Phosphorylation of the predicted major intracellular domains of the rat and chick neuronal nicotinic acetylcholine receptor alpha 7 subunit by cAMP-dependent protein kinase

Neuropharmacology. 1996;35(8):1023-8. doi: 10.1016/s0028-3908(96)00083-4.


The predicted major intracellular domains of the chick and rat neuronal nicotinic acetylcholine receptor alpha 7 subunits were expressed in E. coli as glutathione-S-transferase fusion proteins. These proteins were then purified to near homogeneity by chromatography on immobilized glutathione. The intracellular domains of the alpha 7 subunit from both species were phosphorylated to high stoichiometry by cAMP-dependent protein kinase, but not by protein kinase C, cGMP-dependent protein kinase, or calcium/calmodulin-dependent protein kinase. Phosphorylation occurred on serine residues only within an identical single tryptic peptide for both proteins. This conserved phosphorylation site was identified as Ser 342 utilizing site-directed mutagenesis. These results demonstrate that the intracellular domain of the alpha 7 subunit is a substrate of PKA, and suggest a role for protein phosphorylation in mediating cellular regulation upon neuronal AChRs containing this subunit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chick Embryo
  • Conserved Sequence
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Glutathione Transferase / genetics
  • Glutathione Transferase / isolation & purification
  • Molecular Sequence Data
  • Neurons / metabolism*
  • Peptide Mapping
  • Phosphorylation
  • Plasmids
  • Rats
  • Receptors, Nicotinic / metabolism*
  • Recombinant Fusion Proteins / biosynthesis


  • Receptors, Nicotinic
  • Recombinant Fusion Proteins
  • Glutathione Transferase
  • Cyclic AMP-Dependent Protein Kinases