Cloning and expression of a G protein-linked acetylcholine receptor from Caenorhabditis elegans

J Neurochem. 1999 Jan;72(1):58-65. doi: 10.1046/j.1471-4159.1999.0720058.x.

Abstract

We have isolated a cDNA clone from the nematode Caenorhabditis elegans that encodes a protein of greatest sequence similarity to muscarinic acetylcholine receptors. This gene codes for a polypeptide of 682 amino acids containing seven putative transmembrane domains. The amino acid identities, excluding a highly variable middle portion of the third intracellular loop, to the human m1-m5 receptors are 28-34%. When this cloned receptor was coexpressed with a G protein-gated inwardly rectifying K+ channel (GIRK1) in Xenopus oocyte, acetylcholine was able to elicit the GIRK current. This acetylcholine-induced current was substantially inhibited by the muscarinic antagonist atropine in a reversible manner. However, another muscarinic agonist oxotremorine and antagonists scopolamine and pirenzepine had little or negligible effects on this receptor. Taken together, these results suggest that the cloned gene encodes a G protein-linked acetylcholine receptor that is most similar to but pharmacologically distinct from muscarinic acetylcholine receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / pharmacology
  • Animals
  • Atropine / pharmacology
  • Base Sequence
  • Blotting, Southern
  • Caenorhabditis elegans / genetics*
  • Cloning, Molecular
  • DNA, Complementary
  • Electrophysiology
  • Free Radical Scavengers / pharmacology
  • G Protein-Coupled Inwardly-Rectifying Potassium Channels
  • GTP-Binding Proteins / metabolism*
  • Ion Channel Gating / drug effects
  • Ion Channel Gating / physiology*
  • Isoproterenol / pharmacology
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Molecular Sequence Data
  • Muscarinic Agonists / pharmacology
  • Muscarinic Antagonists / pharmacology
  • Oocytes / physiology
  • Oxotremorine / pharmacology
  • Pirenzepine / pharmacology
  • Potassium Channels / physiology
  • Potassium Channels, Inwardly Rectifying*
  • Receptors, Muscarinic / genetics*
  • Receptors, Muscarinic / metabolism*
  • Scopolamine / pharmacology
  • Sequence Homology, Amino Acid
  • Serotonin / pharmacology
  • Sympathomimetics / pharmacology
  • Vasodilator Agents / pharmacology
  • Xenopus

Substances

  • DNA, Complementary
  • Free Radical Scavengers
  • G Protein-Coupled Inwardly-Rectifying Potassium Channels
  • Muscarinic Agonists
  • Muscarinic Antagonists
  • Potassium Channels
  • Potassium Channels, Inwardly Rectifying
  • Receptors, Muscarinic
  • Sympathomimetics
  • Vasodilator Agents
  • Serotonin
  • Pirenzepine
  • Oxotremorine
  • Atropine
  • Scopolamine
  • GTP-Binding Proteins
  • Isoproterenol
  • Acetylcholine

Associated data

  • GENBANK/AF075245