title: Identification and molecular characterization of the G alpha12-Rho guanine nucleotide exchange factor pathway in Caenorhabditis elegans.
abstract: G alpha 12/13-mediated pathways have been shown to be involved in various fundamental cellular functions in mammalian cells such as axonal guidance, apoptosis, and chemotaxis. Here, we identified a homologue of Rho-guanine nucleotide exchange factor (GEF) in Caenorhabditis elegans (CeRhoGEF), which functions downstream of gpa-12, the C. elegans homologue of G alpha 12/13. CeRhoGEF contains a PSD-95/Dlg/ZO-1 domain and a regulator of G protein signaling (RGS) domain upstream of the Dbl homology-pleckstrin homology region similar to mammalian RhoGEFs with RGS domains, PSD-95/Dlg/ZO-1-RhoGEF and leukemia-associated RhoGEF. It has been shown in mammalian cells that these RhoGEFs interact with activated forms of G alpha 12 or G alpha 13 through their RGS domains. We demonstrated by coimmunoprecipitation that the RGS domain of CeRhoGEF interacts with GPA-12 in an AIF4- activation-dependent manner and confirmed that the Dbl homology-pleckstrin homology domain of CeRhoGEF was capable of Rho-dependent signaling. These results proved conservation of the G alpha 12-RhoGEF pathway in C. elegans. Expression of DsRed or GFP under the control of the promoter of CeRhoGEF or gpa-12 revealed an overlap of their expression patterns in ventral cord motor neurons and several neurons in the head. RNA-mediated gene interference for CeRhoGEF and gpa-12 resulted in similar phenotypes such as embryonic lethality and sensory and locomotive defects in adults. Thus, the G alpha 12/13-RhoGEF pathway is likely to be involved in embryonic development and neuronal function in C. elegans.
authors.affiliation: Department of Pharmacology, University of Illinois, Chicago, IL 60612, USA.
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Yau
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Yokoyama
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Goshima
authors.forename: Zeba K
authors.initials: ZK
authors.lastname: Siddiqui
authors.forename: Shahid S
authors.initials: SS
authors.lastname: Siddiqui
authors.forename: Tohru
authors.initials: T
authors.lastname: Kozasa
mesh_terms: D000486:Allergy and Immunology; D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D019556:COS Cells; D017173:Caenorhabditis elegans; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004330:Drosophila; D044365:GTP-Binding Protein alpha Subunits, G12-G13 / Q000737:chemistry* / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism; D049452:Green Fluorescent Proteins; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry; D008156:Luciferases / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D020710:RGS Proteins; D034622:RNA Interference; D015398:Signal Transduction
chemical_list: D018076:DNA, Complementary; D020662:Guanine Nucleotide Exchange Factors; D008164:Luminescent Proteins; D020710:RGS Proteins; C413663:fluorescent protein 583; D049452:Green Fluorescent Proteins; D008156:Luciferases; D019204:GTP-Binding Proteins; D044365:GTP-Binding Protein alpha Subunits, G12-G13