Characterization and regulation of atrial natriuretic peptide (ANP)-R1 receptors in the human neuroblastoma cell line NB-OK-1.
We characterized in membranes from the human neuroblastoma cell line NB-OK-1, an ANP-R1 receptor (Mr 130 kDa) for the atrial natriuretic peptide (ANP). This receptor recognized biologically active forms of ANP with high affinity but showed no affinity for truncated ANP forms. It was functional in that binding correlated with guanylate cyclase activation (a 2-fold increase in Vmax) with the following rank order of potency: rat ANP-(99-126) greater than human ANP-(99-126) greater than human ANP-(102-126) greater than porcine BNP (brain natriuretic peptide). The enzyme required free Mn2+ in addition to the Mn-GTP substrate (Km of about 0.3 mM for both basal and ANP-stimulated activity). In the presence of dithiothreitol, the dose-response curve of guanylate cyclase activation was shifted rightward by a factor of 30. ANP-R1 receptors were upregulated through protein synthesis in cells exposed to 1 mM carbamylcholine or 1 mM dibutyryl cyclic AMP for 8-24 h (ANP was ineffective).
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium.
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Delporte
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Poloczek
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Gossen
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Tastenoy
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Winand
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Christophe
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D003432:Cross-Linking Reagents; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D007457:Iodine Radioisotopes; D007700:Kinetics; D008345:Manganese / Q000378:metabolism; D020097:Natriuretic Peptide, Brain; D009363:Neoplasm Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009423:Nervous System Neoplasms / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D051381:Rats; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013552:Swine; D014407:Tumor Cells, Cultured
D003432:Cross-Linking Reagents; D007457:Iodine Radioisotopes; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D020097:Natriuretic Peptide, Brain; D008345:Manganese; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor