Ca2+ signals initiate at immobile IP3 receptors adjacent to ER-plasma membrane junctions

Abstract

IP3 receptors mediate Ca2+ release from the endoplasmic reticulum. Here the authors show that only a small fraction of IP3 receptors initiate Ca2+ signals; these immobile IP3 receptors adjacent to the plasma membrane are optimally placed to control STIM1-dependent Ca2+ entry.