title: CD39 is an ecto-(Ca2+,Mg2+)-apyrase.
abstract: CD39, a 70- to 100-kDa molecule expressed primarily on activated lymphoid cells, was previously identified as a surface marker of Epstein Barr virus (EBV)-transformed B cells. In this report, we show that an ecto-(Ca2+,Mg2+)-apyrase activity is present on EBV-transformed B cells, but not on B or T lymphomas. The coincidence between CD39 expression and ecto-apyrase activity on immune cells suggests that CD39 may be an ecto-apyrase. This supposition is supported by the observation that the amino acid sequence of CD39 is significantly homologous to those of several newly identified nucleotide triphosphatases. Finally, we show that CD39 indeed has ecto-apyrase activity by expression in COS-7 cells.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: T F
authors.initials: TF
authors.lastname: Wang
authors.forename: G
authors.initials: G
authors.lastname: Guidotti
mesh_terms: D000251:Adenosine Triphosphatases; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D001081:Apyrase / Q000378:metabolism*; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D002522:Chlorocebus aethiops; D017931:DNA Primers / Q000737:chemistry; D005110:Extracellular Space / Q000201:enzymology; D006801:Humans; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000201:enzymology*; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D013379:Substrate Specificity; D014162:Transfection
chemical_list: D015703:Antigens, CD; D017931:DNA Primers; D000251:Adenosine Triphosphatases; D001081:Apyrase; C067869:CD39 antigen; D008274:Magnesium; D002118:Calcium