Biological processes at the level of enzymes, receptors, ion channels, etc. are regulated via protein phosphorylation, catalysed by protein kinase enzymes. 518 different protein kinase enzymes have been described in the human genome, each with its own function. As key regulators of cell function, particularly in the context of abnormal activity in cancer cells, protein kinases have been the most studied targets in current drug research. More recently, several other areas for exploring these as drug targets have opened up, for example in rheumatoid arthritis and other inflammatory diseases and neurological disease.
The protein kinase, DYRK1A (Dual-specificity tyrosine phosphorylation-regulated kinase 1A), has not been as well studied but has been found to be a common factor across multiple diseases and to profoundly affect pathology in DS. The DYRK1A gene is located in the DSCR and DYRK1A has been identified as having a central function during early development, regulating cellular processes related to proliferation and differentiation of neural progenitor and other cells.