Article abstract
Nature Cell Biology 4, 639 - 647 (2002)
Published online: 31 July 2002 | doi:10.1038/ncb835
Zizimin1, a novel Cdc42 activator, reveals a new GEF domain for Rho proteins
Nahum Meller1, Mohammad Irani-Tehrani1, William B. Kiosses1, Miguel A. Del Pozo1 & Martin A. Schwartz1
Abstract
The Rho family GTPases Rac, Rho and Cdc42 are critical in regulating the actin-based cytoskeleton, cell migration, growth, survival and gene expression. These GTPases are activated by guanine nucleotide-exchange factors (GEFs). A biochemical search for Cdc42 activators led to the cloning of zizimin1, a new protein whose overexpression induces Cdc42 activation. Sequence comparison combined with mutational analysis identified a new domain, which we named CZH2, that mediates direct interaction with Cdc42. CZH2-containing proteins constitute a new superfamily that includes the so-called 'CDM' proteins that bind to and activate Rac. Together, the results suggest that CZH2 is a new GEF domain for the Rho family of proteins.
- Division of Vascular Biology, Department of Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla CA 92037, USA
Correspondence to: Martin A. Schwartz1 e-mail: schwartz@scripps.edu
