Differential effects of cholera toxin on guanine nucleotide regulation of beta-adrenergic agonist high affinity binding and adenylate cyclase activation in frog erythrocyte membranes.

Published

Journal Article

The guanine nucleotide regulatory protein(s) regulates both adenylate cyclase activity and the affinity of adenylate cyclase-coupled receptors for hormones or agonist drugs. Cholera toxin catalyzes the covalent modification of the nucleotide regulatory protein of adenylate cyclase systems. Incubation of frog erythrocyte membranes with cholera toxin and NAD+ did not substantially alter the dose dependency for guanine nucleotide activation of adenylate cyclase activity. In contrast, toxin treated membranes demonstrated a 10 fold increase in the concentrations of guanine nucleotide required for a half maximal effect in regulating beta-adrenergic receptor affinity for the agonist (+/-) [3H]hydroxybenzylisoproterenol. The data emphasize the bifunctional nature of the guanine nucleotide regulatory protein and suggest that distinct structural domains of the guanine nucleotide regulatory protein may mediate the distinct regulatory effects on adenylate cyclase and receptor affinity for agonists.

Full Text

Duke Authors

Cited Authors

  • Stadel, JM; Lefkowitz, RJ

Published Date

  • 1981

Published In

Volume / Issue

  • 7 / 6

Start / End Page

  • 363 - 374

PubMed ID

  • 6125532

Pubmed Central ID

  • 6125532

International Standard Serial Number (ISSN)

  • 0095-1544

Language

  • eng

Conference Location

  • United States