HIPK2 catalytic activity and subcellular localization are regulated by activation-loop Y354 autophosphorylation

► HIPK2 is catalytically activated by activation-loop Y354 autophosphorylation. ► Inhibition of HIPK2-Y354 phosphorylation results in out-of-target Y kinase activity. ► Out-of-target Y kinase activity delocalizes HIPK2 into cytoplasmic aggresomes. ► HIPK2 cytoplasmic aggresomes are reminiscent of similar observations in human cancers.