Related Experiment Video
Updated: Jun 5, 2026

A Kinetic Fluorescence-based Ca2+ Mobilization Assay to Identify G Protein-coupled Receptor Agonists, Antagonists, and Allosteric Modulators
Published on: February 20, 2018
Specificity of G(q) and G(11) Protein Signaling in Vascular Myocytes
1Jean Mironneau and Nathalie Macrez are at the Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS ESA 5017, Université de Bordeaux II, Bordeaux, France.
Abstract:
The molecular diversity of receptors and the capability of these receptors to activate multiple types of G proteins theoretically allow the transmission of signals through multiple effector pathways. In functional experiments, however, the number of possibilities may be strongly reduced. We have recently reported that in vascular myocytes, α(1)-adrenoceptors activate two G proteins composed of α(q)/β(1)/γ(3) and α(11)/β(3)/γ(2) subunits, leading to increase in cytoplasmic [Ca(2+)](i) concentration. Only the α(q) subunit transduces the signal to a phospholipase C-β, which hydrolyzes phosphatidylinositol 4,5-bisphosphate to generate inositol 1,4,5-trisphosphate and the subsequent release of Ca(2+) from the intracellular store. In contrast, the α(11) subunit activates Ca(2+) entry through a nonspecific cation channel in the presence of increased [Ca(2+)](i) level. These coupling mechanisms reveal the distinct participation of G(q) and G(11) in the regulation of vascular contractility. Specific G(q)- or G(11)-activated pathways should be taken into account to understand the various contraction profiles induced by different vasoconstrictors.
More Related Videos
11:02Exploring Arterial Smooth Muscle Kv7 Potassium Channel Function using Patch Clamp Electrophysiology and Pressure Myography
Published on: September 14, 2012
08:28Isolation of Primary Patient-specific Aortic Smooth Muscle Cells and Semiquantitative Real-time Contraction Measurements In Vitro
Published on: February 15, 2022
Related Concept Videos
Activation and Inactivation of G Proteins
G-Protein Gated Ion Channels
Sensory organs,...
IP3/DAG Signaling Pathway
G-protein Coupled Receptors
G-protein Coupled Receptors
GPCRs Regulate Adenylyl Cylase Activity
Two...