Abstract
Significance: RAS proteins, critical regulators of cell growth and differentiation, are the most frequently mutated oncogenes in humans. RAS functions as dimers/coclusters on cell membranes. We developed an improved split luciferase complementation assay coupled to a powerful genetic system to show that colocalization within the same membrane domain enables formation of RAS dimers/coclusters with itself and other membrane-associated proteins. Membrane association-facilitated interactions (MAFIs) are not sufficient for RBD-mediated Ras inhibition, which additionally requires high-affinity domain-mediated interactions. Notably, we show that MAFI augments the impact of domain-mediated interactions to elicit autophagy/lysosome-mediated elimination of nonfunctional RAS complexes. This broadly applicable strategy enables discovery of low-affinity protein interactions mediated by membrane tethering and analysis of their impact on biologic function.
All Related Versions
Funding Information
  • Susan G. Komen Foundation (SAC110036)
  • HHS | NIH | National Cancer Institute (R35CA197687)
  • HHS | NIH | National Cancer Institute (R35CA197709)
  • Leona M. and Harry B. Helmsley Charitable Trust (2012-PG-MED002)
  • Freeberg Foundation (No Grant Number)
  • Private: The Greenfields (No Grant Number)
  • Sorrento Biosciences (No Grant Number)
  • Genentech (No Grant Number)