The m3 muscarinic acetylcholine receptor is coupled to mitogen-activated protein kinase via protein kinase C and epidermal growth factor receptor kinase

Biochem J. 2000 Jun 1;348 Pt 2(Pt 2):381-7.

Abstract

The acetylcholine analogue carbachol rapidly activated mitogen-activated protein kinase (MAPK), and caused tyrosine phosphorylation of the adapter protein p52 Shc and the epidermalgrowth factor (EGF) receptor, in human embryonic kidney cells stably expressing m3 muscarinic receptors. The protein kinase C (PKC) inhibitor GF109203X caused a significant partial inhibition of m3 receptor-mediated activation of MAPK. The PKC-independent MAPK activity elicited by carbachol in the presence of GF109203X was reproducibly abolished by AG1478, an inhibitor of EGF-receptor tyrosine kinase activity, and by the Src tyrosine kinase inhibitor PP1. In a subset of these experiments, GF109203X concomitantly increased carbachol-induced tyrosine phosphorylation of p52 Shc and the EGF receptor. In co-stimulation experiments, carbachol and EGF activated MAPK in a non-additive fashion; moreover, EGF-induced association of Shc with the phosphorylated EGF receptor was inhibited by carbachol. This effect of carbachol was blocked by GF109203X. The results indicate that MAPK activation by m3 receptor stimulation is regulated by two pathways; one dependent on PKC, and the other mediated via the EGF receptor and Src. Moreover, the EGF-receptor-dependent pathway may be subject to negative-feedback regulation via m3 receptor-coupled activation of PKC.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Carbachol / pharmacology
  • Cell Line
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors / drug effects
  • ErbB Receptors / metabolism*
  • Humans
  • Indoles / pharmacology
  • Maleimides / pharmacology
  • Mitogen-Activated Protein Kinases / metabolism*
  • Protein Kinase C / metabolism*
  • Receptor, Muscarinic M3
  • Receptors, Muscarinic / drug effects
  • Receptors, Muscarinic / physiology*
  • Recombinant Proteins / metabolism
  • Tetradecanoylphorbol Acetate / pharmacology
  • Transfection

Substances

  • Enzyme Inhibitors
  • Indoles
  • Maleimides
  • Receptor, Muscarinic M3
  • Receptors, Muscarinic
  • Recombinant Proteins
  • Epidermal Growth Factor
  • Carbachol
  • ErbB Receptors
  • Protein Kinase C
  • Mitogen-Activated Protein Kinases
  • bisindolylmaleimide I
  • Tetradecanoylphorbol Acetate