Dock6

Dock6 ( D edicator o f c yto k inesis 6), also known as Zir1 is a large (~200 kDa) is_associated_with::protein involved in is_associated_with::intracellular signalling networks. It is a member of the DOCK-C subfamily of the DOCK family of is_associated_with::guanine nucleotide exchange factors which function as activators of small is_associated_with::G proteins.

Discovery
Dock6 was identified as one of a family of proteins which share high is_associated_with::sequence similarity with is_associated_with::Dock180, the archetypal member of the DOCK family. It has a similar domain arrangement to other DOCK proteins, with a is_associated_with::DHR1 domain known in other proteins to bind is_associated_with::phospholipids, and a is_associated_with::DHR2 domain containing the GEF activity.

Function
There is currently very little information about the cellular role of this protein. Interestingly, however, Dock6 has been reported to exhibit dual GEF specificity towards the small G proteins is_associated_with::Rac1 and is_associated_with::Cdc42. It is the only DOCK family member reported to activate both of these G proteins. The same study also showed that is_associated_with::transfection of the Dock6 DHR2 domain into N1E-115 is_associated_with::neuroblastoma cells promoted Rac- and Cdc42-dependent is_associated_with::neurite outgrowth, although the physiological significance of this has yet to be demonstrated.