The efficacy of Raf kinase recruitment to the GTPase H-ras depends on H-ras membrane conformer-specific nanoclustering
| Autor: | Luc Reymond, Daniel Abankwa, Debora M. Andrade, Camilo Guzmán, Maja Šolman, Christian Eggeling, Olga Blaževitš, Alessio Ligabue |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Nanocluster
Galectin 1 Mutant Stimulated Emission Depletion (STED) GTPase Biology Oncogene Protein p21(ras) ta3111 Biochemistry Models Biological Protein Structure Secondary Cell Line Fluorescence-lifetime Microscopy Imaging (FLIM) Cell membrane Mice Cricetinae Neoplasms Fluorescence Correlation Spectroscopy medicine Animals Molecular Biology Cancer Mice Knockout Effector Cell Membrane ta1182 Membrane Cell Biology Signaling Cell biology medicine.anatomical_structure Cytoplasm Galectin-1 raf Kinases Fluorescence Recovery after Photobleaching (FRAP) Signal transduction Protein Multimerization Fluorescence Resonance Energy Transfer (FRET) Ras Signal Transduction |
| Zdroj: | The Journal of Biological Chemistry |
| Popis: | Background: Ras nanoclusters contain 6-8 Ras proteins on the plasma membrane and serve as indispensable signaling platforms for Ras-MAPK signaling. Results: Ras membrane conformer mutants impart specific galectin-1-dependent nanoclustering responses. Conclusion: Mutations in Ras can affect its nanoclustering response and thus allosterically effector recruitment and downstream signaling. Significance: Disease-associated mutations that perturb Ras membrane conformers may alter signaling through nanoclustering. Solution structures and biochemical data have provided a wealth of mechanistic insight into Ras GTPases. However, information on how much the membrane organization of these lipid-modified proteins impacts on their signaling is still scarce. Ras proteins are organized into membrane nanoclusters, which are necessary for Ras-MAPK signaling. Using quantitative conventional and super-resolution fluorescence methods, as well as mathematical modeling, we investigated nanoclustering of H-ras helix 4 and hypervariable region mutants that have different bona fide conformations on the membrane. By following the emergence of conformer-specific nanoclusters in the plasma membrane of mammalian cells, we found that conformers impart distinct nanoclustering responses depending on the cytoplasmic levels of the nanocluster scaffold galectin-1. Computational modeling revealed that complexes containing H-ras conformers and galectin-1 affect both the number and lifetime of nanoclusters and thus determine the specific Raf effector recruitment. Our results show that mutations in Ras can affect its nanoclustering response and thus allosterically effector recruitment and downstream signaling. We postulate that cancer- and developmental disease-linked mutations that are associated with the Ras membrane conformation may exhibit so far unrecognized Ras nanoclustering and therefore signaling alterations. |
| Databáze: | OpenAIRE |
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