UniProt functional annotation for P68400

UniProt code: P68400.

Organism: Homo sapiens (Human).
Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.
 
Function: 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 (PubMed:11239457, PubMed:11704824, PubMed:16193064, PubMed:19188443, PubMed:20625391, PubMed:22406621, PubMed:24962073). Regulates numerous cellular processes, such as cell cycle progression, apoptosis and transcription, as well as viral infection (PubMed:12631575, PubMed:19387552, PubMed:19387551). May act as a regulatory node which integrates and coordinates numerous signals leading to an appropriate cellular response (PubMed:12631575, PubMed:19387552, PubMed:19387551). During mitosis, 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 (PubMed:11704824, PubMed:19188443). Also required for p53/TP53-mediated apoptosis, phosphorylating 'Ser-392' of p53/TP53 following UV irradiation. Can also negatively regulate apoptosis (PubMed:11239457). Phosphorylates the caspases CASP9 and CASP2 and the apoptotic regulator NOL3 (PubMed:16193064). Phosphorylation protects CASP9 from cleavage and activation by CASP8, and inhibits the dimerization of CASP2 and activation of CASP8 (PubMed:16193064). Regulates transcription by direct phosphorylation of RNA polymerases I, II, III and IV. Also phosphorylates and regulates numerous transcription factors including NF-kappa-B, STAT1, CREB1, IRF1, IRF2, ATF1, ATF4, SRF, MAX, JUN, FOS, MYC and MYB (PubMed:19387550, PubMed:12631575, PubMed:19387552, PubMed:19387551, PubMed:23123191). Phosphorylates Hsp90 and its co-chaperones FKBP4 and CDC37, which is essential for chaperone function (PubMed:19387550). Mediates sequential phosphorylation of FNIP1, promoting its gradual interaction with Hsp90, leading to activate both kinase and non-kinase client proteins of Hsp90 (PubMed:30699359). Regulates Wnt signaling by phosphorylating CTNNB1 and the transcription factor LEF1 (PubMed:19387549). Acts as an ectokinase that phosphorylates several extracellular proteins (PubMed:19387550, PubMed:12631575, PubMed:19387552, PubMed:19387551). During viral infection, phosphorylates various proteins involved in the viral life cycles of EBV, HSV, HBV, HCV, HIV, CMV and HPV (PubMed:19387550, PubMed:12631575, PubMed:19387552, PubMed:19387551). Phosphorylates PML at 'Ser-565' and primes it for ubiquitin-mediated degradation (PubMed:20625391, PubMed:22406621). Plays an important role in the circadian clock function by phosphorylating ARNTL/BMAL1 at 'Ser- 90' which is pivotal for its interaction with CLOCK and which controls CLOCK nuclear entry (By similarity). Phosphorylates CCAR2 at 'Thr-454' in gastric carcinoma tissue (PubMed:24962073). {ECO:0000250|UniProtKB:P19139, ECO:0000269|PubMed:11239457, ECO:0000269|PubMed:11704824, ECO:0000269|PubMed:16193064, ECO:0000269|PubMed:19188443, ECO:0000269|PubMed:20625391, ECO:0000269|PubMed:22406621, ECO:0000269|PubMed:23123191, ECO:0000269|PubMed:24962073, ECO:0000269|PubMed:30699359, ECO:0000303|PubMed:12631575, ECO:0000303|PubMed:19387549, ECO:0000303|PubMed:19387550, ECO:0000303|PubMed:19387551, ECO:0000303|PubMed:19387552}.
 
Catalytic activity: Reaction=ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl- [protein]; Xref=Rhea:RHEA:17989, Rhea:RHEA-COMP:9863, Rhea:RHEA- COMP:11604, ChEBI:CHEBI:15378, ChEBI:CHEBI:29999, ChEBI:CHEBI:30616, ChEBI:CHEBI:83421, ChEBI:CHEBI:456216; EC=2.7.11.1; Evidence={ECO:0000269|PubMed:20625391, ECO:0000269|PubMed:23123191, ECO:0000269|PubMed:30699359}; PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:17990; Evidence={ECO:0000269|PubMed:23123191, ECO:0000269|PubMed:30699359};
Catalytic activity: Reaction=ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L- threonyl-[protein]; Xref=Rhea:RHEA:46608, Rhea:RHEA-COMP:11060, Rhea:RHEA-COMP:11605, ChEBI:CHEBI:15378, ChEBI:CHEBI:30013, ChEBI:CHEBI:30616, ChEBI:CHEBI:61977, ChEBI:CHEBI:456216; EC=2.7.11.1; Evidence={ECO:0000269|PubMed:20625391};
Activity regulation: Constitutively active protein kinase whose activity is not directly affected by phosphorylation. Seems to be regulated by level of expression and localization.
Subunit: Heterotetramer composed of two catalytic subunits (alpha chain and/or alpha' chain) and two regulatory subunits (beta chains). The tetramer can exist as a combination of 2 alpha/2 beta, 2 alpha'/2 beta or 1 alpha/1 alpha'/2 beta subunits. Also part of a CK2-SPT16-SSRP1 complex composed of SSRP1, SUPT16H, CSNK2A1, CSNK2A2 and CSNK2B, which forms following UV irradiation. Interacts with RNPS1. Interacts with SNAI1. Interacts with PML (isoform PML-12). Interacts with CCAR2. {ECO:0000269|PubMed:11092945, ECO:0000269|PubMed:11239457, ECO:0000269|PubMed:11574463, ECO:0000269|PubMed:12393879, ECO:0000269|PubMed:15684395, ECO:0000269|PubMed:19923321, ECO:0000269|PubMed:20625391, ECO:0000269|PubMed:22406621, ECO:0000269|PubMed:24962073}.
Subcellular location: Nucleus {ECO:0000269|PubMed:23123191, ECO:0000269|PubMed:24962073}.
Tissue specificity: Expressed in gastric carcinoma tissue and the expression gradually increases with the progression of the carcinoma (at protein level). {ECO:0000269|PubMed:24962073}.
Ptm: Phosphorylated at Thr-344, Thr-360, Ser-362 and Ser-370 by CDK1 in prophase and metaphase and dephosphorylated during anaphase. Phosphorylation does not directly affect casein kinase 2 activity, but may contribute to its regulation by forming binding sites for interacting proteins and/or targeting it to different compartments. {ECO:0000269|PubMed:7592773}.
Disease: Okur-Chung neurodevelopmental syndrome (OCNDS) [MIM:617062]: An autosomal dominant neurodevelopmental disorder characterized by developmental delay, intellectual disability, behavioral problems, hypotonia, speech problems, microcephaly, pachygyria and variable dysmorphic features. {ECO:0000269|PubMed:27048600}. Note=The disease is caused by variants affecting the gene represented in this entry.
Miscellaneous: Can use both ATP and GTP as phosphoryl donors. Phosphorylation by casein kinase 2 has been estimated to represent up to one quarter of the eukaryotic phosphoproteome. Casein kinase 2 has been found to be increased at protein level and up-regulated at the level of enzyme activity in the majority of cancers. However, elevated levels of casein kinase 2 are present in certain normal organs such as brain and testes.
Similarity: Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. CK2 subfamily. {ECO:0000255|PROSITE-ProRule:PRU00159}.

Annotations taken from UniProtKB at the EBI.