Casein kinase 2 (CK2) (CK2)

Casein kinase 2 (CK2) is a ubiquitous and constitutively active serine/threonine-protein kinase that typically functions as a heterotetrameric complex composed of two catalytic subunits (alpha and/or alpha-prime) and two regulatory beta subunits [UniProt]. It is a master regulator in the cell, phosphorylating over 300 substrates involved in signal transduction, cell cycle progression, and the suppression of apoptosis [PubMed: 29107105, NIH]. In many pathological conditions, particularly various malignancies, CK2 is frequently overexpressed, which drives tumor survival, proliferation, and resistance to therapy by stabilizing oncogenic proteins and inhibiting tumor suppressors like p53 [PubMed: 26239591, PubMed: 18466114]. Because of its central role in promoting cell survival and its involvement in multiple oncogenic pathways, CK2 has emerged as a significant therapeutic target. Small molecule inhibitors such as silmitasertib (CX-4945) are currently being evaluated in clinical trials for their ability to selectively block CK2 activity and induce apoptosis in cancer cells [ClinicalTrials.gov]. Beyond oncology, CK2 is also implicated in viral replication, inflammatory responses, and neurodegenerative conditions, making it a versatile target for drug development [PubMed: 30634458].

Other names

CSNK2Protein kinase CK2CKIICasein kinase IICSNK2A1CSNK2A2CSNK2B

ATP-competitive inhibition of the catalytic alpha and alpha-prime subunits; disruption of the interaction between catalytic and regulatory beta subunits to prevent holoenzyme formation.