Dedicator Of Cytokinesis 1 (DOCK1)

Dock180 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.Dock180 and related proteins differ from other GEFs in that they do not possess the canonical structure of tandem DH-PH domains known to elicit nucleotide exchange. Instead they possess a DHR2 domain which mediates Rac activation by stabilising it in its nucleotide-free state. Dock180 was identified, using a far-western blotting approach, as a binding partner of the adaptor protein Crk that was able to induce morphological changes in 3T3 fibroblasts.