Beta-agonist-induced inhibitory-guanine-nucleotide-binding regulatory protein coupling to adenylate cyclase in mollusc Anodonta cygnea foot muscle sarcolemma.
In the sarcolemma fraction of foot muscles of a fresh-water bivalve mollusc, Anodonta cygnea, a direct inhibitory, rather than stimulatory, effect of the beta-adrenergic agonist isoproterenol, at micromolar concentration, on cAMP level and adenylate cyclase activity, was revealed. It was blocked by beta- but not alpha-adrenergic antagonists. A single class of [3H]dihydroalprenolol-binding sites with binding properties of beta-adrenergic receptor was detected in mollusc sarcolemma. Potentiation of the inhibitory effect of isoproterenol on mollusc adenylate cyclase activity by GTP or guanosine 5'-[beta,gamma-imido]triphosphate at micromolar concentrations, and its elimination in the presence of guanosine 5'-[beta-thio]diphosphate, were shown. The pertussis-toxin-induced ADP-ribosylation of sarcolemma 40-kDa protein [immunochemically related in the C-terminal part to pertussis-toxin-sensitive guanine-nucleotide-binding regulatory protein (G-protein) alpha subunits of vertebrates], as well as the treatment of mollusc sarcolemma with antisera responsive to the C-terminus of vertebrate inhibitory G-protein (G(i)) alpha subunit led to elimination of the inhibitory effect of isoproterenol on adenylate cyclase activity. The results obtained suggest that beta-agonist-induced inhibition of adenylate cyclase in A. cygnea foot muscle may be realized via the beta-adrenoreceptor/G(i) signalling pathway.
Pertseva
M N
MN
Laboratory of Evolution of Biochemical Communication Systems, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg.
Kuznetzova
L A
LA
Plesneva
S A
SA
Grishin
A V
AV
Panchenko
M P
MP
D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D000242:Cyclic AMP / Q000378:metabolism; D004082:Dihydroalprenolol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology; D008969:Molecular Sequence Data; D008974:Mollusca / Q000201:enzymology*; D009132:Muscles / Q000201:enzymology*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects* / Q000378:metabolism; D012508:Sarcolemma / Q000201:enzymology
D000067956:Adenylyl Cyclase Inhibitors; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D000242:Cyclic AMP; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D007545:Isoproterenol