5oai
Structure of MDM2 with low molecular weight inhibitorStructure of MDM2 with low molecular weight inhibitor
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] Publication Abstract from PubMedThe p53 protein is engaged in the repair of DNA mutations and elimination of heavily damaged cells, providing anti-cancer protection. Dysregulation of p53 activity is a crucial step in carcinogenesis. This dysregulation is often caused by the overexpression of negative regulators of p53, among which MDM2 is the most prominent one. Antagonizing MDM2 with small molecules restores the activity of p53 in p53 wild-type (p53(wt) ) cells and thus provides positive outcomes in the treatment of p53(wt) cancers. Previously, we have reported the discovery of a panel of fluoro-substituted indole-based antagonists of MDM2. Here, we demonstrate the biological activity and stereoselectivity of the most active compound from this series. Both enantiomers of the esterified form of the compound, as well as its corresponding carboxylic acids, were found active in fluorescence polarization (FP) assay, nuclear magnetic resonance (NMR) and microscale thermophoresis (MST) assay, with Ki and KD values around 1 muM. From these four compounds, the esterified enantiomer (R)-5a was active in cells, which was evidenced by the increase of p53 levels, the induced expression of p53-target genes (CDKN1A and MDM2), the selective induction of cell cycle arrest and selective growth inhibition of p53(wt) U-2 OS and SJSA-1 compared to p53(del) SAOS-2 cells. The analysis of the crystal structure of human MDM2 in complex with the compound (R)-6a (carboxylic acid of the active (R)-5a compound) revealed the classical three-finger binding mode. Altogether, our data demonstrate the activity of the compound and provide the structural basis for further structure optimization. This article is protected by copyright. All rights reserved. A fluorinated indole-based MDM2 antagonist selectively inhibits the growth of p53(wt) osteosarcoma cells.,Skalniak L, Twarda-Clapa A, Neochoritis CG, Surmiak E, Machula M, Wisniewska A, Labuzek B, Ali AM, Krzanik S, Dubin G, Groves M, Domling A, Holak TA FEBS J. 2019 Feb 4. doi: 10.1111/febs.14774. PMID:30715803[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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