Characterization of the hormone binding site of natriuretic peptide receptor-C.
The hormone binding site of rat and human natriuretic peptide clearance receptor (NPR-C), a single transmembrane receptor, has been further refined by mutagenesis. In addition to residue 188 (rat Ala, human Ile), which completely inverts the pharmacology of the rat and human receptors [Engel et al. (1994) J. Biol. Chem. 269, 17005-17008], we report a second key residue at position 205 (rat Tyr, human Asn) which modulates affinity to a limited number of ligands. Orthologous mutation of both residues results in tighter binding for human and weaker binding for rat NPR-C. The ligand binding fold of the receptor is formed by at least the first half of the extracellular domain containing two intramolecular disulfide loops, with the two affinity-modulating residues 188 and 205 in the second loop.
Engel
A M
AM
Cardiovascular Research Dept. Genentech, Inc. South San Francisco, CA 94080.
Lowe
D G
DG
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D001665:Binding Sites; D006162:Guanylate Cyclase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D016297:Mutagenesis, Site-Directed; D020097:Natriuretic Peptide, Brain; D020098:Natriuretic Peptide, C-Type; D009419:Nerve Tissue Proteins / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017461:Receptors, Atrial Natriuretic Factor / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship
D009419:Nerve Tissue Proteins; D011506:Proteins; D020097:Natriuretic Peptide, Brain; D020098:Natriuretic Peptide, C-Type; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; C073616:atrial natriuretic factor receptor C