title: Expression of an oncogenic mutant G alpha i2 activates Ras in Rat-1 fibroblast cells.
abstract: It has been reported that expression of the active mutant of heterotrimeric GTP-binding protein alpha subunit G alpha i2 transforms Rat-1 cells. However, the G alpha i2-mediated mitogenic signaling pathways remain to be elucidated. Here, we demonstrate that inducible expression of the active mutant of G alpha i2 (G alpha i2(Q205L)) activates Ras and c-Jun N-terminal kinase (JNK) in addition to extracellular signal-regulated kinase (ERK) in Rat-1 cells. Our findings suggest that Ras may play a critical role in the G alpha i2-induced transformation and G alpha i2 can transduce signals from the Gi-coupled receptor to JNK and ERK in certain types of mammalian cells.
authors.affiliation: Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Edamatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Kaziro
authors.forename: H
authors.initials: H
authors.lastname: Itoh
mesh_terms: D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D004789:Enzyme Activation; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D005347:Fibroblasts; D005419:Flavonoids / Q000494:pharmacology; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D019204:GTP-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D020928:Mitogen-Activated Protein Kinases; D008934:Mitogens / Q000378:metabolism; D009154:Mutation; D010766:Phosphorylation; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014357:Trypsin / Q000378:metabolism; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D008934:Mitogens; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D004815:Epidermal Growth Factor; D006160:Guanosine Triphosphate; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D020928:Mitogen-Activated Protein Kinases; D014357:Trypsin; D019204:GTP-Binding Proteins; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; C498017:Gnai2 protein, rat; D018631:ras Proteins; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one