Interaction of beta-adrenergic receptors with the inhibitory guanine nucleotide-binding protein of adenylate cyclase in membranes prepared from cyc- S49 lymphoma cells.
beta-Adrenergic receptors on membranes prepared from L6 myoblasts, wild-type S49 lymphoma cells, and an adenylate cyclase-deficient variant (cyc-) of S49 lymphoma cells bind the agonist [3H]hydroxybenzylisoproterenol ([3H]HBI) with high affinity. In each case the agonist [3H]HBI is associated with a larger complex than is the antagonist [125I]iodopindolol, and the binding of [3H]HBI can be inhibited by GTP. These observations suggest that there is an agonist-dependent association of the receptor with a guanine nucleotide-binding protein. The goal of the present experiments was to investigate the possibility that an interaction of beta-adrenergic receptors with the inhibitory guanine nucleotide-binding protein of adenylate cyclase was responsible for these observations. Treatment of S49 cells with pertussis toxin decreased the extent of pertussis toxin-catalyzed [32P]ADP-ribosylation of a 41,000-dalton protein, measured in vitro, and decreased the inhibition of adenylate cyclase activity observed in the presence of somatostatin or analogues of GTP. Isoproterenol-stimulated adenylate cyclase activity was potentiated following treatment of wild-type S49 cells and L6 myoblasts with pertussis toxin. Although the ability of receptors on membranes prepared from L6 myoblasts to bind the agonist [3H]HBI was not affected by treatment of cells with pertussis toxin, treatment of cyc- S49 cells with pertussis toxin markedly decreased the ability of receptors to bind [3H]HBI. The observed inhibition of the binding of the agonist [3H]HBI to beta-adrenergic receptors on membranes prepared from cyc- S49 cells after treatment with pertussis toxin could be explained by an interaction between beta-adrenergic receptors and the inhibitory guanine nucleotide-binding protein. Such an interaction may represent a mechanism through which stimulation of the activity of adenylate cyclase by beta-adrenergic receptors can be regulated or through which beta-adrenergic receptors can affect the activity of cyclic AMP-independent cellular processes.
Abramson
S N
SN
Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia 19104-6084.
Martin
M W
MW
Hughes
A R
AR
Harden
T K
TK
Neve
K A
KA
Barrett
D A
DA
Molinoff
P B
PB
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007545:Isoproterenol / Q000031:analogs & derivatives / Q000378:metabolism; D008223:Lymphoma / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D037342:Pertussis Toxin; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D037361:Adenylate Cyclase Toxin; D011943:Receptors, Adrenergic, beta; D010566:Virulence Factors, Bordetella; D009243:NAD; D000246:Adenosine Diphosphate Ribose; C015272:hydroxybenzylisoproterenol; C029247:3-iodopindolol; D010869:Pindolol; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D007545:Isoproterenol