Mapping of the p56lck-mediated phosphorylation of GAP and analysis of its influence on p21ras-GTPase activity in vitro
| Autor: | Willi Bannwarth, Hans-Werner Lahm, J. E. Scheffler, Juliette Molnos, Paul Burn, Nicholas Flint, Kurt Amrein, Baerbel Panholzer |
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| Rok vydání: | 1994 |
| Předmět: |
Gene Expression
Protein tyrosine phosphatase GTPase Biology SH2 domain Peptide Mapping Receptor tyrosine kinase GTP Phosphohydrolases Proto-Oncogene Proteins p21(ras) chemistry.chemical_compound Mice Proto-Oncogene Proteins Animals Phosphorylation Molecular Biology Binding Sites GTPase-Activating Proteins Proteins hemic and immune systems Tyrosine phosphorylation Cell Biology 3T3 Cells Cell biology Enzyme Activation chemistry Lymphocyte Specific Protein Tyrosine Kinase p56(lck) ras GTPase-Activating Proteins biology.protein Tyrosine Tyrosine kinase Proto-oncogene tyrosine-protein kinase Src Signal Transduction |
| Zdroj: | Biochimica et biophysica acta. 1222(3) |
| ISSN: | 0006-3002 |
| Popis: | The protein tyrosine kinase p56lck and other members of the src family can transduce signals from activated cell-surface receptors. As we showed earlier the GTPase-activating protein (GAP), a regulator of p21ras, is a substrate of p56lck. Here, tryptic peptides of p56lck-phosphorylated GAP were generated and analyzed by two-dimensional thin layer chromatography and mass spectroscopy. Results revealed that p56lck phosphorylates GAP specifically on Tyr-460 in vitro and in vivo. The effect of tyrosine phosphorylation of GAP on its GTPase-activating activity versus p21ras was then tested using a p21ras-dependent GTPase assay system. Our results demonstrate that p56lck-mediated tyrosine phosphorylation of GAP is not sufficient to change directly its effect on the intrinsic GTPase activity of p21ras. |
| Databáze: | OpenAIRE |
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