Carboxyl Methylation of Ras Regulates Membrane Targeting and Effector Engagement
| Autor: | Guoming Ou, Kristina Loukeris, Michael H. Pillinger, Heidi H. Wiener, Vi K. Chiu, Victoria Dinsell, Mark R. Philips, Joseph Silletti |
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| Rok vydání: | 2004 |
| Předmět: |
MAPK/ERK pathway
Time Factors Methyltransferase CD8 Antigens Green Fluorescent Proteins Biology Transfection Methylation Biochemistry Cell Line Dogs Epidermal growth factor Anti-apoptotic Ras signalling cascade Animals Enzyme Inhibitors Phosphorylation Molecular Biology Dose-Response Relationship Drug Effector Cell Membrane fungi Cell Biology Molecular biology Acetylcysteine Protein Structure Tertiary Enzyme Activation Proto-Oncogene Proteins c-raf Luminescent Proteins Cytosol COS Cells ras Proteins Mitogen-Activated Protein Kinases Plasmids Protein Binding |
| Zdroj: | Journal of Biological Chemistry. 279:7346-7352 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m311602200 |
| Popis: | Post-translational modification of Ras proteins includes prenylcysteine-directed carboxyl methylation. Because Ras participates in Erk activation by epidermal growth factor (EGF), we tested whether Ras methylation regulates Erk activation. EGF stimulation of Erk was inhibited by AFC (N-acetyl-S-farnesyl-L-cysteine), an inhibitor of methylation, but not AGC (N-acetyl-S-geranyl-L-cysteine), an inactive analog of AFC. AFC inhibited Ras methylation as well as the activation of pathway enzymes between Ras and Erk but did not inhibit EGF receptor phosphorylation, confirming action at the level of Ras. Transient transfection of human prenylcysteine-directed carboxyl methyltransferase increased EGF-stimulated Erk activation. AFC but not AGC inhibited movement of transiently transfected green fluorescent protein-Ras from the cytosol to the plasma membrane of COS-1 cells and depleted green fluorescent protein-Ras from the plasma membrane in stably transfected Madin-Darby canine kidney cells, suggesting that methylation regulates Erk by ensuring proper membrane localization of Ras. However, when COS-1 cells were transfected with Ras complexed to CD8, plasma membrane localization of Ras was unaffected by AFC, yet EGF-stimulated Erk activation was inhibited by AFC. Thus, Ras methylation appears to regulate Erk activation both through the localization of Ras as well as the propagation of Ras-dependent signals. |
| Databáze: | OpenAIRE |
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