Abstract
Stimulation of cell-surface receptors that couple to phospholipase C to generate the second messenger inositol trisphosphate often evokes repetitive oscillations in cytosolic Ca(2+) . Signalling information is encoded in both the amplitude and frequency of the Ca(2+) spikes. Recent studies have revealed that the spatial profile of the oscillation also imparts signalling power; Ca(2+) microdomains near store-operated CRAC channels in the plasma membrane and inositol trisphosphate-gated channels in the endoplasmic reticulum both signal to distinct downstream targets. Spatial profiling therefore increases the transduction power of the universal oscillatory cytosolic Ca(2+) signal.