3jzs
From Proteopedia
Human MDM2 liganded with a 12mer peptide inhibitor (pDIQ)
Structural highlights
DiseaseMDM2_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. FunctionMDM2_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] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMDM2 and MDMX function as key regulators of p53 by binding to its N terminus, inhibiting its transcriptional activity, and promoting degradation. MDM2 and MDMX overexpression or hyperactivation directly contributes to the loss of p53 function during the development of nearly 50% of human cancers. Recent studies showed that disrupting p53-MDM2 and p53-MDMX interactions can lead to robust activation of p53 but also revealed a need to develop novel dual specific or MDMX-specific inhibitors. Using phage display we identified a 12-residue peptide (pDI) with inhibitory activity against MDM2 and MDMX. The co-crystal structures of the pDI and a single mutant derivative (pDI6W) liganded with the N-terminal domains of human MDMX and MDM2 served as the basis for the design of 11 distinct pDI-derivative peptides that were tested for inhibitory potential. The best derivative (termed pDIQ) contained four amino acid substitutions and exhibited a 5-fold increase in potency over the parent peptide against both MDM2 (IC(50) = 8 nm) and MDMX (IC(50) = 110 nm). Further structural studies revealed key molecular features enabling the high affinity binding of the pDIQ to these proteins. These include large conformational changes of the pDIQ to reach into a hydrophobic site unique to MDMX. The findings suggest new strategies toward the rational design of small molecule inhibitors efficiently targeting MDMX. Structure-based design of high affinity peptides inhibiting the interaction of p53 with MDM2 and MDMX.,Phan J, Li Z, Kasprzak A, Li B, Sebti S, Guida W, Schonbrunn E, Chen J J Biol Chem. 2010 Jan 15;285(3):2174-83. Epub 2009 Nov 12. PMID:19910468[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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