DYRK1 is a dual-specificity protein kinase that catalyzes its autophosphorylation on serine/threonine and tyrosine residues and is presumably involved in brain development.
Human fetal brain DYRK2 (GenBank Y13493) cDNAs encode 2 isoforms: a deduced 528-amino acid protein and a protein containing 73 additional amino acids at the N terminus. The DYRK2 proteins contain a canonical kinase domain located between a large N-terminal region and a short C-terminal extension, and features specific to DYRK-related kinases. DYRK2 shares 46% identity with DYRK1 in the catalytic domain, but lacks the striking sequence motifs identified in DYRK1.
The DYRK2 and DYRK3 proteins are related over their entire sequences except for the N-terminal region.
Northern blot analysis of rat tissues detected Dyrk2 expression in testis, only after the onset of spermatogenesis. Recombinant DYRK2 was found predominantly in the cytoplasm of transfected mammalian cells.