Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Monoclonal antibody RB13-6 recognizes a subset of rat brain glial precursor cells that are highly susceptible to malignant conversion by the carcinogen N-ethyl-N-nitrosourea. The corresponding cell surface antigen was identified as a membrane glycoprotein (gp130RB13-6) and purified by immunoaffinity chromatography from the tumorigenic neuroectodermal rat cell line BT4Ca. Sequencing of 5 endoproteinase-generated peptides of the purified antigen permitted the specific amplification of a cDNA fragment by reverse transcription-polymerase chain reaction and subsequent isolation of the complete coding sequence from a fetal rat brain cDNA library. The derived amino acid sequence indicates that the RB13-6 antigen is related to the human and murine plasma cell membrane protein PC-1, a nucleotide pyrophosphatase/alkaline phosphodiesterase and ectoprotein kinase. Similarly, purified gp130RB13-6 possesses 5'-nucleotidase activity that can be inhibited with EDTA. Different from PC-1, gp130RB13-6 isolated from BT4Ca cells is not a disulfide-linked dimer and contains an RGD-tripeptide sequence which, together with other structural features, suggests a possible function in cell adhesion and its subversion in malignant phenotypes.
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PMID:Affinity purification and cDNA cloning of rat neural differentiation and tumor cell surface antigen gp130RB13-6 reveals relationship to human and murine PC-1. 773 Mar 66

The human leukocyte surface Ag CD38 was recently identified as a nicotinamide adenine dinucleotide (NAD)(+)-glycohydrolase ecto-enzyme, degrading NAD into nicotinamide and ADP-ribose. We show here that expression of CD38 is increased in the Jurkat T cell line after treatment with agents that augment intracellular cAMP, with the permeant cAMP analogue dibutyryl-cAMP (db-cAMP), and also with PMA, which activates protein kinase C. Treatment of human PBL T cells with db-cAMP or submitogenic doses of PMA also increased CD38 expression. Two other nucleotide-hydrolyzing activities were induced on the T cell surface concomitantly with CD38: the human PC-1 molecule, a nucleotide phosphodiesterase/pyrophosphatase that produces AMP from NAD or ADP-ribose, and a nucleotidase that produces adenosine from AMP, but which may be distinct from the CD73 5'-nucleotidase. All three enzymes were up-regulated after stimulation of human peripheral blood T cells with PHA. The coordinated regulation of these ecto-enzymes suggested that, besides a possible signaling function, they may recycle extracellular NAD by degrading it to adenosine and nicotinamide, which can be taken up by cells. In support of this hypothesis, db-cAMP-treated Jurkat cells could degrade extracellular NAD for de novo synthesis of purines, while untreated cells could not. Activated lymphocytes are often located in tissues in which cell death is common. It is suggested that the coordinated expression of these enzymes may allow activated T cells to re-use NAD and nucleotides from dead cells.
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PMID:Coordinated regulation in human T cells of nucleotide-hydrolyzing ecto-enzymatic activities, including CD38 and PC-1. Possible role in the recycling of nicotinamide adenine dinucleotide metabolites. 875 17