CD38, also known as ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase 1, is a Signal-anchor for type II membrane protein. CD38 is able to transform NAD+ to ADP-D-ribose and nicotinamide. It also can transform NADP+ to nicotinate-adenine dinucleotide phosphate and nicotinamide. CD38 is expressed at high levels in pancreas, liver, kidney, brain, testis, ovary, placenta, malignant lymphoma and neuroblastoma. Synthesizes the second messagers cyclic ADP-ribose and nicotinate-adenine dinucleotide phosphate, the former a second messenger for glucose-induced insulin secretion. Also has cADPr hydrolase activity. Also moonlights as a receptor in cells of the immune system.
