Dynamics of Membrane-Bound G12V-KRAS from Simulations and Single-Molecule FRET in Native Nanodiscs.
Biophys J
; 116(2): 179-183, 2019 01 22.
Article
en En
| MEDLINE
| ID: mdl-30616834
ABSTRACT
Recent studies have shown that the small GTPase KRAS adopts multiple orientations with respect to the plane of anionic model membranes, whereby either the three C-terminal helices or the three N-terminal ß-strands of the catalytic domain face the membrane. This has functional implications because, in the latter, the membrane occludes the effector-interacting surface. However, it remained unclear how membrane reorientation occurs and, critically, whether it occurs in the cell in which KRAS operates as a molecular switch in signaling pathways. Herein, using data from a 20 µs-long atomistic molecular dynamics simulation of the oncogenic G12V-KRAS mutant in a phosphatidylcholine/phosphatidylserine bilayer, we first show that internal conformational fluctuations of flexible regions in KRAS result in three distinct membrane orientations. We then show, using single-molecule fluorescence resonance energy transfer measurements in native lipid nanodiscs derived from baby hamster kidney cells, that G12V-KRAS samples three conformational states that correspond to the predicted orientations. The combined results suggest that relatively small energy barriers separate orientation states and that signaling-competent conformations dominate the overall population.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Proto-Oncogénicas p21(ras)
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Simulación de Dinámica Molecular
/
Membrana Dobles de Lípidos
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Año:
2019
Tipo del documento:
Article