PMID:15327941

Citation	Barak, R and Eisenbach, M (2004) Co-regulation of acetylation and phosphorylation of CheY, a response regulator in chemotaxis of Escherichia coli. J. Mol. Biol. 342:375-81
Abstract	CheY, a response regulator of the chemotaxis system in Escherichia coli, can be activated by either phosphorylation or acetylation to generate clockwise rotation of the flagellar motor. Both covalent modifications are involved in chemotaxis, but the function of the latter remains obscure. To understand why two different modifications apparently activate the same function of CheY, we studied the effect that each modification exerts on the other. The phosphodonors of CheY, the histidine kinase CheA and acetyl phosphate, each strongly inhibited both the autoacetylation of the acetylating enzyme, acetyl-CoA synthetase (Acs), and the acetylation of CheY. CheZ, the enzyme that enhances CheY dephosphorylation, had the opposite effect and enhanced Acs autoacetylation and CheY acetylation. These effects of the phosphodonors and CheZ were not caused by their respective activities. Rather, they were caused by their interactions with Acs and, possibly, with CheY. In addition, the presence of Acs elevated the phosphorylation levels of both CheA and CheY, and acetate repressed this stimulation. These observations suggest that CheY phosphorylation and acetylation are linked and co-regulated. We propose that the physiological role of these mutual effects is at two levels: linking chemotaxis to the metabolic state of the cell, and serving as a tuning mechanism that compensates for cell-to-cell variations in the concentrations of CheA and CheZ.
Links	PubMed Online version:10.1016/j.jmb.2004.07.021
Keywords	Acetylation; Bacterial Proteins/metabolism; Chemotaxis/physiology; Coenzyme A Ligases/metabolism; Escherichia coli/metabolism; Membrane Proteins/metabolism; Phosphoric Acid Esters/metabolism; Phosphorylation
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
ECOLI:CHEA		GO:0031400: negative regulation of protein modification process	ECO:0000314:		P		Figure 1A. Presence of CheA negatively regulates acetylation of CheY.	complete CACAO 5148
ECOLI:CHEA	involved_in	GO:0031400: negative regulation of protein modification process	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete

References

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