Illuminating DYRK1A Substrates Through a Multi‐omic Drug Based Approach

Abstract

Protein kinases comprise only ~2.5% of human protein coding genes yet are responsible for the regulation of nearly every cellular process through their catalytic activity. The kinome thus represents one of the most druggable classes of regulatory proteins for human disease. However, despite major advances in protein identification through mass‐spectrometry based techniques, it remains difficult to uncover substrate profiles for individual kinases using pharmacological manipulation. Undesirable off‐target inhibition and diverse secondary events muddle the phosphorylation landscape that can be detected using phosphoproteomic methods. Further, phosphorylation events and target engagement are often cell type specific confounding our ability to discern contributions of off‐target kinases. Using the protein kinase DYRK1A and inhibitor harmine as a model, we utilize orthogonal mass spectrometry‐based approaches to distinguish kinase‐substrates. Thermal proteome profiling revealed that harmine differentially stabilizes proteins in a cell type and dose dependent manner. Drug target stabilization in combination with substrate motif analysis were used to elucidate high‐confidence DYRK1A substrates from a SILAC‐based harmine phosphoproteome. The substrates revealed in this study will be crucial to understanding DYRK1A function and contribution to human health.Support or Funding InformationDARPA cooperative agreement 13‐34‐RTA‐FP‐007 to W.M.OLinda Crnic Institute for Down syndrome‐ Grand Challenge GrantThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.