ExplorEnz: Search Results

2.4.99.20

Accepted name:

2′-phospho-ADP-ribosyl cyclase/2′-phospho-cyclic-ADP-ribose transferase

Reaction:

NADP⁺ + nicotinate = nicotinate-adenine dinucleotide phosphate + nicotinamide (overall reaction)
(1a) NADP⁺ = 2′-phospho-cyclic ADP-ribose + nicotinamide
(1b) 2′-phospho-cyclic ADP-ribose + nicotinate = nicotinate-adenine dinucleotide phosphate

Glossary:

2′-phospho-cyclic ADP-ribose = cADPRP
nicotinic acid-adenine dinucleotide phosphate = NAADP⁺

Other name(s):

diphosphopyridine nucleosidase (ambiguous); CD38 (gene name); BST1 (gene name)

Systematic name:

NADP⁺:nicotinate ADP-ribosyltransferase

Comments:

This multiunctional enzyme catalyses both the removal of nicotinamide from NADP⁺, forming 2′-phospho-cyclic ADP-ribose, and the addition of nicotinate to the cyclic product, forming NAADP⁺, a calcium messenger that can mobilize intracellular Ca²⁺ stores and activate Ca²⁺ influx to regulate a wide range of physiological processes. In addition, the enzyme also catalyses EC 3.2.2.6, ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase.

References:

1.	Chini, E.N., Chini, C.C., Kato, I., Takasawa, S. and Okamoto, H. CD38 is the major enzyme responsible for synthesis of nicotinic acid-adenine dinucleotide phosphate in mammalian tissues. Biochem. J. 362 (2002) 125–130. [PMID: 11829748]
2.	Moreschi, I., Bruzzone, S., Melone, L., De Flora, A. and Zocchi, E. NAADP⁺ synthesis from cADPRP and nicotinic acid by ADP-ribosyl cyclases. Biochem. Biophys. Res. Commun. 345 (2006) 573–580. [PMID: 16690024]

[EC 2.4.99.20 created 2014]