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Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum
Published on: September 20, 2011
Transmembrane signaling in bacterial chemoreceptors
1Department of Chemistry and Biochemistry, University of Colorado, 80309-0215, Boulder, CO, USA. falke@colorado.edu
Trends in Biochemical Sciences
|April 11, 2001
Summary
Bacterial chemoreceptors use a piston-like helix movement to transmit signals across the cell membrane, enabling chemotaxis. This mechanism involves ligand binding and modulates histidine kinase activity for cellular response.
Area of Science:
- Microbiology
- Biochemistry
- Molecular Biology
Background:
- Bacterial chemoreceptors are crucial for chemotaxis, sensing environmental chemicals.
- They regulate noncovalently associated histidine kinases via transmembrane signaling.
- Ligand binding initiates a signal cascade from the external domain to the internal kinase.
Purpose of the Study:
- To investigate the mechanism of transmembrane signaling in bacterial chemoreceptors.
- To elucidate the conformational changes involved in signal transduction.
- To understand how chemical signals are converted into cellular responses.
Main Methods:
- Utilizing novel strategies to probe receptor conformational changes.
- Analyzing signaling helix movement across the receptor length (>350 Å).
- Examining evidence from periplasmic and transmembrane domains.
Main Results:
- Identified a subtle conformational signal within a signaling helix.
- Demonstrated a piston-type sliding motion of the signaling helix.
- Localized this motion to the periplasmic and transmembrane domains.
Conclusions:
- Bacterial chemoreceptor signaling involves a conserved piston-like helix movement.
- This conformational change is key to transmitting signals across the membrane.
- The mechanism explains how chemoreceptors modulate downstream kinase activity.
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