Molecular cloning and functional co-expression of a Caenorhabditis elegans nicotinic acetylcholine receptor subunit (acr-2)

Recept Channels. 1995;3(2):107-15.


A number of putative nicotinic acetylcholine receptor subunit clones were isolated by screening a lambda library of Caenorhabditis elegans genomic DNA with a probe derived from the Drosophila melanogaster ard gene (a non-alpha nicotinic acetylcholine receptor subunit clone). Studies on one of these loci, acr-2, are described; acr-2 is located between sup-7 and unc-6 on the X chromosome. A full-length cDNA was isolated and sequenced. The cDNA encodes a putative non-alpha subunit of a nicotinic acetylcholine receptor that shows many of the conserved features of vertebrate and invertebrate non-alpha nicotinic acetylcholine receptor subunits. To investigate the functional expression of the subunit, the corresponding cRNA was produced, in vitro, and micro-injected into Xenopus oocytes. When expressed alone acr-2 shows no levamisole-gated channel activity. When co-expressed with a C. elegans alpha subunit (unc-38), which is itself unable to form functional homo-oligomers, acr-2 contributed to the formation of a functional channel. This is the first functional expression of a nematode nicotinic acetylcholine receptor and supports the interpretation that the differentiation between alpha and non-alpha subunits dates back to the earliest stages of the evolution of the metazoa.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins*
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA, Complementary
  • Glycosylation
  • Helminth Proteins / genetics*
  • Helminth Proteins / metabolism
  • Ion Channel Gating
  • Ion Channels / genetics
  • Ion Channels / metabolism
  • Molecular Sequence Data
  • Phosphorylation
  • Receptors, Nicotinic / genetics*
  • Receptors, Nicotinic / metabolism
  • Sequence Homology, Amino Acid
  • Xenopus / genetics


  • Acr-2 protein, C elegans
  • Caenorhabditis elegans Proteins
  • DNA, Complementary
  • Helminth Proteins
  • Ion Channels
  • Receptors, Nicotinic

Associated data

  • GENBANK/X86403