ACR-3, a Caenorhabditis elegans nicotinic acetylcholine receptor subunit. Molecular cloning and functional expression

Recept Channels. 1997;5(3-4):149-58.


The molecular cloning and functional co-expression of a novel nicotinic acetylcholine receptor (nAChR) non-alpha subunit gene, acr-3, is described. Previously we determined the sequence and demonstrated the functional co-expression of acr-2, a nAChR non-alpha subunit gene from Caenorhabditis elegans. Analysis of the acr-2 genomic DNA revealed the existence of another potential nAChR subunit gene, acr-3, in the same orientation, only 281 bp downstream of acr-2. A cDNA containing the entire acr-3 coding sequence was isolated by RT-PCR and sequenced. The predicted protein contains the conserved features typical of nAChR non-alpha subunits and most closely resembles other invertebrate nAChR non-alpha polypeptides. Unusually, the highly conserved glycine residue (equivalent to residue 240 in the Torpedo alpha subunit) upstream of transmembrane domain 2 (m2) is replaced by a serine residue in ACR-3. When acr-3 cDNA was injected alone into Xenopus oocytes no levamisole-gated channel activity was observed. However when co-expressed with a C. elegans alpha subunit (UNC-38), ACR-3 contributed to the formation of levamisole-gated channels. The response of this hetero-oligomer to levamisole (100 microM) was reduced by the nAChR antagonists mecamylamine (1 microM) and d-tubocurarine (10 microM).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins*
  • Cloning, Molecular
  • DNA, Complementary
  • DNA, Helminth
  • Gene Expression
  • Glycosylation
  • Helminth Proteins / classification
  • Helminth Proteins / genetics*
  • Helminth Proteins / metabolism
  • Molecular Sequence Data
  • Phosphorylation
  • Receptors, Nicotinic / classification
  • Receptors, Nicotinic / genetics*
  • Receptors, Nicotinic / metabolism
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Xenopus laevis


  • ACR-3 protein, C elegans
  • Caenorhabditis elegans Proteins
  • DNA, Complementary
  • DNA, Helminth
  • Helminth Proteins
  • Receptors, Nicotinic

Associated data

  • GENBANK/Y08637