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From Proteopedia
Crystal structure of human MDM2 in complex with a trifluoromethylated D-peptide inhibitor
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 PubMedThe oncoprotein MDM2 negatively regulates the activity and stability of the p53 tumor suppressor and is an important molecular target for anticancer therapy. Aided by mirror image phage display and native chemical ligation, we have previously discovered several proteolysis-resistant duodecimal d-peptide antagonists of MDM2, termed (D)PMI-alpha, beta, gamma. The prototypic d-peptide inhibitor (D)PMI-alpha binds ((25-109))MDM2 at an affinity of 220 nM and kills tumor cells in vitro and inhibits tumor growth in vivo by reactivating the p53 pathway. Herein, we report the design of a superactive d-peptide antagonist of MDM2, termed (D)PMI-delta, of which the binding affinity for ((25-109))MDM2 has been improved over (D)PMI-alpha by 3 orders of magnitude (K(d) = 220 pM). X-ray crystallographic studies validate (D)PMI-delta as an exceedingly potent inhibitor of the p53-MDM2 interaction, promising to be a highly attractive lead drug candidate for anticancer therapeutic development. An Ultrahigh Affinity d-Peptide Antagonist Of MDM2.,Zhan C, Zhao L, Wei X, Wu X, Chen X, Yuan W, Lu WY, Pazgier M, Lu W J Med Chem. 2012 Jun 22. PMID:22694121[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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