Related Experiment Video
Updated: Aug 17, 2026

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
Published on: March 9, 2012
Activation of Rac1 by a Crk SH3-binding protein, DOCK180
E Kiyokawa1, Y Hashimoto, S Kobayashi
1Department of Pathology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Abstract:
DOCK180 is involved in integrin signaling through CrkII-p130(Cas) complexes. We have studied the involvement of DOCK180 in Rac1 signaling cascades. DOCK180 activated JNK in a manner dependent on Rac1, Cdc42Hs, and SEK, and overexpression of DOCK180 increased the amount of GTP-bound Rac1 in 293T cells. Coexpression of CrkII and p130(Cas) enhanced this DOCK180-dependent activation of Rac1. Furthermore, we observed direct binding of DOCK180 to Rac1, but not to RhoA or Cdc42Hs. Dominant-negative Rac1 suppressed DOCK180-induced membrane spreading. These results strongly suggest that DOCK180 is a novel activator of Rac1 and involved in integrin signaling.
Related Concept Videos
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Mechanism of Lamellipodia Formation
Cell Polarization by Rho Proteins
Rab Cascades
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Intracellular Signaling Affects Focal Adhesions
Some...

