NTPDase2

NTPDase2 is a plasma-membrane ecto-ATPase that hydrolyzes extracellular ATP to ADP and thereby shapes purinergic signaling^[1]. Mechanistically, NTPDase2 differs from NTPDase1 because it preferentially hydrolyzes nucleoside triphosphates and permits ADP accumulation, whereas NTPDase1 limits ADP accumulation more efficiently^[2][3]. In adult mouse neurogenic niches, NTPDase2 scavenges mitogenic extracellular nucleoside triphosphates and controls neural progenitor cell proliferation^[4]. In taste buds, Entpd2 deletion causes extracellular ATP accumulation, receptor desensitization, and reduced taste-nerve transmission^[5]. In liver models, portal fibroblast NTPDase2 inhibits bile duct epithelial proliferation through blockade of P2Y activation, while biliary cirrhosis selectively down-regulates NTPDase2 expression^[6][7]. For experimental applications, ARL 67156 is not an effective inhibitor of NTPDase2, so NTPDase2 studies require isoform-aware enzymatic assays rather than assuming broad ecto-ATPase inhibition^[8].