A Split-Abl Kinase for Direct Activation in Cells

Cell Chem Biol. 2017 Oct 19;24(10):1250-1258.e4. doi: 10.1016/j.chembiol.2017.08.007. Epub 2017 Sep 14.


To dissect the cellular roles of individual kinases, it is useful to design tools for their selective activation. We describe the engineering of a split-cAbl kinase (sKin-Abl) that is rapidly activated in cells with rapamycin and allows temporal, dose, and compartmentalization control. Our design strategy involves an empirical screen in mammalian cells and identification of split site in the N lobe. This split site leads to complete loss of activity, which can be restored upon small-molecule-induced dimerization in cells. Remarkably, the split site is transportable to the related Src Tyr kinase and the distantly related Ser/Thr kinase, AKT, suggesting broader applications to kinases. To quantify the fold induction of phosphotyrosine (pTyr) modification, we employed quantitative proteomics, NeuCode SILAC. We identified a number of known Abl substrates, including autophosphorylation sites and novel pTyr targets, 432 pTyr sites in total. We believe that this split-kinase technology will be useful for direct activation of protein kinases in cells.

Keywords: ABL kinase; NeuCode; phosphoproteomics; protein kinase; selective kinase activation; split-protein engineering.

MeSH terms

  • Enzyme Activation / drug effects
  • HEK293 Cells
  • Humans
  • Phosphorylation
  • Phosphotyrosine / metabolism
  • Protein Engineering*
  • Proto-Oncogene Proteins c-abl / genetics
  • Proto-Oncogene Proteins c-abl / metabolism*
  • Sirolimus / pharmacology
  • src-Family Kinases / genetics


  • Phosphotyrosine
  • Proto-Oncogene Proteins c-abl
  • src-Family Kinases
  • Sirolimus