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Preincubation of turkey erythrocytes with beta-adrenergic agonists leads to an attenuation of the responsiveness of adenylate cyclase to subsequent hormonal stimulation. Recently, our laboratory has shown (Stadel, J. M., Nambi, P., Shorr, R. G. L., Sawyer, D. D., Caron, M. G., and Lefkowitz, R. J. (1983) Proc. Natl. Acad. Sci. U. S. A. 80, 3173-3177) using 32Pi incorporation that phosphorylation of the beta-adrenergic receptor accompanies this desensitization process. We now report that, as determined from intracellular [gamma-32P] ATP specific activity measurements, this phosphorylation reaction occurs in a stoichiometric fashion. Under basal conditions there exists 0.75 +/- 0.1 mol of phosphate per mol of receptor whereas under maximally desensitized conditions this ratio increases to 2.34 +/- 0.13 mol/mol. This phosphorylation of the receptor is dose-dependent with respect to isoproterenol and exhibits a dose-response curve coincidental with that for isoproterenol-induced desensitization of adenylate cyclase. The time courses for receptor phosphorylation and adenylate cyclase desensitization are identical. In addition, the rate of resensitization of adenylate cyclase activity is comparable to the rate of return of the phosphate/receptor stoichiometries to control levels. Both the phosphorylation and desensitization reactions are pharmacologically specific as indicated by the high degree of stereoselectivity, rank order of catecholamines, and blockade by the specific beta-adrenergic antagonist, propranolol. Incubation of turkey erythrocytes with cAMP and cAMP analogs maximally activates cAMP-dependent protein kinase but only partially mimics isoproterenol in promoting phosphorylation of the receptor in concordance with their partial effects in inducing desensitization. Conversely, activators or inhibitors of Ca2+/calmodulin kinase or protein kinase C do not affect the isoproterenol-induced desensitization. These results indicate that desensitization of turkey erythrocyte adenylate cyclase is highly correlated with phosphorylation of the beta-adrenergic receptor and that these events are mediated, at least partially, by cAMP.
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
June 1983,
Proceedings of the National Academy of Sciences of the United States of America,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
January 1983,
Transactions of the Association of American Physicians,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
April 1985,
The Journal of biological chemistry,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
July 1984,
Proceedings of the National Academy of Sciences of the United States of America,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
October 1979,
Journal of cyclic nucleotide research,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
July 1980,
The Journal of biological chemistry,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
August 1982,
The Journal of biological chemistry,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
September 1977,
Proceedings of the National Academy of Sciences of the United States of America,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
August 1973,
The Journal of biological chemistry,
D R Sibley, and
J R Peters, and
P Nambi, and
M G Caron, and
R J Lefkowitz
March 1983,
Pharmacological reviews,
