Cloning of the gene and cDNA for mammalian β-adrenergic receptor and homology with rhodopsin

Abstract

The adenylate cyclase system, which consists of a catalytic moiety and regulatory guanine nucleotide-binding proteins, provides the effector mechanism for the intracellular actions of many hormones and drugs. The tissue specificity of the system is determined by the particular receptors that a cell expresses. Of the many receptors known to modulate adenylate cyclase activity, the best characterized and one of the most pharmacologically important is the beta-adrenergic receptor (beta AR). The pharmacologically distinguishable subtypes of the beta-adrenergic receptor, beta 1 and beta 2 receptors, stimulate adenylate cyclase on binding specific catecholamines. Recently, the avian erythrocyte beta 1, the amphibian erythrocyte beta 2 and the mammalian lung beta 2 receptors have been purified to homogeneity and demonstrated to retain binding activity in detergent-solubilized form. Moreover, the beta-adrenergic receptor has been reconstituted with the other components of the adenylate cyclase system in vitro, thus making this hormone receptor particularly attractive for studies of the mechanism of receptor action. This situation is in contrast to that for the receptors for growth factors and insulin, where the primary biochemical effectors of receptor action are unknown. Here, we report the cloning of the gene and cDNA for the mammalian beta 2AR. Analysis of the amino-acid sequence predicted for the beta AR indicates significant amino-acid homology with bovine rhodopsin and suggests that, like rhodopsin, beta AR possesses multiple membrane-spanning regions.

The distribution of a dopamine D2 receptor mRNA in rat brain

“…The widespread distribution of this mRNA has important implications with regard to the pharmacology of dopamine receptors and future prospects for the development of dopaminergic drugs which discriminate between receptors located in these different brain regions. In the case of other G-protein coupled receptors, it has been shown that when the same receptor genes are expressed in different cells, their antagonist pharmacology does not vary with respect to cell type [25,26,36], while agonist pharmacology varies with respect to both cell type and levels of receptor ( [28] and unpublished observations). Initial results with the cloned D2 receptors indicate that a similar relationship may hold since D2 receptors expressed in fibroblasts have the same affinity for antagonists and a lower affinity for agonists than do D2 receptors expressed by brain [30].…”

“…For example, several subtypes of muscarinic, serotonergic, and adrenergic receptors have now been cloned [19][20][21][22][23][24][25][26]. These receptor subtypes are expressed in distinct regions of the brain, and in the case of muscarinic receptors, different receptor gene products are expressed in presynaptic versus postsynaptic locations [27][28][29].…”

Trace amine-associated receptor 1—Family archetype or iconoclast?

“…Among the explanations suggested to explain this outcome are their relatively small size, limited abundance, and hydrophobic nature. Hard won, some receptor protein sequence information eventually began to emerge that led to the successful cloning of cDNAs and genes for the opsins (Nathans & Hogness, 1983;Nathans & Hogness, 1984;Nathans et al, 1986) and the hamster beta2-adrenergic receptor (Dixon et al, 1986;Kobilka et al, 1987). Even with the limited number of examples available at the time molecular neurobiologists following these developments latched on immediately to the remarkable extent of amino acid sequence and structural conservation, in particular the presence of 7 putative transmembrane (TM) domains, shared by these integral membrane proteins.…”

Phorbol‐ester‐induced phosphorylation of the β2‐adrenergic receptor decreases its coupling to Gs

“…myristate 13c~-acetate: PKC, protein kinase C; G. stimulatory guanine.nucleottde-blndlng proteifJ~ G~, inhibitory guanine-nucleo. tide-binding protein; Pl0 phospho-lnositides; [12~I]CYP, [t2Sllcyano-pindolol; CHW, Chinese hamster fibroblast; DMEM, Dulbecco's minimum Eagle's medium In sharp contrast, phorbol-ester treatment has been shown to induce a desensitization of the ~-adrenergicstimulated adenylyl cyclase in avian erythrocytes [14,15], Desensitization was accompanied by an increased phosphorylation of the ~a-adrenergic receptor (#2AR), It was susgested that PKC-mediated phosphorylation of the receptor could contribute to this desensitization, The mammalian B2AR receptor has been shown to be an in vitro substrata for PKC [20], and potential PKC phosphorylation sites are apparent m its primary structure [21,22]. Thus, questions arise concerning the role of the PKC-mediated phosphoryla, tion of the ~2AR in mammalian cellular systems.…”