Cloning of the cDNA for the human beta 1-adrenergic receptor.

Publisher Website
Google Scholar
Abstract
Screening of a human placenta .lambda.gt11 library has led to the isolation of the cDNA for the human .beta.1-adrenergic receptor (.beta.1AR). Used as the probe was the human genomic clone termed G-21. This clone, which contains an intronless gene for a putative receptor, was previously isolated by virtue of its cross hybridization with the human .beta.2-adrenergic receptor (.beta.2AR). The 2.4-kilobase cDNA for the human .beta.1AR encodes a protein of 477 amino acid residues that is 69% homologous with the avian .beta.AR but only 54% homologous with the human .beta.2AR. This suggests that the avian gene encoding .beta.AR and the human gene encoding .beta.1AR evolved from a common ancestral gene. RNA blot analysis indicates a message of 2.5 kilobases in rat tissues, with a pattern of tissue distribution consistent with .beta.1AR binding. This pattern is quite distinct from the pattern obtained when the .beta.2AR cDNA is used as a probe. Expression of receptor protein in Xenopus laevis oocytes conveys adenylate cyclase responsiveness to catecholamines with a typical .beta.1AR specificity. This contrasts with the typical .beta.2 subtype specificity observed when the human .beta.2AR cDNA is expressed in this system. Mammalian .beta.1AR and .beta.2AR are thus products of distinct genes, both of which are apparently related to the putative G-21 receptor.