Proteome-wide analysis of phospho-regulated PDZ domain interactions

Research output: Contribution to journalArticlepeer-review


  • Gustav N Sundell
  • Muhammad Ali
  • Piangfan Naksukpaiboon
  • Julien Orts
  • Peter Güntert
  • Celestine N Chi
  • Ylva Ivarsson

Colleges, School and Institutes

External organisations

  • University of Uppsala
  • Laboratory of Physical Chemistry, ETH Zürich, Zürich, Switzerland.
  • Institute of Biophysical Chemistry, Goethe University, Frankfurt am Main, Germany.
  • Institute of Cancer and Genomic Science, University of Birmingham, UK.


A key function of reversible protein phosphorylation is to regulate protein-protein interactions, many of which involve short linear motifs (3-12 amino acids). Motif-based interactions are difficult to capture because of their often low-to-moderate affinities. Here, we describe phosphomimetic proteomic peptide-phage display, a powerful method for simultaneously finding motif-based interaction and pinpointing phosphorylation switches. We computationally designed an oligonucleotide library encoding human C-terminal peptides containing known or predicted Ser/Thr phosphosites and phosphomimetic variants thereof. We incorporated these oligonucleotides into a phage library and screened the PDZ (PSD-95/Dlg/ZO-1) domains of Scribble and DLG1 for interactions potentially enabled or disabled by ligand phosphorylation. We identified known and novel binders and characterized selected interactions through microscale thermophoresis, isothermal titration calorimetry, and NMR We uncover site-specific phospho-regulation of PDZ domain interactions, provide a structural framework for how PDZ domains accomplish phosphopeptide binding, and discuss ligand phosphorylation as a switching mechanism of PDZ domain interactions. The approach is readily scalable and can be used to explore the potential phospho-regulation of motif-based interactions on a large scale.


Original languageEnglish
Pages (from-to)e8129
JournalMolecular Systems Biology
Issue number8
Publication statusPublished - 20 Aug 2018