Casein kinase 2, alpha 1

See also: Casein kinase 2

Casein kinase II subunit alpha 1 (CK2α) is an enzyme that in humans is encoded by the CSNK2A1 gene, located on chromosome 20.^[5][6]

CSNK2A1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1JWH, 1NA7, 1PJK, 2PVR, 2ZJW, 3AMY, 3AT2, 3AT3, 3AT4, 3AXW, 3BQC, 3C13, 3FWQ, 3H30, 3JUH, 3MB6, 3MB7, 3NGA, 3NSZ, 3OWJ, 3OWK, 3OWL, 3PE1, 3PE2, 3PE4, 3Q04, 3Q9W, 3Q9X, 3Q9Y, 3Q9Z, 3QA0, 3R0T, 3RPS, 3TAX, 3U4U, 3U87, 3U9C, 3W8L, 3WAR, 3WIK, 3WIL, 3WOW, 4DGL, 4FBX, 4GRB, 4GUB, 4GYW, 4GYY, 4GZ3, 4IB5, 4KWP, 4MD7, 4MD8, 4MD9, 4NH1, 4RLL, 4UB7, 4UBA, 5CQU, 5CQW, 5H8G, 5H8B, 5H8E, 5CLP, 5CSH, 5CVH, 5CS6, 5CU6, 5B0X
Identifiers
Aliases	CSNK2A1, Csnk2a1, Csnk2a1-rs4, CK2A1, CKII, CSNK2A3, casein kinase 2 alpha 1, OCNDS, Cka1, Cka2
External IDs	OMIM: 115440; MGI: 88543; HomoloGene: 90874; GeneCards: CSNK2A1; OMA:CSNK2A1 - orthologs
Gene location (Human) Chr. Chromosome 20 (human)[1] Band 20p13 Start 472,498 bp[1] End 543,835 bp[1]
Gene location (Mouse) Chr. Chromosome 2 (mouse)[2] Band 2|2 G3 Start 152,068,759 bp[2] End 152,123,772 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in ganglionic eminence ventricular zone epithelium of colon gingival epithelium Achilles tendon islet of Langerhans rectum stromal cell of endometrium gastrocnemius muscle amniotic fluid Top expressed in genital tubercle tail of embryo lumbar spinal ganglion ventricular zone zygote epiblast blastocyst muscle of thigh ganglionic eminence extensor digitorum longus muscle More reference expression data BioGPS More reference expression data
Gene ontology Molecular function transferase activity nucleotide binding Hsp90 protein binding protein kinase activity protein N-terminus binding protein serine/threonine kinase activity protein binding ATP binding kinase activity beta-catenin binding protein phosphatase regulator activity ribonucleoprotein complex binding identical protein binding Cellular component NuRD complex cytosol Sin3 complex PcG protein complex nucleus nucleoplasm protein kinase CK2 complex chromatin cytoplasm plasma membrane Biological process chaperone-mediated protein folding negative regulation of cysteine-type endopeptidase activity involved in apoptotic process regulation of transcription, DNA-templated positive regulation of protein catabolic process phosphorylation rhythmic process Wnt signaling pathway transcription, DNA-templated positive regulation of Wnt signaling pathway protein phosphorylation positive regulation of cell growth positive regulation of cell population proliferation cell cycle signal transduction apoptotic process regulation of signal transduction by p53 class mediator protein folding phosphatidylcholine biosynthetic process macroautophagy peptidyl-threonine phosphorylation cerebral cortex development response to testosterone protein autophosphorylation liver regeneration regulation of protein localization to plasma membrane regulation of chromosome separation peptidyl-serine phosphorylation negative regulation of ubiquitin-dependent protein catabolic process negative regulation of apoptotic signaling pathway Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 1457 12995 Ensembl ENSG00000101266 ENSMUSG00000074698 UniProt P68400 Q5U5J2 Q60737 RefSeq (mRNA) NM_001895 NM_177559 NM_177560 NM_001362770 NM_001362771 NM_007788 RefSeq (protein) NP_001886 NP_808227 NP_808228 NP_001349699 NP_001349700 NP_031814 Location (UCSC) Chr 20: 0.47 – 0.54 Mb Chr 2: 152.07 – 152.12 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

CK2α is the alpha catalytic subunit of Casein kinase II (CK2). CK2 is a serine/threonine protein kinase that phosphorylates acidic proteins such as casein. The kinase exists in monomeric form and as a tetramer and is composed of two α or α' (alpha prime) subunits and two β subunits; the CK2 holoenzyme has α2β2 stoichiometry.^[7][8] The alpha subunits contain the catalytic activity while the beta subunits undergo autophosphorylation. The protein encoded by this gene represents the alpha subunit. Three transcript variants encoding two different proteins have been found for this gene.^[9] CK2α' paralog is encoded by the CSNK2A2 gene; it differs in the length and sequence of the C-terminus of the protein.^[10]

Protein Kinase Phosphoryl transfer

Gene Location

The CSNK2A1 gene is located on chromosome 20 in humans. In 2025, analyses revealed that CSNK2A1 has 14 exons (rather than 13 exons as previously reported).^[11] Protein translation begins 110 nucleotides into exon 3; exons 1 and 2 are entirely untranslated.^[12] CSNK2A1 mRNA contains 12,984 nucleotides (coding sequence is 1,176 nucleotides), spanning approximately 71 kb.^[11] CSNK2A1 contains 391 amino acids.^[13]

Function

CK2α has been implicated in many diseases including cancer, autoimmune disorders, COVID-19, psychiatric disorders, ophthalmic diseases, obesity, diabetes, cardiovascular disorders, neurological disorders, and most recently, Okur-Chung Neurodevelopmental Syndrome (OCNDS).^[14] It has roles in cell cycle progression, viral infection, apoptosis, transcription, and regulating circadian rhythms.^[15][16]

CSNK2A1 contains highly conserved functional domains, including a glycine-rich loop, which is a critical structure common to kinases that has roles in substrate recognition, enzyme catalysis, and nucleotide binding. While both alpha isoforms (α, α') are present in major brain regions, there is a predominance of CK2α over CK2α' in the mammalian brain at an approximate ratio of CK2α:CK2α' as 8:1.^[17]

Clinical Significance

Mutations in CSNK2A1 are causative for Okur-Chung Neurodevelopmental Syndrome (OCNDS).^[18] There are "hot spots" where mutations are more likely to occur, with ~33% of individuals with OCNDS harboring the same genetic change: p. Lys198R^[19]

Interactions

More than one-third of CK2 protein substrates are implicated in gene expression and protein synthesis as either transcription factors, translational elements, or effectors of DNA/RNA structure.^[20] Casein kinase 2, alpha 1 has been shown to interact with:

• APC,^[21]
• ATF1,^[22]
• ATF2,^[22]
• C-Fos,^[22]
• C-jun,^[22]
• CDC25B,^[23]
• CHEK1,^[24][25]
• CREBBP,^[22]
• CSNK2B,^{[26][27][28][29][30]}
• DDIT3,^[31]
• FGF1,^[32]
• FGF2,^[32]
• HNRPA2B1^[33]
• MAPK14,^[34]
• PIN1,^[35]
• PLEKHO1,^[26]
• PTEN,^[36]
• RELA,^[37]
• TAF1,^[38] and
• UBTF.^[39]