Dedicator Of Cytokinesis 4 (DOCK4)

Dock4 is part of a large class of proteins (GEFs) which contibrute to cellular signalling events by activating small G proteins. In their resting state G proteins are bound to Guanosine diphosphate (GDP) and their activation requires the dissociation of GDP and binding of guanosine triphosphate (GTP). GEFs activate G proteins by promoting this nucleotide exchange.The domain arrangement of Dock4 is largely equivalent to that of Dock180 (the archetypal member of the DOCK family) and other DOCK-A/B family members (35% sequence identity with Dock180, 39% with Dock2 and 54% with Dock3). Dock4, however, contains a unique set of motifs at its proline-rich C-terminus which include a Src-binding site that is shared with CED-5, the C. elegans ortholog of mammalian DOCK proteins.