Abstract
Ral GDP dissociation stimulator (RalGDS) and RalGDS like (RGL) are putative effector proteins of Ras and contain the Ras-interacting domain (RID) at their C-terminal regions. v-Ras is known to activate c-fos promoter/enhancer and Raf-1 and to transform NIH3T3 cells. It is also known that v-Raf activates c-fos promoter/enhancer and transforms NIH3T3 cells. In this study, we examined the effect of RID on the phenotype of the cells transformed by v-Ras and v-Raf. Overexpression of RID greatly reduced cell growth in low serum, colony-forming activity in soft agar, c-fos promoter/enhancer activity, and Raf-1 activity of v-Ras-transformed cells. However, overexpression of RID did not affect the phenotype of v-Raf-transformed cells. These results clearly indicate that RID of RGL specifically binds to Ras in mammalian cells, that it blocks the signal from Ras to Raf-1, and that it reverses v-Ras-induced malignant phenotype. It has been reported that Ras-binding domains of Raf-1 and neurofibromatosis type 1 (NF1) reverse v-Ras-induced malignant phenotype. Since there is no homology in primary structures of RGL, Raf-1, and NF1, there may be a similarity of secondary or tertiary structure among RID of RGL and Ras-binding domains of Raf-1 and NF1, and the structure might be useful for developing a potential medicine for human cancers caused by Ras.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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3T3 Cells
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Alkyl and Aryl Transferases*
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Amino Acid Sequence
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Animals
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Binding Sites
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Cell Adhesion
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Cell Division
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Cell Transformation, Neoplastic / genetics*
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Cell Transformation, Neoplastic / metabolism
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Enhancer Elements, Genetic
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Farnesyltranstransferase
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GTP-Binding Proteins / chemistry
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GTP-Binding Proteins / physiology*
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Gene Expression Regulation, Neoplastic*
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Genes, Neurofibromatosis 1
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Genes, fos
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Genes, ras
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Guanine Nucleotide Exchange Factors*
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Mice
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Molecular Sequence Data
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Neoplasm Proteins / antagonists & inhibitors
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Oncogene Protein p21(ras) / antagonists & inhibitors
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Oncogene Protein p21(ras) / physiology*
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Oncogene Proteins v-raf
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Peptide Fragments / biosynthesis
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Peptide Fragments / genetics
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Promoter Regions, Genetic
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Protein Serine-Threonine Kinases / physiology*
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Proto-Oncogene Proteins / physiology*
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Proto-Oncogene Proteins c-raf
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Recombinant Proteins / metabolism
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Retroviridae Proteins, Oncogenic / physiology
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Structure-Activity Relationship
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Transferases / antagonists & inhibitors
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ral GTP-Binding Proteins
Substances
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Guanine Nucleotide Exchange Factors
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Neoplasm Proteins
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Peptide Fragments
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Proto-Oncogene Proteins
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RGL1 protein, human
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Recombinant Proteins
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Retroviridae Proteins, Oncogenic
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Rgl1 protein, mouse
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Transferases
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Alkyl and Aryl Transferases
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Farnesyltranstransferase
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Oncogene Proteins v-raf
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Protein Serine-Threonine Kinases
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Proto-Oncogene Proteins c-raf
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GTP-Binding Proteins
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Oncogene Protein p21(ras)
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ral GTP-Binding Proteins