REGULATION OF CELLULAR CALCIUM THROUGH SIGNALING CROSS-TALK INVOLVES AN INTRICATE INTERPLAY BETWEEN THE ACTIONS OF RECEPTORS, G-PROTEINS, AND 2ND-MESSENGERS

Various external stimuli regulate cellular Ca2+ fluxes, Information fr om these stimuli is transmitted to the cell interior by signal transdu cing systems that involve interactions between receptors, G-proteins, and enzymes that generate second messengers. The possible mechanisms b y which ''cross-talk'' within and between these second messenger-gener ating systems provides an intricate molecular avenue for fine modulati on of intracellular Ca2+ are reviewed.