Regulation of phosphorylation of nicotinic acetylcholine receptors in mouse BC3H1 myocytes.
- 1 September 1987
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 84 (18), 6601-6605
- https://doi.org/10.1073/pnas.84.18.6601
Abstract
By using 32P-labeling methods and performing immunoprecipitations with specific antibodies, we have found that three subunits of the nicotinic acetylcholine receptor are phosphorylated in mouse skeletal muscle cells. In nonstimulated cells, the molar ratios of phosphate estimated in .alpha., .beta., and .delta. subunits were 0.02, 0.05, and 0.5, respectively. All three subunits contained predominantly phosphoserine with some phosphothreonine; the .beta. subunit also contained phosphotyrosine. Incubating cells with agents that stimulate cAMP-dependent pathways (isoproterenol, forskolin, 8-Br-cAMP) increased the phosphorylation of the .delta. subunit by 50%, but phosphate labeling of the .beta. subunit was depressed by a third. In contrast, when cells were incubated with the divalent cation ionophores A-23187 or ionomycin, phosphorylation of both the .delta. and .beta. subunits increased. The results indicate that acetylcholine receptors are phosphorylated to significant levels in skeletal muscle cells and that cAMP-dependent and Ca2+-dependent pathways exist for controlling the phosphorylation state of the receptor subunits.Keywords
This publication has 31 references indexed in Scilit:
- The βγ subunits of GTP-binding proteins activate the muscarinic K+ channel in heartNature, 1987
- Phosphorylation of the nicotinic acetylcholine receptor regulates its rate of desensitizationNature, 1986
- Location of antigenic determinants of primary sequences of the subunits of nicotinic acetylcholine receptor by peptide mappingBiochemistry, 1986
- Phosphorylation of Ion channelsThe Journal of Membrane Biology, 1985
- Effects of monoclonal antibodies on the function of acetylcholine receptors purified from Torpedo californica and reconstituted into vesiclesBiochemistry, 1985
- [42] Detection and quantification of phosphotyrosine in proteinsMethods in Enzymology, 1983
- Studies of the composition of purified Torpedo californica acetylcholine receptor and of its subunitsBiochemistry, 1979
- In vitro phosphorylation of the acetylcholine receptorNature, 1977
- Phosphorylation of acetylcholine receptor by endogenous membrane protein kinase in receptor-enriched membranes of Torpedo californicaNature, 1977
- A rapid method for the measurement of [γ-32P]ATP specific radioactivity in tissue extracts and its application to the study of 32Pi uptake in perfused rat heartAnalytical Biochemistry, 1976