Hydrolase that metabolizes extracellular nucleotides, including ATP, GTP, UTP and CTP (PubMed:29717535). Limits mast cell and basophil responses during inflammation and during the chronic phases of allergic responses by eliminating the extracellular ATP that functions as signaling molecule and activates basophils and mast cells and induces the release of inflammatory cytokines. Metabolizes extracellular ATP in the lumen of the small intestine, and thereby prevents ATP-induced apoptosis of intestinal plasmacytoid dendritic cells (By similarity). Has also alkaline phosphodiesterase activity (PubMed:11342463). Hydrolytically removes 5'-nucleotides successively from the 3'-hydroxy termini of 3'-hydroxy-terminated oligonucleotides. a ribonucleoside 5'-triphosphate + H2O = a ribonucleoside 5'-phosphate + diphosphate + H(+) a 2'-deoxyribonucleoside 5'-triphosphate + H2O = a 2'-deoxyribonucleoside 5'-phosphate + diphosphate + H(+) Binds 2 zinc ions per subunit. Monomer and homodimer. Detected at the cell surface of basophils (PubMed:11342463). Detected at the apical plasma membrane of bile duct cells (PubMed:15072822). Located to the apical surface in intestinal and kidney epithelial cells. Secreted in serum, and in lumen of epithelial cells. Detected on bile ducts in liver, and in blood serum (at protein level) (PubMed:15072822). Detected in prostate and uterus (PubMed:9344668). Detected on basophils, but not neutrophils (PubMed:11342463). Up-regulated by stimulation by allergen or by cross-linking with IgE. The IgE-mediated activation is enhanced by tetradecanoyl phorbol acetate (TPA), a stimulator of the PKC pathway, and inhibited by the P13 kinase inhibitors, LY294002 and wortmannin. Up-regulated in invasive bile duct cancers. N-glycosylated. N-glycosylation is necessary for normal transport to the cell membrane, but is not the apical targeting signal. Belongs to the nucleotide pyrophosphatase/phosphodiesterase family.