title: The dominant negative effects of H-Ras harboring a Gly to Ala mutation at position 60.
abstract: v-H-Ras harboring the Gly-60 to Ala mutation (G60A) lacks the ability to induce germinal vesicle breakdown in Xenopus oocytes. Moreover, this mutant is capable of inhibiting the activity of v-H-Ras to induce oocyte germinal vesicle breakdown when co-injected. The duration and the extent of inhibition depends on the molar ratio of v-H-Ras(G60A) to v-H-Ras. The inhibition is not due to a general toxicity of v-H-Ras(G60A) to oocytes because oocytes injected with v-H-Ras(G60A) can be readily induced to mature by other mitogenic agents, such as insulin, insulin-like growth factor 1, insulin-like growth factor 2, and phosphatidylcholine-specific phospholipase C. The dominant negative effect of v-H-Ras(G60A) requires proper membrane attachment of v-H-Ras(G60A). By using a competition assay, it was concluded that the dominant negative phenotype of v-H-Ras(G60A) resulted from sequestering H-Ras downstream effector(s). Raf-1 was identified as one of the sequestered targets.
authors.affiliation: Molecular Biology Department, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Sung
authors.forename: M C
authors.initials: MC
authors.lastname: Hwang
authors.forename: Y W
authors.initials: YW
authors.lastname: Hwang
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D020690:GTPase-Activating Proteins; D005799:Genes, Dominant; D011905:Genes, ras; D006150:Guanine Nucleotides / Q000378:metabolism; D008540:Meiosis; D008565:Membrane Proteins / Q000378:metabolism; D015689:Oncogene Protein p21(ras) / Q000378:metabolism; D009865:Oocytes; D017354:Point Mutation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf; D016283:Proto-Oncogene Proteins p21(ras) / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins; D014982:Xenopus laevis; D020703:ras GTPase-Activating Proteins
chemical_list: D020690:GTPase-Activating Proteins; D006150:Guanine Nucleotides; D008565:Membrane Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D020703:ras GTPase-Activating Proteins; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D015689:Oncogene Protein p21(ras); D016283:Proto-Oncogene Proteins p21(ras)