Wnt-1 responsive Cdc42 homolog (Wrch-1) is a Rho family GTPase similar to Cdc42. Wrch-1 (Wnt-1 responsive Cdc42 homolog) is a Rho family GTPase that shares significant sequence and functional similarity with Cdc42. Wrch-1 was first identified in mouse mammary epithelial cells, where its transcription is upregulated in Wnt-1 transformation. Wrch-1 contains N- and C-terminal extensions relative to cdc42, suggesting potential differences in cellular localization and function. The Wrch-1 N-terminal extension contains putative SH3 domain-binding motifs and has been shown to bind the SH3 domain-containing protein Grb2, which increases the level of active Wrch-1 in cells. Unlike Cdc42, which localizes to the cytosol and perinuclear membranes, Wrch-1 localizes extensively with the plasma membrane and endosomes. The membrane association, localization, and biological activity of Wrch-1 indicate an atypical model of regulation distinct from other Rho family GTPases. Most Rho proteins contain a lipid modification site at the C-terminus, with a typical sequence motif CaaX, where a = an aliphatic amino acid and X = any amino acid. Lipid binding is essential for membrane attachment, a key feature of most Rho proteins. Due to the presence of truncated sequences in this CD, the lipid modification site is not available for annotation.

Protein of unknown function (DUF563). Family of uncharacterized proteins.