Involvement of the switch 2 domain of Ras in its interaction with guanine nucleotide exchange factors
| Autor: | Channing J. Der, Jonelle K. Drugan, Amy Lowry, Jaewon Han, Dan Broek, Sharon L. Campbell, Lawrence A. Quilliam, Raymond D. Mosteller, Mark M. Hisaka, Sheng Zhong |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Transcriptional Activation
Magnetic Resonance Spectroscopy Recombinant Fusion Proteins Mutant Cell Cycle Proteins medicine.disease_cause Biochemistry Guanosine Diphosphate 3T3 cells Protein Structure Secondary Fungal Proteins Mice GTP-Binding Proteins medicine Escherichia coli Phosphoprotein Phosphatases Animals Humans Point Mutation Nucleotide Cloning Molecular PLCG1 Molecular Biology chemistry.chemical_classification Mammals Mutation Binding Sites ras-GRF1 GTPase-Activating Proteins Proteins Cell Biology 3T3 Cells Cell biology Models Structural Repressor Proteins Transformation (genetics) Kinetics medicine.anatomical_structure Cell Transformation Neoplastic Genes ras chemistry ras GTPase-Activating Proteins SOS1 Mutagenesis Site-Directed ras Proteins Guanine nucleotide exchange factor Guanosine Triphosphate SOS1 Protein |
| Zdroj: | The Journal of biological chemistry. 271(19) |
| ISSN: | 0021-9258 |
| Popis: | While Ras proteins are activated by stimulated GDP release, which enables acquisition of the active GTP-bound state, little is known about how guanine nucleotide exchange factors (GEFs) interact with Ras to promote this exchange reaction. Here we report that mutations within the switch 2 domain of Ras (residues 62-69) inhibit activation of Ras by the mammalian GEFs, Sos1, and GRF/CDC25Mm. While mutations in the 62-69 region blocked upstream activation of Ras, they did not disrupt Ras effector functions, including transcriptional activation and transformation of NIH 3T3 cells. Biochemical analysis indicated that the loss of GEF responsiveness of a Ras(69N) mutant was due to a loss of GEF binding, with no change in intrinsic nucleotide exchange activity. Furthermore, structural analysis of Ras(69N) using NMR spectroscopy indicated that mutation of residue 69 had a very localized effect on Ras structure that was limited to alpha-helix 2 of the switch 2 domain. Together, these results suggest that the switch 2 domain of Ras forms a direct interaction with GEFs. |
| Databáze: | OpenAIRE |
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