| Structural highlights
Disease
MDM2_HUMAN Note=Seems to be amplified in certain tumors (including soft tissue sarcomas, osteosarcomas and gliomas). A higher frequency of splice variants lacking p53 binding domain sequences was found in late-stage and high-grade ovarian and bladder carcinomas. Four of the splice variants show loss of p53 binding.
Function
MDM2_HUMAN E3 ubiquitin-protein ligase that mediates ubiquitination of p53/TP53, leading to its degradation by the proteasome. Inhibits p53/TP53- and p73/TP73-mediated cell cycle arrest and apoptosis by binding its transcriptional activation domain. Also acts as an ubiquitin ligase E3 toward itself and ARRB1. Permits the nuclear export of p53/TP53. Promotes proteasome-dependent ubiquitin-independent degradation of retinoblastoma RB1 protein. Inhibits DAXX-mediated apoptosis by inducing its ubiquitination and degradation. Component of the TRIM28/KAP1-MDM2-p53/TP53 complex involved in stabilizing p53/TP53. Also component of the TRIM28/KAP1-ERBB4-MDM2 complex which links growth factor and DNA damage response pathways. Mediates ubiquitination and subsequent proteasome degradation of DYRK2 in nucleus. Ubiquitinates IGF1R and promotes it to proteasomal degradation.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Publication Abstract from PubMed
The p53, p63, and p73 proteins belong to the p53 family of transcription factors, which play key roles in tumor suppression. Although the transactivation domains (TADs) of the p53 family are intrinsically disordered, these domains are commonly involved in the regulatory interactions with mouse double minute 2 (MDM2). In this study, we determined the solution structure of the p73TAD peptide in complex with MDM2 using NMR spectroscopy and biophysically characterized the interactions between the p53 family TAD peptides and MDM2. In combination with mutagenesis data, the complex structures revealed remarkably close mimicry of the MDM2 recognition mechanism among the p53 family TADs. Upon binding with MDM2, the intrinsically disordered p73TAD and p63TAD peptides adopt an amphipathic alpha-helical conformation, which is similar to the conformation of p53TAD, although the alpha-helical content induced by MDM2 binding varies. With isothermal titration calorimetry (ITC) and circular dichroism (CD) data, our biophysical characterization showed that p73TAD resembles p53TAD more closely than p63TAD in terms of helical stability, MDM2 binding affinity, and phosphorylation effects on MDM2 binding. Therefore, our structural information may be useful in establishing alternative anticancer strategies that exploit the activation of the p73 pathway against human tumors bearing p53 mutations.
Structural convergence of unstructured p53 family transactivation domains in MDM2 recognition.,Shin JS, Ha JH, Lee DH, Ryu KS, Bae KH, Park BC, Park SG, Yi GS, Chi SW Cell Cycle. 2015;14(4):533-43. doi: 10.1080/15384101.2014.998056. PMID:25591003[12]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Girnita L, Girnita A, Larsson O. Mdm2-dependent ubiquitination and degradation of the insulin-like growth factor 1 receptor. Proc Natl Acad Sci U S A. 2003 Jul 8;100(14):8247-52. Epub 2003 Jun 23. PMID:12821780 doi:10.1073/pnas.1431613100
- ↑ Li M, Brooks CL, Kon N, Gu W. A dynamic role of HAUSP in the p53-Mdm2 pathway. Mol Cell. 2004 Mar 26;13(6):879-86. PMID:15053880
- ↑ Bernardi R, Scaglioni PP, Bergmann S, Horn HF, Vousden KH, Pandolfi PP. PML regulates p53 stability by sequestering Mdm2 to the nucleolus. Nat Cell Biol. 2004 Jul;6(7):665-72. Epub 2004 Jun 13. PMID:15195100 doi:10.1038/ncb1147
- ↑ Sdek P, Ying H, Chang DL, Qiu W, Zheng H, Touitou R, Allday MJ, Xiao ZX. MDM2 promotes proteasome-dependent ubiquitin-independent degradation of retinoblastoma protein. Mol Cell. 2005 Dec 9;20(5):699-708. PMID:16337594 doi:10.1016/j.molcel.2005.10.017
- ↑ Brady M, Vlatkovic N, Boyd MT. Regulation of p53 and MDM2 activity by MTBP. Mol Cell Biol. 2005 Jan;25(2):545-53. PMID:15632057 doi:25/2/545
- ↑ Stevenson LF, Sparks A, Allende-Vega N, Xirodimas DP, Lane DP, Saville MK. The deubiquitinating enzyme USP2a regulates the p53 pathway by targeting Mdm2. EMBO J. 2007 Feb 21;26(4):976-86. Epub 2007 Feb 8. PMID:17290220 doi:10.1038/sj.emboj.7601567
- ↑ Chen D, Zhang J, Li M, Rayburn ER, Wang H, Zhang R. RYBP stabilizes p53 by modulating MDM2. EMBO Rep. 2009 Feb;10(2):166-72. doi: 10.1038/embor.2008.231. Epub 2008 Dec 19. PMID:19098711 doi:10.1038/embor.2008.231
- ↑ Busso CS, Iwakuma T, Izumi T. Ubiquitination of mammalian AP endonuclease (APE1) regulated by the p53-MDM2 signaling pathway. Oncogene. 2009 Apr 2;28(13):1616-25. doi: 10.1038/onc.2009.5. Epub 2009 Feb 16. PMID:19219073 doi:10.1038/onc.2009.5
- ↑ Taira N, Yamamoto H, Yamaguchi T, Miki Y, Yoshida K. ATM augments nuclear stabilization of DYRK2 by inhibiting MDM2 in the apoptotic response to DNA damage. J Biol Chem. 2010 Feb 12;285(7):4909-19. doi: 10.1074/jbc.M109.042341. Epub 2009 , Dec 4. PMID:19965871 doi:10.1074/jbc.M109.042341
- ↑ Gilmore-Hebert M, Ramabhadran R, Stern DF. Interactions of ErbB4 and Kap1 connect the growth factor and DNA damage response pathways. Mol Cancer Res. 2010 Oct;8(10):1388-98. doi: 10.1158/1541-7786.MCR-10-0042. Epub , 2010 Sep 21. PMID:20858735 doi:10.1158/1541-7786.MCR-10-0042
- ↑ Fu X, Yucer N, Liu S, Li M, Yi P, Mu JJ, Yang T, Chu J, Jung SY, O'Malley BW, Gu W, Qin J, Wang Y. RFWD3-Mdm2 ubiquitin ligase complex positively regulates p53 stability in response to DNA damage. Proc Natl Acad Sci U S A. 2010 Mar 9;107(10):4579-84. doi:, 10.1073/pnas.0912094107. Epub 2010 Feb 19. PMID:20173098 doi:10.1073/pnas.0912094107
- ↑ Shin JS, Ha JH, Lee DH, Ryu KS, Bae KH, Park BC, Park SG, Yi GS, Chi SW. Structural convergence of unstructured p53 family transactivation domains in MDM2 recognition. Cell Cycle. 2015;14(4):533-43. doi: 10.1080/15384101.2014.998056. PMID:25591003 doi:http://dx.doi.org/10.1080/15384101.2014.998056
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