Protein kinase CK2 (Casein Kinase 2) is an ubiquitous, highly pleiotropic,
constitutive active and essential protein kinase, with both cytosolic and nuclear
localization in most mammalian cells. The holoenzyme is generally composed of two
catalytic (alpha and/or alpha') and two regulatory (beta) subunits, but the free
alpha/alpha' subunits are catalytically active by themselves and can be present in cells
under some circumstances. CK2 catalyzes the phosphorylation of more than 300
substrates characterized by multiple acidic residues surrounding the phosphor-acceptor
amino acid and, consequently, it plays a key role in several physiological and
pathological processes. It’s abnormally high constitutive activity is implicated in several
diseases and neoplasia, and a number of ATP competitive inhibitors of CK2 with
micromolar and nanomolar in vitro activity, display a pro-apoptotic effect also in cell.
Keywords: CK2, protein kinases, inhibitors, cancer, neurodegenerative diseases,
viral infections
