Systems analysis of RhoGEF and RhoGAP regulatory proteins reveals spatially organized RAC1 signalling from integrin adhesions

Nat Cell Biol. 2020 Apr;22(4):498-511. doi: 10.1038/s41556-020-0488-x. Epub 2020 Mar 23.


Rho GTPases are central regulators of the cytoskeleton and, in humans, are controlled by 145 multidomain guanine nucleotide exchange factors (RhoGEFs) and GTPase-activating proteins (RhoGAPs). How Rho signalling patterns are established in dynamic cell spaces to control cellular morphogenesis is unclear. Through a family-wide characterization of substrate specificities, interactomes and localization, we reveal at the systems level how RhoGEFs and RhoGAPs contextualize and spatiotemporally control Rho signalling. These proteins are widely autoinhibited to allow local regulation, form complexes to jointly coordinate their networks and provide positional information for signalling. RhoGAPs are more promiscuous than RhoGEFs to confine Rho activity gradients. Our resource enabled us to uncover a multi-RhoGEF complex downstream of G-protein-coupled receptors controlling CDC42-RHOA crosstalk. Moreover, we show that integrin adhesions spatially segregate GEFs and GAPs to shape RAC1 activity zones in response to mechanical cues. This mechanism controls the protrusion and contraction dynamics fundamental to cell motility. Our systems analysis of Rho regulators is key to revealing emergent organization principles of Rho signalling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • COS Cells
  • Cell Adhesion
  • Cell Line
  • Cell Movement
  • Chlorocebus aethiops
  • Computational Biology
  • Cytoskeleton / genetics*
  • Cytoskeleton / metabolism
  • Cytoskeleton / ultrastructure
  • Dogs
  • Fibroblasts / metabolism
  • Fibroblasts / ultrastructure
  • GTPase-Activating Proteins / classification
  • GTPase-Activating Proteins / genetics*
  • GTPase-Activating Proteins / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Integrins / genetics*
  • Integrins / metabolism
  • Madin Darby Canine Kidney Cells
  • Mechanotransduction, Cellular / genetics*
  • Mice
  • Pan troglodytes
  • Protein Domains
  • Rats
  • Rho Guanine Nucleotide Exchange Factors / classification
  • Rho Guanine Nucleotide Exchange Factors / genetics*
  • Rho Guanine Nucleotide Exchange Factors / metabolism
  • rac1 GTP-Binding Protein / genetics*
  • rac1 GTP-Binding Protein / metabolism


  • GTPase-Activating Proteins
  • Integrins
  • RAC1 protein, human
  • Rho Guanine Nucleotide Exchange Factors
  • rac1 GTP-Binding Protein