A systems wide mass spectrometric based linear motif screen to identify dominant in-vivo interacting proteins for the ubiquitin ligase MDM2

Judith Nicholson, Alex Scherl, Luke Way, Elizabeth A. Blackburn, Malcolm D. Walkinshaw, Kathryn L. Ball, Ted R. Hupp*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Linear motifs mediate protein-protein interactions (PPI) that allow expansion of a target protein interactome at a systems level. This study uses a proteomics approach and linear motif sub-stratifications to expand on PPIs of MDM2. MDM2 is a multi-functional protein with over one hundred known binding partners not stratified by hierarchy or function. A new linear motif based on a MDM2 interaction consensus is used to select novel MDM2 interactors based on Nutlin-3 responsiveness in a cell-based proteomics screen. MDM2 binds a subset of peptide motifs corresponding to real proteins with a range of allosteric responses to MDM2 ligands. We validate cyclophilin B as a novel protein with a consensus MDM2 binding motif that is stabilised by Nutlin-3 in vivo, thus identifying one of the few known interactors of MDM2 that is stabilised by Nutlin-3. These data invoke two modes of peptide binding at the MDM2 N-terminus that rely on a consensus core motif to control the equilibrium between MDM2 binding proteins. This approach stratifies MDM2 interacting proteins based on the linear motif feature and provides a new biomarker assay to define clinically relevant Nutlin-3 responsive MDM2 interactors. (C) 2014 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)1243-1257
Number of pages15
JournalCellular Signalling
Volume26
Issue number6
Early online date28 Feb 2014
DOIs
Publication statusPublished - Jun 2014

Keywords

  • MDM2
  • Interactome
  • Linear motifs
  • CypB
  • Proteomics
  • P53 TUMOR-SUPPRESSOR
  • N-TERMINAL DOMAIN
  • STRUCTURAL BASIS
  • PROTEOMICS
  • BINDING
  • PEPTIDE
  • PATHWAY
  • E3
  • APOPTOSIS
  • NETWORKS

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