Nonredundant function of two highly homologous octopamine receptors in food-deprivation-mediated signaling in Caenorhabditis elegans.
It is common for neurotransmitters to possess multiple receptors that couple to the same intracellular signaling molecules. This study analyzes two highly homologous G-protein-coupled octopamine receptors using the model animal Caenorhabditis elegans. In C. elegans, the amine neurotransmitter octopamine induces activation of cAMP response element-binding protein (CREB) in the cholinergic SIA neurons in the absence of food through activation of the Gq-coupled octopamine receptor SER-3 in these neurons. We also analyzed another Gq-coupled octopamine receptor, SER-6, that is highly homologous to SER-3. As seen in ser-3 deletion mutants, octopamine- and food-deprivation-mediated CREB activation was decreased in ser-6 deletion mutants compared with wild-type animals, suggesting that both SER-3 and SER-6 are required for signal transduction. Cell-specific expression of SER-6 in the SIA neurons was sufficient to restore CREB activation in the ser-6 mutants, indicating that SER-6, like SER-3, functions in these neurons. Taken together, these results demonstrate that two similar G-protein-coupled receptors, SER-3 and SER-6, function in the same cells in a nonredundant manner.
Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan.
Midori
M
Yoshida
Eitaro
E
Oami
Min
M
Wang
Shoichi
S
Ishiura
Satoshi
S
Suo
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D030801:Animals, Genetically Modified; D050882:CREB-Binding Protein / Q000378:metabolism; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D005508:Food Deprivation / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D009474:Neurons / Q000378:metabolism*; D009655:Octopamine / Q000494:pharmacology; D010802:Phylogeny; D017982:Receptors, Biogenic Amine / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000235:genetics / Q000378:metabolism*; D044406:Receptors, Serotonin, 5-HT3 / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome / Q000187:drug effects / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D029742:Caenorhabditis elegans Proteins; D017982:Receptors, Biogenic Amine; D011985:Receptors, Serotonin; D044406:Receptors, Serotonin, 5-HT3; C027604:norsynephrine receptor; C097216:serotonin 6 receptor; D009655:Octopamine; D050882:CREB-Binding Protein
C. elegans; CREB; G-protein-coupled receptor; food deprivation; octopamine