Molecular Cell
Volume 1, Issue 2, January 1998, Pages 183-192
Journal home page for Molecular Cell

Article
PAK Kinases Are Directly Coupled to the PIX Family of Nucleotide Exchange Factors

https://doi.org/10.1016/S1097-2765(00)80019-2Get rights and content
Under an Elsevier user license
open archive

Abstract

The PAK family of kinases are regulated through interaction with the small GTPases Cdc42 and Rac1, but little is known of the signaling components immediately upstream or downstream of these proteins. We have purified and cloned a new class of Rho-p21 guanine nucleotide exchange factor binding tightly through its N-terminal SH3 domain to a conserved proline-rich PAK sequence with a Kd of 24 nM. This PAK-interacting exchange factor (PIX), which is widely expressed and enriched in Cdc42- and Rac1-driven focal complexes, is required for PAK recruitment to these sites. PIX can induce membrane ruffling, with an associated activation of Rac1. Our results suggest a role for PIX in Cdc42-to-Rac1 signaling, involving the PIX/PAK complex.

Cited by (0)