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.
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.
Sugiura
Mai
M
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Meguro-ku, Tokyo, Japan.
Fuke
Satoshi
S
Suo
Satoshi
S
Sasagawa
Noboru
N
Van Tol
Hubert H M
HH
Ishiura
Shoichi
S
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D017173:Caenorhabditis elegans / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D004274:DNA, Recombinant; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008024:Ligands; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D017448:Receptors, Dopamine D2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014018:Tissue Distribution
D029742:Caenorhabditis elegans Proteins; D004274:DNA, Recombinant; C494134:DOP-3 protein, C elegans; C503952:DOP-4 protein, C elegans; D008024:Ligands; D010446:Peptide Fragments; D017448:Receptors, Dopamine D2