Characterization of a novel D2-like dopamine receptor with a truncated splice variant and a D1-like dopamine receptor unique to invertebrates from Caenorhabditis elegans

J Neurochem. 2005 Aug;94(4):1146-57. doi: 10.1111/j.1471-4159.2005.03268.x. Epub 2005 Jul 7.


We have cloned two novel Caenorhabditis elegans dopamine receptors, DOP-3 and DOP-4. DOP-3 shows high sequence homology with other D2-like dopamine receptors. As a result of alternative splicing, a truncated splice variant of DOP-3, DOP-3nf, was produced. Because of the in-frame insertion of a stop codon in the third intracellular loop, DOP-3nf lacks the sixth and seventh transmembrane domains that are found in the full-length DOP-3 receptor. Reporter gene assay showed that DOP-3 attenuates forskolin-stimulated cAMP formation in response to dopamine stimulation, whereas DOP-3nf does not. When DOP-3 was coexpressed with DOP-3nf, the ability to inhibit forskolin-stimulated cAMP formation was reduced. DOP-4 shows high sequence homology with D1-like dopamine receptors unique to invertebrates, which are distinct from mammalian D1-like dopamine receptors. Reporter gene assay showed that DOP-4 stimulates cAMP accumulation in response to dopamine stimulation. These two receptors provide new opportunities to understand dopaminergic signaling at the molecular level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • CHO Cells
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Caenorhabditis elegans Proteins / physiology*
  • Cell Line
  • Cloning, Molecular
  • Cricetinae
  • Cricetulus
  • DNA, Recombinant*
  • Female
  • Genetic Variation*
  • Humans
  • Ligands
  • Male
  • Molecular Sequence Data
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Peptide Fragments / physiology
  • Receptors, Dopamine D2 / genetics
  • Receptors, Dopamine D2 / metabolism
  • Receptors, Dopamine D2 / physiology*
  • Tissue Distribution


  • Caenorhabditis elegans Proteins
  • DNA, Recombinant
  • DOP-3 protein, C elegans
  • DOP-4 protein, C elegans
  • Ligands
  • Peptide Fragments
  • Receptors, Dopamine D2