UniProt functional annotation for P30291

UniProt code: P30291.

Organism: Homo sapiens (Human).
Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.
 
Function: Acts as a negative regulator of entry into mitosis (G2 to M transition) by protecting the nucleus from cytoplasmically activated cyclin B1-complexed CDK1 before the onset of mitosis by mediating phosphorylation of CDK1 on 'Tyr-15'. Specifically phosphorylates and inactivates cyclin B1-complexed CDK1 reaching a maximum during G2 phase and a minimum as cells enter M phase. Phosphorylation of cyclin B1-CDK1 occurs exclusively on 'Tyr-15' and phosphorylation of monomeric CDK1 does not occur. Its activity increases during S and G2 phases and decreases at M phase when it is hyperphosphorylated. A correlated decrease in protein level occurs at M/G1 phase, probably due to its degradation.
 
Catalytic activity: Reaction=ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl- [protein]; Xref=Rhea:RHEA:10596, Rhea:RHEA-COMP:10136, Rhea:RHEA- COMP:10137, ChEBI:CHEBI:15378, ChEBI:CHEBI:30616, ChEBI:CHEBI:46858, ChEBI:CHEBI:82620, ChEBI:CHEBI:456216; EC=2.7.10.2; Evidence={ECO:0000255|PROSITE-ProRule:PRU10027};
Cofactor: Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Note=Binds 2 magnesium ions per subunit.;
Activity regulation: Synthesis is increased during S and G2 phases, presumably by an increase in transcription; activity is decreased by phosphorylation during m phase. Protein levels fall in M phase as a result of decreased synthesis combined with degradation. Activity seems to be negatively regulated by phosphorylation upon entry into mitosis, although N-terminal phosphorylation might also regulate the protein stability via protection from proteolysis or might regulate the subcellular location.
Subcellular location: Nucleus.
Ptm: Phosphorylated during M and G1 phases. Also autophosphorylated. Phosphorylation at Ser-642 by BRSK1 and BRSK2 in post-mitotic neurons, leads to down-regulate WEE1 activity in polarized neurons. Phosphorylated at Ser-53 and Ser-123 by PLK1 and CDK1, respectively, generating an signal for degradation that can be recognized by the SCF(BTRC) complex, leading to its ubiquitination and degradation at the onset of G2/M phase. {ECO:0000269|PubMed:15070733, ECO:0000269|PubMed:15150265, ECO:0000269|PubMed:20026642, ECO:0000269|PubMed:22692537}.
Ptm: Dephosphorylated at Thr-239 by CTDP1 (PubMed:22692537). Dephosphorylated at Ser-53 and Ser-123 by the serine/threonine-protein phosphatase 2A preventing its ubiquitin-mediated degradation (PubMed:33108758). {ECO:0000269|PubMed:22692537, ECO:0000269|PubMed:33108758}.
Ptm: Ubiquitinated and degraded at the onset of G2/M phase. {ECO:0000269|PubMed:15070733}.
Similarity: Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. WEE1 subfamily. {ECO:0000255|PROSITE-ProRule:PRU00159}.

Annotations taken from UniProtKB at the EBI.