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Lookup NU author(s): Professor Matthias TrostORCiD
This is the authors' accepted manuscript of an article that has been published in its final definitive form by Nature Publishing Group, 2017.
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© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. The ubiquitin system regulates essential cellular processes in eukaryotes. Ubiquitin is ligated to substrate proteins as monomers or chains and the topology of ubiquitin modifications regulates substrate interactions with specific proteins. Thus ubiquitination directs a variety of substrate fates including proteasomal degradation. Deubiquitinase enzymes cleave ubiquitin from substrates and are implicated in disease; for example, ubiquitin-specific protease-7 (USP7) regulates stability of the p53 tumour suppressor and other proteins critical for tumour cell survival. However, developing selective deubiquitinase inhibitors has been challenging and no co-crystal structures have been solved with small-molecule inhibitors. Here, using nuclear magnetic resonance-based screening and structure-based design, we describe the development of selective USP7 inhibitors GNE-6640 and GNE-6776. These compounds induce tumour cell death and enhance cytotoxicity with chemotherapeutic agents and targeted compounds, including PIM kinase inhibitors. Structural studies reveal that GNE-6640 and GNE-6776 non-covalently target USP7 12 Å distant from the catalytic cysteine. The compounds attenuate ubiquitin binding and thus inhibit USP7 deubiquitinase activity. GNE-6640 and GNE-6776 interact with acidic residues that mediate hydrogen-bond interactions with the ubiquitin Lys48 side chain, suggesting that USP7 preferentially interacts with and cleaves ubiquitin moieties that have free Lys48 side chains. We investigated this idea by engineering di-ubiquitin chains containing differential proximal and distal isotopic labels and measuring USP7 binding by nuclear magnetic resonance. This preferential binding protracted the depolymerization kinetics of Lys48-linked ubiquitin chains relative to Lys63-linked chains. In summary, engineering compounds that inhibit USP7 activity by attenuating ubiquitin binding suggests opportunities for developing other deubiquitinase inhibitors and may be a strategy more broadly applicable to inhibiting proteins that require ubiquitin binding for full functional activity.
Author(s): Kategaya L, Di Lello P, Rouge L, Pastor R, Clark KR, Drummond J, Kleinheinz T, Lin E, Upton J-P, Prakash S, Heideker J, McCleland M, Ritorto MS, Alessi DR, Trost M, Bainbridge TW, Kwok MCM, Ma TP, Stiffler Z, Brasher B, Tang Y, Jaishankar P, Hearn BR, Renslo AR, Arkin MR, Cohen F, Yu K, Peale F, Gnad F, Chang MT, Klijn C, Blackwood E, Martin SE, Forrest WF, Ernst JA, Ndubaku C, Wang X, Beresini MH, Tsui V, Schwerdtfeger C, Blake RA, Murray J, Maurer T, Wertz IE
Publication type: Article
Publication status: Published
Print publication date: 26/10/2017
Online publication date: 18/10/2017
Acceptance date: 16/08/2017
Date deposited: 23/08/2018
ISSN (print): 0028-0836
ISSN (electronic): 1476-4687
Publisher: Nature Publishing Group
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