Dedicator Of Cytokinesis 3 (DOCK3)

Dock3 was originally discovered in a screen for proteins that bind presenilin (a transmembrane protein which is mutated in early onset Alzheimer's disease).Dock3 is specifically expressed in neurones (primarily in the cerebral cortex and hippocampus).Dock3 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.Dock3 exhibits the same domain arrangement as Dock180 and these proteins share a considerable (40%) degree of sequence similarity.