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Updated: Dec 23, 2025
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Imaging G-protein Coupled Receptor GPCR-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum
Published on: September 20, 2011
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ATP Binding as a Key Target for Control of the Chemotaxis Kinase
Se-Young Jun1, Wenlin Pan1, Gerald L Hazelbauer2
1Department of Biochemistry, University of Missouri, Columbia, Missouri, USA.
Journal of Bacteriology
|April 29, 2020
Summary
Chemoreceptors control bacterial chemotaxis by regulating ATP binding to the CheA kinase. This ordered kinetic mechanism, where ATP must bind first, explains how signaling complexes modulate kinase activity.
Area of Science:
- Biochemistry
- Molecular Biology
- Microbiology
Background:
- Bacterial chemotaxis relies on chemoreceptors modulating histidine kinase CheA activity.
- CheA autophosphorylation is crucial, but the precise control mechanism remains unclear.
Purpose of the Study:
- Investigate the kinetic mechanism of CheA autophosphorylation.
- Determine how receptor-mediated control influences enzyme activity.
Main Methods:
- Kinetic analysis of activated CheA in signaling complexes.
- Enzyme binding assays using non-hydrolyzable ATP analogs.
Main Results:
- CheA autophosphorylation follows an ordered sequential mechanism, with ATP binding as the essential first step.
- The CheA P1 domain binds only after ATP is bound, forming the active site.
- Chemoreceptors likely control kinase activity by regulating ATP binding to CheA.
Conclusions:
- The ordered kinetic mechanism of CheA provides the biochemical basis for receptor-mediated control.
- Regulation of ATP binding is the key mechanism by which chemoreceptors modulate CheA activity.
- Ordered mechanisms and ATP binding control are likely conserved in other two-component signaling systems.
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