FIGURE 23. Calcium signaling through G-protein-coupled receptors (GPCRs).

FIGURE 23

Calcium signaling through G-protein-coupled receptors (GPCRs). G-protein mediated activation of phospholipase C (PLC) catalyzes the conversion of phosphatidylinositol bisphosphate (PIP2) into diacylglycerol (DAG) and inositol triphosphate (IP3). IP3 binding to the endoplasmic reticulum (ER) IP3 receptor (IP3R) causes intracellular Ca2+ release from the ER. Activation of the IP3R triggers activation of plasma membrane Ca2+ channels, and Ca2+ influx dramatically raises the intracellular-free Ca2+ concentration (Ca2+-induced Ca2+ influx) to induce Ca2+-dependent cell signaling events and endothelial hyperpermeability. Excess intracellular free Ca2+ is transported into the ER by the ATP-driven sarco(endo)plasmic reticulum Ca2+ (SERCa) pump, or is internalized by mitochondria.

From: Chapter 5, Signaling Mechanisms in the Regulation of Endothelial Permeability

Cover of Regulation of Endothelial Barrier Function
Regulation of Endothelial Barrier Function.
Yuan SY, Rigor RR.
San Rafael (CA): Morgan & Claypool Life Sciences; 2010.
Copyright © 2011 by Morgan & Claypool Life Sciences.

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