Ubiquitin-mediated regulation of RhoGTPase signalling: IAPs and HACE1 enter the fray

Abstract

Activation of members of the Rho-like family of guanosine triphosphatases GTPases (RhoGTPases) controls diverse physiological processes and is frequently found in cancer, contributing to tumour malignancy, cancer cell migration, invasion and metastasis. While the regulation of nucleotide binding to RhoGTPases is well understood, little is currently known regarding the molecular mechanisms through which RhoGTPase signalling is regulated by ubiquitylation. Two reports in this issue of The EMBO Journal and Developmental Cell now identify inhibitor of apoptosis (IAP) proteins and HACE1 as E3 ubiquitin (Ub)-protein ligases for Rac1 regulating Rac1 levels and activity.