?
Dock Homology Region 2, a GEF domain, of Class A Dedicator of Cytokinesis 1 Dock1, also called Dock180, is an atypical guanine nucleotide exchange factor (GEF) that lacks the conventional Dbl homology (DH) domain. As a GEF, it activates small GTPases by exchanging bound GDP for free GTP. Dock1 interacts with the scaffold protein Elmo and the resulting complex functions upstream of Rac in many biological events including phagocytosis of apoptotic cells, cell migration and invasion. In the nervous system, it mediates attractive responses to netrin-1 and thus, plays a role in axon outgrowth and pathfinding. DOCK proteins are divided into four classes (A-D) based on sequence similarity and domain architecture; class A includes Dock1, 2 and 5. All DOCKs contain two homology domains: the DHR-1 (Dock homology region-1), also called CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and DHR-2 (also called CZH2 or Docker). The DHR-1 domain binds phosphatidylinositol-3,4,5-triphosphate. This alignment model represents the DHR-2 domain of Dock1, which contains the catalytic GEF activity for Rac and/or Cdc42. Class A DOCKs, like Dock1, are specific GEFs for Rac and they contain an SH3 domain at the N-terminal region and a PxxP motif at the C-terminus. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",