The efficacy of Raf kinase recruitment to the GTPase H-ras depends on H-ras membrane conformer-specific nanoclustering

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Camilo Guzmán, Maja Šolman, Alessio Ligabue, Olga Blaževitš, Débora M Andrade, Luc Reymond, Christian Eggeling, Daniel Abankwa
Publisher: ASBMB
Publication year: 2014
Journal: Journal of Biological Chemistry
Journal acronym: JBC
Volume number: 289
Issue number: 14
Start page: 9519
End page: 9533
eISSN: 1083-351X


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 nanocluster, 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 α4- 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 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.

Last updated on 2020-19-01 at 02:46