C10 Regulation of ion channels by adenosine

✍ Scribed by Thomas Dunwiddie

• Publisher: Elsevier Science
• Year: 1992
• Tongue: French
• Weight: 161 KB
• Volume: 6
• Category: Article
• ISSN: 0985-0562
• DOI: 10.1016/s0985-0562(05)80385-1

✦ Synopsis

RESUM]~S DES COMMUNICATIONS : AD]~NOS1NE

thus, tissue specific differences in adenosine receptor subtypes that have been proposed on the bases of subtle pharmacological differences in ligand binding have not yet been identified. All of the adenosine receptors couple to GTP binding proteins and.share features common to this superfamily: seven stretches of 21-28 hydrophobic amino acids, representating putative transmembrane domains, linked by regions of greater hydrophilicity. There is great similarity in the amino acid sequences of the adenosine receptor family, particularly in transmembrane segments 2 and 3, suggesting that these, and possibly other transmembrane segments are involved in ligand recognition. Recombinant receptors have been expressed transiently in COS cells and Xenopus oocytee, and permanently in CHO or 31"3 cells. Recombinant receptors retain features and species differences noted in native receptors with regard to ligand binding affinities and stimulation (A~.) or inhibition (A~) of adenylyl cyclase. Currently attempts are underway to identify additional adenosine receptor subtypes, and to further characterize receptor by in situ hybridization and site-directed mutaganasis.