title: Identification of atrial natriuretic factor receptor of neuroblastoma N4TG1 cells: binding characteristics and photoaffinity labeling.
abstract: We have found specific receptors for atrial natriuretic factor (ANF) in cultured neuroblastoma cells (N4TG1) of peripheral ganglionic origin. Scatchard analysis of the displacement binding revealed noninteracting, single-class binding sites with a KD of 1 X 10(-10) M and a density (Bmax) of 110,000-150,000 sites/cell. The cell-bound 125I-ANF was displaced by unlabeled ANF in a dose-dependent manner. Hormones unrelated to ANF such as angiotensins, adrenocorticotropic hormone, or arginine vasopressin were ineffective in displacing the cell-bound radioactivity. Using azidobenzoyl-125I-ANF as a photoaffinity ligand, an ANF receptor with an apparent Mr of 138,000 was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The addition of unlabeled ANF (1 microM) to the incubation medium completely abolished the labeling of this protein band, but atriopeptin I (1 microM) or angiotensins I, II, and III (each 1 microM) were not effective in inhibiting the affinity labeling. The treatment of the neuroblastoma cells with ANF stimulated intracellular cyclic GMP levels in a dose-dependent manner with an EC50 of 5 nM. ANF (1 X 10(-7) M) stimulated cyclic GMP accumulation in less than 5 min by 30-fold as compared to the controls.
mesh_terms: D000345:Affinity Labels; D002460:Cell Line; D006152:Cyclic GMP / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D008970:Molecular Weight; D010525:Peripheral Nerves / Q000378:metabolism*; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*
chemical_list: D000345:Affinity Labels; D011956:Receptors, Cell Surface; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP