiovascular genomics.
Next Document:  Primary hepatocyte cultures as prominent in vitro tools to study hepatic drug transporters.