Roles of cADPR and NAADP in pancreatic beta cell signaling

Since the discovery of the pyridine nucleotide metabolites Ca²⁺ mobilizing messengers cyclic ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP), they have been demonstrated to function as Ca²⁺ signaling messengers in a wide range of cell types. In this review, I will briefly summarize the roles of cADPR and NAADP in the physiological process of stimulus-secretion coupling in pancreatic β cells. I am also going to outline the current breadth of knowledge regarding intracellular Ca²⁺ stores and Ca²⁺ channels targeted by cADPR and NAADP, as well as the biogenesis of these Ca²⁺ signaling messengers. I focused on receptor-mediated Ca²⁺ signaling in mediating the effects of GLP-1 and insulin in pancreatic β cells. A better grasp in the roles of these signaling messengers will assist in our understanding of Ca²⁺ signaling as well as pathophysiology.