HIPK3

HIPK3, sometimes called PKY, belongs to the HIPK branch of the DYRK family and is expressed broadly across tissues. It contains the catalytic domain, a homeodomain-interacting region, and a CtBP-binding domain, and it concentrates in the nucleus together with speckle-like structures. HIPK3 phosphorylates p53 and contributes to apoptosis following DNA damage, and it modulates the activity of homeodomain and other transcription factors through direct binding. Compared with HIPK2, it has been less intensively studied, and isoform- and cell-type-specific substrates are still being mapped. Recombinant HIPK3 is used for transcriptional-coregulator studies, DNA-damage signaling assays, and HIPK-family inhibitor profiling.