<p>Diaphanous-related formins (Drfs) are a family of formin homology (FH) proteins that act as effectors of Rho small GTPases during growth factor-induced cytoskeletal remodelling, stress fibre formation, and cell division [<cite idref="PUB00014909"/>]. Drf proteins are characterised by a variety of shared domains: an N-terminal GTPase-binding domain (GBD), formin-homology domains FH1, FH2 (<db_xref db="INTERPRO" dbkey="IPR003104"/>) and FH3 (<db_xref db="INTERPRO" dbkey="IPR010472"/>), and a C-terminal conserved Dia-autoregulatory domain (DAD) that binds the GBD.</p><p>This entry represents the GBD, which is a bifunctional autoinhibitory domain that interacts with and is regulated by activated Rho family members. Mammalian Drf3 contains a CRIB-like motif within its GBD for binding to Cdc42, which is required for Cdc42 to activate and guide Drf3 towards the cell cortex where it remodels the actin skeleton [<cite idref="PUB00012332"/>].</p>