| 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
As key negative regulator of the p53 tumour suppressor, Mdm2 is an attractive therapeutic target. Small molecules such as Nutlin have been developed to antagonise Mdm2, resulting in p53-dependent death of tumour cells. We have recently described a mutation in Mdm2 (M62A), which precludes binding of Nutlin, but not p53. This Nutlin-resistant variant is not, however, refractory to binding and inhibition by stapled peptide antagonists targeting the same region of Mdm2. A detailed understanding of how stapled peptides are recalcitrant to Mdm2 mutations conferring Nutlin-resistance will aid in the further development of potent Mdm2 antagonists. Here, we report the 2.00 A crystal structure of a stapled peptide antagonist bound to Nutlin resistant Mdm2. The stapled peptide relies on an extended network of interactions along the hydrophobic binding cleft of Mdm2 for high affinity binding. Additionally, as seen in other stapled peptide structures, the hydrocarbon staple itself contributes to binding through favourable interactions with Mdm2. The structure highlights the intrinsic plasticity present in both Mdm2 and the hydrocarbon staple moiety, and can be used to guide future iterations of both small molecules and stapled peptides for improved antagonists of Mdm2.
Structure of a stapled Peptide antagonist bound to nutlin-resistant mdm2.,Chee SM, Wongsantichon J, Soo Tng Q, Robinson R, Joseph TL, Verma C, Lane DP, Brown CJ, Ghadessy FJ PLoS One. 2014 Aug 12;9(8):e104914. doi: 10.1371/journal.pone.0104914., eCollection 2014. PMID:25115702[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
- ↑ Chee SM, Wongsantichon J, Soo Tng Q, Robinson R, Joseph TL, Verma C, Lane DP, Brown CJ, Ghadessy FJ. Structure of a stapled Peptide antagonist bound to nutlin-resistant mdm2. PLoS One. 2014 Aug 12;9(8):e104914. doi: 10.1371/journal.pone.0104914., eCollection 2014. PMID:25115702 doi:http://dx.doi.org/10.1371/journal.pone.0104914
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