Casein kinase II subunit alpha (CSNK2A1) is a catalytic subunit of a constitutively active serine/threonine-protein kinase complex that phosphorylates a large number of substrates containing acidic residues C-terminal to the phosphorylated serine or threonine. CSNK2A1 regulates numerous cellular processes, such as cell cycle progression, apoptosis and transcription, as well as viral infection. During mitosis, CSNK2A1 functions as a component of the p53/TP53-dependent spindle assembly checkpoint (SAC) that maintains cyclin-B-CDK1 activity and G2 arrest in response to spindle damage.
