Controlling calcium entry.

Ca(2+) enters cells through an assortment of Ca(2+)-permeable channels that respond to different stimuli and couple to different cellular responses. Several different Ca(2+) entry pathways can be activated by receptors that stimulate phospholipase C (PLC). Both limbs of this signaling pathway (IP(3) and diacylglycerol), PLC itself, and its substrate (PIP(2)) contribute to the coordinate regulation of these Ca(2+) entry pathways.