DYRKs (dual-specificity tyrosine-regulated kinases; dual-specificity tyrosine phosphorylation-regulated kinases) comprise a family of protein kinases within the CMGC group of the eukaryotic kinome. DYRKs contain five members in humans that are clustered into two classes based on their phylogenetic relationships: class I DYRKs, DYRK1A and DYRK1B and class II DYRKs, DYRK2, DYRK3, and DYRK4.
DYRK kinases are “dual specificity” kinases, as they can phosphorylate both tyrosine (Y) and serine/threonine (S/T) residues, although Y-phosphorylation is limited to their autophosphorylation activity. DYRK kinases phosphorylate a broad set of substrates that are involved in a wide range of cellular processes, and they are thought to fulfill essential biological functions both during development and in maintaining homeostasis during the adult life. Consequently, the aberrant regulation or expression of DYRK kinases has been associated with several human pathologies, including cancer.