Selectivity profiling of inhibitor treated human cells via full proteome profiling

Three selective hit compounds from an arrayed kinome abundance screen (98 kinases vs 1570 kinase inhibitors) were subjected to full proteome profiling by TMTpro 18-plex to assess their degradation selectivity in K562 cells. Src inhibitor 3 showed the most significant downregulation of the target kinase LYN. TAK285 did not significantly affect any kinase. Finally, CSK and RIPK2 (drug screen targets) were identified as the only two kinase targets downregulated by RIPK-IN-4. The compounds were further assessed for their detailed mode of action as reported with orthogonal assays such as FACS-based CRISPR/Cas9 screens and BioID.