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Identification of the receptor for atrial natriuretic factor on cultured vascular cells.

1985; Elsevier BV; Volume: 260; Issue: 28 Linguagem: Inglês

10.1016/s0021-9258(18)95674-7

1083-351X

Dale B. Schenk, M N Phelps, J G Porter, Robert M. Scarborough, Glenn McEnroe, John Lewicki,

RNA and protein synthesis mechanisms

Binding experiments with 12'I-atrial natriuretic factor (ANF) followed by covalent attachment with disuccimidyl suberate show that the peptide binds predominantly to a protein of apparent molecular mass of 66,000 daltons on the cell surface of cultured bovine aortic smooth muscle cells.A minor protein species of 180,000 M, is also visualized after cross-linking.Endothelial cells, however, whose ANF binding parameters differ substantially from smooth muscle cells, also appear to have qualitatively identical 1251-ANF binding proteins.The identity of these putative proteins, as the ANF receptor, is confirmed by findings that covalent attachment of 1251-ANF is saturable, concentrationdependent, and competed by nanomolar concentrations of unlabeled ANF.Furthermore, other peptide hormones such as angiotensin 11, glucagon, or insulin are ineffective in competing for lZ5I-ANF binding and cross-linking to the receptor.Atrial natriuretic factor (ANF1) has recently been shown to have potent biological effects on both renal (1-3) and vascular tissue (4, 5).These effects appear to be mediated through specific binding of ANF to receptors (6-9).Following ANF binding, a series of events occur that are thought to include, in part, increases in levels of intracellular cGMP (7,lO).The relationship between ANF binding and these events, however, has not been shown to be strictly causal.This conclusion is based upon the lack of structural evidence for a specific receptor.Furthermore, binding studies employing T -A N F are complicated by the findings that differences in the Kd values for peptide binding in different tissues exist, as well as possible discrepancies between Kd and EC50 values for ANF binding and elevation of cGMP within cells (6,8,10).Recently Yip et al. (11) identified a putative ANF receptor in plasma membranes of rat kidney cortex with a molecular weight of 140,000 daltons using a photoaffinity ANF analogue, [lZ5I] azidoiodosalicyl-ANF (ASA-ANF) (11).Unfortunately, micromolar concentrations of unlabeled ANF were required to compete for the cross-linking reaction, an apparent discrep-