ID 2.4.99.20 DE 2'-phospho-ADP-ribosyl cyclase/2'-phospho-cyclic-ADP-ribose transferase. AN diphosphopyridine nucleosidase. CA NADP(+) + nicotinate = nicotinamide + nicotinate-adenine dinucleotide CA phosphate. CC -!- This multiunctional enzyme catalyzes both the removal of nicotinamide CC from NADP(+), forming 2'-phospho-cyclic ADP-ribose, and the addition CC of nicotinate to the cyclic product, forming NAADP(+), a calcium CC messenger that can mobilize intracellular Ca(2+) stores and activate CC Ca(2+) influx to regulate a wide range of physiological processes. CC -!- In addition, the enzyme also catalyzes EC 3.2.2.6. DR P28907, CD38_HUMAN ; Q5VAN0, CD38_MACFA ; P56528, CD38_MOUSE ; DR Q9MZ03, CD38_RABIT ; Q64244, CD38_RAT ; P29241, NADA_APLCA ; DR Q27312, NADA_APLKU ; //