title: Bifunctional atrial natriuretic peptide receptor (type A) exists as a disulfide-linked tetramer in plasma membranes of bovine adrenal cortex.
abstract: Type A atrial natriuretic peptide (ANP) receptor was demonstrated to be present as a tetramer in the bovine adrenal cortex. Type A ANP receptor is composed of two functional domains, namely extracellular ANP-binding and cytoplasmic guanylate cyclase domains, and generally considered to be present as a single polypeptide chain of about 140 kDa based on its primary structure deduced from the cDNA sequence and its SDS/PAGE profile under reducing conditions. Characterization of the type A receptor or receptor/cyclase under non-reducing conditions led to the discovery stated in the title. The type A ANP receptor was partially purified from bovine adrenal cortex membranes by Blue-Sepharose and GTP-agarose chromatography. SDS-PAGE analysis of the receptor preparation revealed that although under reducing conditions it migrated as a 140-kDa band, the mobility of the receptor was greatly retarded in the absence of reducing agents, suggesting that the type A ANP receptor is present as a disulfide-linked oligomer in its native state. Further analysis using SDS-polyacrylamide-agarose gels suitable for determining the sizes of high-molecular-weight proteins revealed that the oligomer has an Mr of 500,000-550,000. This result clearly indicates that the native form of the type A receptor is a tetramer composed of four 140-kDa disulfide-linked receptor/cyclase molecules.
authors.affiliation: Department of Biological Sciences, Tokyo Institute of Technology.
authors.forename: T
authors.initials: T
authors.lastname: Iwata
authors.forename: K
authors.initials: K
authors.lastname: Uchida-Mizuno
authors.forename: T
authors.initials: T
authors.lastname: Katafuchi
authors.forename: T
authors.initials: T
authors.lastname: Ito
authors.forename: H
authors.initials: H
authors.lastname: Hagiwara
authors.forename: S
authors.initials: S
authors.lastname: Hirose
mesh_terms: D000302:Adrenal Cortex / Q000378:metabolism*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry; D008970:Molecular Weight; D011487:Protein Conformation; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000145:classification / Q000378:metabolism
chemical_list: D004220:Disulfides; D011956:Receptors, Cell Surface; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor