Signaling through Ca2+ Microdomains from Store-Operated CRAC Channels.

Calcium (Ca2+) ion microdomains are subcellular regions of high Ca2+ concentration that develop rapidly near open Ca2+ channels in the plasma membrane or internal stores and generate local regions of high Ca2+ concentration. These microdomains are remarkably versatile in that they activate a range of responses that differ enormously in both their temporal and spatial profile. In this review, we describe how Ca2+ microdomains generated by store-operated calcium channels, a widespread and conserved Ca2+ entry pathway, stimulate different signaling pathways, and how the spatial extent of a Ca2+ microdomain can be influenced by Ca2+ ATPase pumps.