| Structural highlights
Function
CUL4A_HUMAN Core component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes which mediate the ubiquitination and subsequent proteasomal degradation of target proteins. As a scaffold protein may contribute to catalysis through positioning of the substrate and the ubiquitin-conjugating enzyme. The E3 ubiquitin-protein ligase activity of the complex is dependent on the neddylation of the cullin subunit and is inhibited by the association of the deneddylated cullin subunit with TIP120A/CAND1. The functional specificity of the E3 ubiquitin-protein ligase complex depends on the variable substrate recognition component. DCX(DET1-COP1) directs ubiquitination of JUN. DCX(DDB2) directs ubiquitination of XPC. In association with RBX1, DDB1 and DDB2 is required for histone H3 and histone H4 ubiquitination in response to ultraviolet and may be important for subsequent DNA repair. DCX(DTL) plays a role in PCNA-dependent polyubiquitination of CDT1 and MDM2-dependent ubiquitination of TP53 in response to radiation-induced DNA damage and during DNA replication. In association with DDB1 and SKP2 probably is involved in ubiquitination of CDKN1B/p27kip. Is involved in ubiquitination of HOXA9.[1] [2] [3] [4] [5] [6]
References
- ↑ Higa LA, Mihaylov IS, Banks DP, Zheng J, Zhang H. Radiation-mediated proteolysis of CDT1 by CUL4-ROC1 and CSN complexes constitutes a new checkpoint. Nat Cell Biol. 2003 Nov;5(11):1008-15. Epub 2003 Oct 26. PMID:14578910 doi:10.1038/ncb1061
- ↑ Zhang Y, Morrone G, Zhang J, Chen X, Lu X, Ma L, Moore M, Zhou P. CUL-4A stimulates ubiquitylation and degradation of the HOXA9 homeodomain protein. EMBO J. 2003 Nov 17;22(22):6057-67. PMID:14609952 doi:https://dx.doi.org/10.1093/emboj/cdg577
- ↑ Nag A, Bagchi S, Raychaudhuri P. Cul4A physically associates with MDM2 and participates in the proteolysis of p53. Cancer Res. 2004 Nov 15;64(22):8152-5. PMID:15548678 doi:https://dx.doi.org/10.1158/0008-5472.CAN-04-2598
- ↑ Hu J, McCall CM, Ohta T, Xiong Y. Targeted ubiquitination of CDT1 by the DDB1-CUL4A-ROC1 ligase in response to DNA damage. Nat Cell Biol. 2004 Oct;6(10):1003-9. Epub 2004 Sep 26. PMID:15448697 doi:10.1038/ncb1172
- ↑ Wang H, Zhai L, Xu J, Joo HY, Jackson S, Erdjument-Bromage H, Tempst P, Xiong Y, Zhang Y. Histone H3 and H4 ubiquitylation by the CUL4-DDB-ROC1 ubiquitin ligase facilitates cellular response to DNA damage. Mol Cell. 2006 May 5;22(3):383-94. PMID:16678110 doi:S1097-2765(06)00230-9
- ↑ Bondar T, Kalinina A, Khair L, Kopanja D, Nag A, Bagchi S, Raychaudhuri P. Cul4A and DDB1 associate with Skp2 to target p27Kip1 for proteolysis involving the COP9 signalosome. Mol Cell Biol. 2006 Apr;26(7):2531-9. PMID:16537899 doi:https://dx.doi.org/26/7/2531
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