title: STR-33, a novel G protein-coupled receptor that regulates locomotion and egg laying in Caenorhabditis elegans.
abstract: Despite their predicted functional importance, most G protein-coupled receptors (GPCRs) in Caenorhabditis elegans have remained largely uncharacterized. Here, we focused on one GPCR, STR-33, encoded by the str-33 gene, which was discovered through a ligand-based screening procedure. To characterize STR-33 function, we performed UV-trimethylpsolaren mutagenesis and isolated an str-33-null mutant. The resulting mutant showed hypersinusoidal movement and a hyperactive egg-laying phenotype. Two types of egg laying-related mutations have been characterized: egg laying-deficient (Egl-d) and hyperactive egg laying (Egl-c). The defect responsible for the egg laying-deficient Egl-d phenotype is related to Gα(q) signaling, whereas that responsible for the opposite, hyperactive egg-laying Egl-c phenotype is related to Gα(o) signaling. We found that the hyperactive egg-laying defect of the str-33(ykp001) mutant is dependent on the G protein GOA-1/Gα(o). Endogenous acetylcholine suppressed egg laying in C. elegans via a Gα(o)-signaling pathway by inhibiting serotonin biosynthesis or release from the hermaphrodite-specific neuron. Consistent with this, in vivo expression of the serotonin biosynthetic enzyme, TPH-1, was up-regulated in the str-33(ykp001) mutant. Taken together, these results suggest that the GPCR, STR-33, may be one of the neurotransmitter receptors that regulates locomotion and egg laying in C. elegans.
authors.affiliation: Department of Biochemistry and Yonsei Proteome Research Center, Yonsei University, Seoul 120-749, Korea.
authors.forename: Jeong-Eui
authors.initials: JE
authors.lastname: Lee
authors.forename: Pan-Young
authors.initials: PY
authors.lastname: Jeong
authors.forename: Hyoe-Jin
authors.initials: HJ
authors.lastname: Joo
authors.forename: Heekyeong
authors.initials: H
authors.lastname: Kim
authors.forename: Taehoon
authors.initials: T
authors.lastname: Lee
authors.forename: Hyeon-Sook
authors.initials: HS
authors.lastname: Koo
authors.forename: Young-Ki
authors.initials: YK
authors.lastname: Paik
mesh_terms: D000109:Acetylcholine / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000235:genetics / Q000378:metabolism*; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000235:genetics / Q000378:metabolism*; D008124:Locomotion / Q000502:physiology*; D016296:Mutagenesis; D009154:Mutation; D009474:Neurons / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D017981:Receptors, Neurotransmitter / Q000235:genetics / Q000378:metabolism*; D012098:Reproduction / Q000502:physiology; D012701:Serotonin / Q000096:biosynthesis / Q000235:genetics
chemical_list: D029742:Caenorhabditis elegans Proteins; C516620:GOA-1 protein, C elegans; D043562:Receptors, G-Protein-Coupled; D017981:Receptors, Neurotransmitter; C568999:STR-33 protein, C elegans; D012701:Serotonin; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D000109:Acetylcholine