4goj

Structural highlights

Disease

[U119A_HUMAN] Idiopathic CD4 lymphocytopenia;Cone rod dystrophy. Defects in UNC119 may be a cause of cone-rod dystrophy. A mutation was found in a 57-year-old woman with late-onset cone-rod dystrophy: from 40 year old, the patient suffered from poor night vision, defective color vision and light-sensitivity. At 57 year old, she displayed reduced visual acuity, myopa, macular atrophy and pericentral ring scotomas. The disease was caused by a heterozygous mutation causing premature termination and truncated UNC119 protein with dominant-negative effect.

Function

[ARL3_MOUSE] Small GTP-binding protein which cycles between an inactive GDP-bound and an active GTP-bound form, and the rate of cycling is regulated by guanine nucleotide exchange factors (GEF) and GTPase-activating proteins (GAP). Required for normal cytokinesis and cilia signaling. Required for targeting proteins such as NPHP3 to the ciliary membrane by releasing myristoylated NPHP3 from UNC119B cargo adapter into the cilium (By similarity). Requires assistance from GTPase-activating proteins (GAPs) like RP2 and PDE6D, in order to cycle between inactive GDP-bound and active GTP-bound forms.^{[1] [2]} [U119A_HUMAN] Myristoyl-binding protein that acts as a cargo adapter: specifically binds the myristoyl moiety of a subset of N-terminally myristoylated proteins and is required for their localization. Binds myristoylated GNAT1 and is required for G-protein localization and trafficking in sensory neurons. Binds myristoylated NPHP3; however, in contrast to UNC119B, does not seem to play a major role in ciliary membrane localization of NPHP3. Does not bind all myristoylated proteins. Probably plays a role in trafficking proteins in photoreceptor cells.^{[3] [4]}

References

1. ↑ Hanzal-Bayer M, Linari M, Wittinghofer A. Properties of the interaction of Arf-like protein 2 with PDEdelta. J Mol Biol. 2005 Jul 29;350(5):1074-82. PMID:15979089 doi:10.1016/j.jmb.2005.05.036
2. ↑ Veltel S, Gasper R, Eisenacher E, Wittinghofer A. The retinitis pigmentosa 2 gene product is a GTPase-activating protein for Arf-like 3. Nat Struct Mol Biol. 2008 Apr;15(4):373-80. Epub 2008 Mar 23. PMID:18376416 doi:nsmb.1396
3. ↑ Wright KJ, Baye LM, Olivier-Mason A, Mukhopadhyay S, Sang L, Kwong M, Wang W, Pretorius PR, Sheffield VC, Sengupta P, Slusarski DC, Jackson PK. An ARL3-UNC119-RP2 GTPase cycle targets myristoylated NPHP3 to the primary cilium. Genes Dev. 2011 Nov 15;25(22):2347-60. doi: 10.1101/gad.173054.111. PMID:22085962 doi:10.1101/gad.173443.111
4. ↑ Zhang H, Constantine R, Vorobiev S, Chen Y, Seetharaman J, Huang YJ, Xiao R, Montelione GT, Gerstner CD, Davis MW, Inana G, Whitby FG, Jorgensen EM, Hill CP, Tong L, Baehr W. UNC119 is required for G protein trafficking in sensory neurons. Nat Neurosci. 2011 Jun 5. PMID:21642972 doi:10.1038/nn.2835
5. ↑ Ismail SA, Chen YX, Miertzschke M, Vetter IR, Koerner C, Wittinghofer A. Structural basis for Arl3-specific release of myristoylated ciliary cargo from UNC119. EMBO J. 2012 Oct 17;31(20):4085-94. doi: 10.1038/emboj.2012.257. Epub 2012 Sep 7. PMID:22960633 doi:http://dx.doi.org/10.1038/emboj.2012.257