Electrostatic Interactions Positively Regulate K-Ras Nanocluster Formation and Function
- 1 July 2008
- journal article
- Published by Taylor & Francis in Molecular and Cellular Biology
- Vol. 28 (13) , 4377-4385
- https://doi.org/10.1128/mcb.00050-08
Abstract
The organization of Ras proteins into plasma membrane nanoclusters is essential for high-fidelity signal transmission, but whether the nanoscale environments of different Ras nanoclusters regulate effector interactions is unknown. We show using high-resolution spatial mapping that Raf-1 is recruited to and retained in K-Ras-GTP nanoclusters. In contrast, Raf-1 recruited to the plasma membrane by H-Ras is not retained in H-Ras-GTP nanoclusters. Similarly, upon epidermal growth factor receptor activation, Raf-1 is preferentially recruited to K-Ras-GTP and not H-Ras-GTP nanoclusters. The formation of K-Ras-GTP nanoclusters is inhibited by phosphorylation of S181 in the C-terminal polybasic domain or enhanced by blocking S181 phosphorylation, with a concomitant reduction or increase in Raf-1 plasma membrane recruitment, respectively. Phosphorylation of S181 does not, however, regulate in vivo interactions with the nanocluster scaffold galectin-3 (Gal3), indicating separate roles for the polybasic domain and Gal3 in driving K-Ras nanocluster formation. Together, these data illustrate that Ras nanocluster composition regulates effector recruitment and highlight the importance of lipid/protein nanoscale environments to the activation of signaling cascades.Keywords
This publication has 30 references indexed in Scilit:
- K-ras4B and Prenylated Proteins Lacking “Second Signals” Associate Dynamically with Cellular MembranesMolecular Biology of the Cell, 2006
- Ras plasma membrane signalling platformsBiochemical Journal, 2005
- The RAF proteins take centre stageNature Reviews Molecular Cell Biology, 2004
- Three Separable Domains Regulate GTP-Dependent Association of H-ras with the Plasma MembraneMolecular and Cellular Biology, 2004
- Single‐ and Multiple‐Molecule Dynamics of the Signaling from H‐Ras to cRaf‐1 Visualized on the Plasma Membrane of Living CellsChemphyschem, 2003
- Lateral Sequestration of Phosphatidylinositol 4,5-Bisphosphate by the Basic Effector Domain of Myristoylated Alanine-rich C Kinase Substrate Is Due to Nonspecific Electrostatic InteractionsJournal of Biological Chemistry, 2002
- A comparison between parametric and non-parametric approaches to the analysis of replicated spatial point patternsAdvances in Applied Probability, 2000
- Quantitative Analysis of the Complex between p21 and the Ras-binding Domain of the Human Raf-1 Protein KinaseJournal of Biological Chemistry, 1995
- Requirement for Ras in Raf activation is overcome by targeting Raf to the plasma membraneNature, 1994
- The cytoplasmic protein GAP is implicated as the target for regulation by the ras gene productNature, 1988