Document Detail


The chemotaxis response regulator CheY can catalyze its own acetylation.
MedLine Citation:
PMID:  16630631     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
One of the processes by which CheY, the excitatory response regulator of chemotaxis in Escherichia coli, can be activated to generate clockwise flagellar rotation is by acetyl-CoA synthetase (Acs)-mediated acetylation. Deletion of Acs results in defective chemotaxis, indicating the involvement of Acs-mediated acetylation in chemotaxis. To investigate whether Acs is the sole acetylating agent of CheY, we purified the latter from a delta acs mutant. Mass spectrometry analysis revealed that this protein is partially acetylated in spite of the absence of Acs, suggesting that CheY can be post-translationally acetylated in vivo by additional means. Using [14C]AcCoA in the absence of Acs, we demonstrated that one of these means is autoacetylation, with AcCoA serving as an acetyl donor and with a rate similar to that of Acs-mediated acetylation. Biochemical characterization of autoacetylated CheY and mass spectrometry analysis of its tryptic digests revealed that its acetylated lysine residues are those found in CheY acetylated by Acs, but the acetylation-level distribution among the acetylation sites was different. Like CheY acetylated by Acs, autoacetylated CheY could be deacetylated by Acs. Also similarly to the case of Acs-mediated acetylation, the phosphodonors of CheY, CheA and acetyl phosphate, each inhibited the autoacetylation of CheY, whereas the phosphatase of CheY, CheZ, enhanced it. A reduced AcCoA level interfered with chemotaxis to repellents, suggesting that CheY autoacetylation may be involved in chemotaxis of E. coli. Interestingly, this interference was restricted to repellent addition and was not observed with attractant removal, thus endorsing our earlier suggestion that the signaling pathway triggered by repellent addition is not identical to that triggered by attractant removal.
Authors:
Rina Barak; Jianshe Yan; Alla Shainskaya; Michael Eisenbach
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-03-31
Journal Detail:
Title:  Journal of molecular biology     Volume:  359     ISSN:  0022-2836     ISO Abbreviation:  J. Mol. Biol.     Publication Date:  2006 Jun 
Date Detail:
Created Date:  2006-05-10     Completed Date:  2006-07-05     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985088R     Medline TA:  J Mol Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  251-65     Citation Subset:  IM    
Affiliation:
Department of Biological Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel.
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MeSH Terms
Descriptor/Qualifier:
Acetyl Coenzyme A / metabolism
Acetylation
Adenosine Triphosphate / metabolism
Bacterial Proteins / chemistry*,  genetics,  metabolism*
Chemotaxis*
Citric Acid Cycle
Coenzyme A Ligases / genetics,  metabolism*
Escherichia coli / metabolism*
Escherichia coli Proteins / chemistry*,  genetics,  metabolism*
Membrane Proteins / chemistry*,  genetics,  metabolism*
Molecular Weight
Chemical
Reg. No./Substance:
0/Bacterial Proteins; 0/Escherichia coli Proteins; 0/Membrane Proteins; 0/methyl-accepting chemotaxis proteins; 56-65-5/Adenosine Triphosphate; 72-89-9/Acetyl Coenzyme A; EC 6.2.1.-/Coenzyme A Ligases; EC 6.2.1.13/acetate-CoA ligase (ADP-forming)

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


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