HIPK1

HIPK1, also referred to as DYRK6, is a nuclear kinase of the HIPK branch of the DYRK family. Its domain organization explains both its name and its function: the catalytic domain is followed by a homeodomain-interacting region that tethers it to homeodomain transcription factors, plus a CtBP-binding domain that recruits the transcriptional corepressor CtBP. Through these interactions HIPK1 modulates transcription-factor activity, Wnt-type signaling, and apoptosis. Expression is highest in testis and detectable across a range of somatic tissues. HIPK1 is less well characterized than HIPK2 but shares its activation-loop tyrosine autophosphorylation mechanism. The recombinant kinase supports studies of transcriptional repression and kinase-partner interactions.