Structural highlights
Disease
[DOCK7_HUMAN] Early-onset epileptic encephalopathy-cortical blindness-intellectual disability-facial dysmorphism syndrome. The disease is caused by mutations affecting the gene represented in this entry.
Function
[DOCK7_HUMAN] Functions as a guanine nucleotide exchange factor (GEF), which activates Rac1 and Rac3 Rho small GTPases by exchanging bound GDP for free GTP. Does not have a GEF activity for CDC42. Required for STMN1 'Ser-15' phosphorylation during axon formation and consequently for neuronal polarization (PubMed:16982419). Has a role in pigmentation (By similarity). Involved in the regulation of cortical neurogenesis through the control of radial glial cells (RGCs) proliferation versus differentiation; negatively regulates the basal-to-apical interkinetic nuclear migration of RGCs by antagonizing the microtubule growth-promoting function of TACC3 (By similarity).[UniProtKB:Q8R1A4][1] [CDC42_HUMAN] Plasma membrane-associated small GTPase which cycles between an active GTP-bound and an inactive GDP-bound state. In active state binds to a variety of effector proteins to regulate cellular responses. Involved in epithelial cell polarization processes. Regulates the bipolar attachment of spindle microtubules to kinetochores before chromosome congression in metaphase. Plays a role in the extension and maintenance of the formation of thin, actin-rich surface projections called filopodia. Mediates CDC42-dependent cell migration.[2] [3] [4]
Publication Abstract from PubMed
The Dedicator Of CytoKinesis (DOCK) family of atypical guanine nucleotide exchange factors activates the Rho family GTPases Rac and/or Cdc42 through DOCK homology region 2 (DHR-2). Previous structural analyses of the DHR-2 domains of DOCK2 and DOCK9 have shown that they preferentially bind Rac1 and Cdc42, respectively; however, the molecular mechanism by which DHR-2 distinguishes between these GTPases is unclear. Here we report the crystal structure of the Cdc42-bound form of the DOCK7 DHR-2 domain showing dual specificity for Rac1 and Cdc42. The structure revealed increased substrate tolerance of DOCK7 at the interfaces with switch 1 and residue 56 of Cdc42. Furthermore, molecular dynamics simulations showed a closed-to-open conformational change in the DOCK7 DHR-2 domain between the Cdc42- and Rac1-bound states by lobe B displacement. Our results suggest that lobe B acts as a sensor for identifying different switch 1 conformations and explain how DOCK7 recognizes both Rac1 and Cdc42.
Structural Basis for the Dual Substrate Specificity of DOCK7 Guanine Nucleotide Exchange Factor.,Kukimoto-Niino M, Tsuda K, Ihara K, Mishima-Tsumagari C, Honda K, Ohsawa N, Shirouzu M Structure. 2019 Feb 16. pii: S0969-2126(19)30045-0. doi:, 10.1016/j.str.2019.02.001. PMID:30853411[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Watabe-Uchida M, John KA, Janas JA, Newey SE, Van Aelst L. The Rac activator DOCK7 regulates neuronal polarity through local phosphorylation of stathmin/Op18. Neuron. 2006 Sep 21;51(6):727-39. PMID:16982419 doi:http://dx.doi.org/S0896-6273(06)00585-X
- ↑ Gauthier-Campbell C, Bredt DS, Murphy TH, El-Husseini Ael-D. Regulation of dendritic branching and filopodia formation in hippocampal neurons by specific acylated protein motifs. Mol Biol Cell. 2004 May;15(5):2205-17. Epub 2004 Feb 20. PMID:14978216 doi:10.1091/mbc.E03-07-0493
- ↑ Oceguera-Yanez F, Kimura K, Yasuda S, Higashida C, Kitamura T, Hiraoka Y, Haraguchi T, Narumiya S. Ect2 and MgcRacGAP regulate the activation and function of Cdc42 in mitosis. J Cell Biol. 2005 Jan 17;168(2):221-32. Epub 2005 Jan 10. PMID:15642749 doi:10.1083/jcb.200408085
- ↑ Modzelewska K, Newman LP, Desai R, Keely PJ. Ack1 mediates Cdc42-dependent cell migration and signaling to p130Cas. J Biol Chem. 2006 Dec 8;281(49):37527-35. Epub 2006 Oct 12. PMID:17038317 doi:10.1074/jbc.M604342200
- ↑ Kukimoto-Niino M, Tsuda K, Ihara K, Mishima-Tsumagari C, Honda K, Ohsawa N, Shirouzu M. Structural Basis for the Dual Substrate Specificity of DOCK7 Guanine Nucleotide Exchange Factor. Structure. 2019 Feb 16. pii: S0969-2126(19)30045-0. doi:, 10.1016/j.str.2019.02.001. PMID:30853411 doi:http://dx.doi.org/10.1016/j.str.2019.02.001
