DYRK1A

DYRK1A lies in the Down syndrome critical region of chromosome 21, and its dosage is directly pathogenic: trisomy contributes to the cognitive deficits of Down syndrome, while heterozygous loss of function causes an autism-intellectual disability syndrome with microcephaly. The kinase autophosphorylates a tyrosine in its activation loop during maturation and then functions as a constitutive serine/threonine kinase acting on substrates that include tau, RCAN1, amphiphysin 1, synaptojanin 1, and cyclin D1. It is enriched in brain, localizes to nucleus and cytoplasm, and regulates neuronal differentiation, dendritic spine formation, and cell-cycle exit. Recombinant DYRK1A supports neurodevelopmental research and inhibitor discovery.