DOCK9
Description
The DOCK9 (dedicator of cytokinesis 9) is a protein-coding gene located on chromosome 13.
Dedicator of cytokinesis protein 9 (DOCK9), also known as Zizimin1, is a large (~230 kDa) protein encoded in the human by the DOCK9 gene, involved in intracellular signalling networks. It is a member of the DOCK-D subfamily of the DOCK family of guanine nucleotide exchange factors that function as activators of small G-proteins. Dock9 activates the small G protein Cdc42.
Dock9 was discovered using an affinity proteomic approach designed to identify novel activators of the small G protein Cdc42 in fibroblasts. Subsequent northern blot analysis revealed that Dock9 is expressed primarily in the brain, heart, skeletal muscle, kidney, placenta and lung. Lower levels were detected in the colon, thymus, liver, small intestine and in leukocytes from peripheral blood.
Dock9 shares a similar structure of two core domains (known as DHR1 and DHR2), which are shared by all DOCK family members. The C-terminal DHR2 domain functions as an atypical GEF domain for small G proteins (see Dock180: structure and function) and the DHR1 domain is known, in some DOCK-A/B/C subfamily proteins, to be involved in their recruitment to the plasma membrane. Unlike DOCK-A/B/C proteins DOCK-D proteins (including Dock9) contain an N-terminal pleckstrin homology (PH) domain that mediates their recruitment to the membrane. Dock9, along with other DOCK-C/D subfamily members, can activate Cdc42 in vitro and in vivo via its DHR2 domain.
DOCK9 is also known as ZIZ1, ZIZIMIN1.
