Related Experiment Video
Updated: Sep 27, 2026

Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum
Published on: September 20, 2011
Selective interaction of the C2 domains of phospholipase C-beta1 and -beta2 with activated Galphaq subunits: an
T Wang1, S Pentyala, J T Elliott
1Department of Physiology and Biophysics, State University of New York, Stony Brook, NY 11794-8661, USA.
Abstract:
Phospholipase C (PLC)-beta1 and PLC-beta2 are regulated by the Gq family of heterotrimeric G proteins and contain C2 domains. These domains are Ca2+-binding modules that serve as membrane-attachment motifs in a number of signal transduction proteins. To determine the role that C2 domains play in PLC-beta1 and PLC-beta2 function, we measured the binding of the isolated C2 domains to membrane bilayers. We found, unexpectedly, that these modules do not bind to membranes but they associate strongly and specifically to activated [guanosine 5'-[gamma-thio]triphosphate (GTP[gammaS])-bound] Galphaq subunits. The C2 domain of PLC-beta1 effectively suppressed the activation of the intact isozyme by Galphaq(GTP[gammaS]), indicating that the C2-Galphaq interaction may be physiologically relevant. C2 affinity for Galphaq(GTP[gammaS]) was reduced when Galphaq was deactivated to the GDP-bound state. Binding to activated Galphai1 subunits or to Gbetagamma subunits was not detected. Also, Galphaq(GTP[gammaS]) failed to associate with the C2 domain of PLC-delta, an isozyme that is not activated by Galphaq. These results indicate that the C2 domains of PLC-beta1 and PLC-beta2 provide a surface to which Galphaq subunits can dock, leading to activation of the native protein.
More Related Videos
07:41A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators
Published on: February 20, 2018
12:27A Pipeline to Investigate the Structures and Signaling Pathways of Sphingosine 1-Phosphate Receptors
Published on: June 8, 2022
Related Concept Videos
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Amplifying Signals via Second Messengers
Amplifying Signals via Enzymatic Cascade
Activation and Inactivation of G Proteins
GPCRs Regulate Adenylyl Cylase Activity
Two...
IP3/DAG Signaling Pathway