HUMAN LYMPHOCYTE ANTIGEN CD38 CATALYZES THE PRODUCTION OF CYCLIC ADP-RIBOSE

The human lymphocyte antigen CD38 has been shown to share sequence hom ology with ADP-ribosyl cyclase, the enzyme that catalyzes the conversi on of NAD(+) to cyclic ADP-ribose (cADPR), a potent Ca2+-mobilizing ag ent. In this study COSl cells from African Green Monkey kidney were tr ansiently transfected with CD38 cDNA, inducing expression of authentic CD38 on the cell surface. We demonstrate that CD38 expressed in this manner can convert NAD(+) to cADPR in the extracellular medium as asse ssed by Ca2+ release from sea-urchin egg microsomes.