Main distribution, biochemical properties, and physiological roles of mammalian E-NTPDases 1, 2, 3, and 8

ENTPDaseMain distributionBiochemical propertiesMain physiological functionsReferences
NTPDase1/CD39Immune system cells (monocyte/macrophages, microglia, T and B cells, neutrophils, leukocytes), endothelial and smooth muscle cellsThere is no clear preference between Ca2+ and Mg2+. Lower activity at acidic pH. Hydrolyzes ATP and ADP about equally well. Km for ATP: 17 μMPrevention of thrombosis. Modulation of vascular tone. Modulation of vascular inflammation and immune responses. Neuroprotection and cardioprotection.[2, 5, 7, 11, 12, 28]
NTPDase2/CD39L1Cells of the vascular adventitia, microvascular pericytes, subendocardial space, portal fibroblasts, astrocytes, taste buds, and neural precursor cellsThere is no clear preference between Ca2+ and Mg2+. High preference for ATP over ADP (preferential ecto-ATPase). Km for ATP: 70 μMRegulation of vascular hemostasis. Involvement in controlling neurogenesis and neural differentiation. Role in taste information transmission from taste buds to gustatory nerves. Modulation of portal fibroblast proliferation.[2, 5, 7, 1417, 28]
NTPDase3/CD39L3Hypocretinergic neurons, sensory neurons, islets of Langerhans, and renal and reproductive epitheliaPreference for Ca2+ and ATP over ADP. Km for ATP: 75 μMModulation of purinergic neurotransmission, regulation of nociceptive circuits, involvement in the development of circadian rhythms in the hypothalamus, and role in energy metabolism.[2, 5, 7, 19, 20]
NTPDase8/Liver canalicular ecto-ATPaseBile canaliculi, intestinal, and renal epitheliaPreference for Ca2+ and ATP over ADP. Km for ATP: 81 μMRegulation of the inflammatory response in intestinal diseases.[2, 5, 8, 22]

ENTPDase: ectonucleoside triphosphate diphosphohydrolase; ADP: adenosine diphosphate; ATP: adenosine triphosphate; CD39: cluster of differentiation 39