UniProt functional annotation for Q5VTR2

UniProt code: Q5VTR2.

Organism: Homo sapiens (Human).
Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.
 
Function: Component of the RNF20/40 E3 ubiquitin-protein ligase complex that mediates monoubiquitination of 'Lys-120' of histone H2B (H2BK120ub1). H2BK120ub1 gives a specific tag for epigenetic transcriptional activation and is also prerequisite for histone H3 'Lys-4' and 'Lys-79' methylation (H3K4me and H3K79me, respectively). It thereby plays a central role inb histone code and gene regulation. The RNF20/40 complex forms a H2B ubiquitin ligase complex in cooperation with the E2 enzyme UBE2A or UBE2B; reports about the cooperation with UBE2E1/UBCH are contradictory. Required for transcriptional activation of Hox genes. Recruited to the MDM2 promoter, probably by being recruited by p53/TP53, and thereby acts as a transcriptional coactivator. Mediates the polyubiquitination of isoform 2 of PA2G4 in cancer cells leading to its proteasome-mediated degradation. {ECO:0000269|PubMed:16307923, ECO:0000269|PubMed:16337599, ECO:0000269|PubMed:19037095, ECO:0000269|PubMed:19410543}.
 
Catalytic activity: Reaction=S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L- cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine.; EC=2.3.2.27; Evidence={ECO:0000269|PubMed:16307923, ECO:0000269|PubMed:16337599, ECO:0000269|PubMed:19410543};
Pathway: Protein modification; protein ubiquitination.
Subunit: Component of the RNF20/40 complex (also known as BRE1 complex) probably composed of 2 copies of RNF20/BRE1A and 2 copies of RNF40/BRE1B. Interacts with UBE2E1/UBCH6. Interacts with p53/TP53 and WAC. Interacts with PAF1; the interaction mediates the association of the PAF1 and RNF20/40 complexes which is a prerequsite for recruitment of UBE2A/B. Interacts with isoform 1 and isoform 2 of PA2G4. {ECO:0000269|PubMed:16307923, ECO:0000269|PubMed:16337599, ECO:0000269|PubMed:19037095, ECO:0000269|PubMed:19410543, ECO:0000269|PubMed:21329877}.
Subcellular location: Nucleus {ECO:0000269|PubMed:19037095, ECO:0000305|PubMed:16337599}.
Tissue specificity: Expressed in the normal brain and also in malignant gliomas (at protein level). {ECO:0000269|PubMed:19037095}.
Similarity: Belongs to the BRE1 family. {ECO:0000305}.
Sequence caution: Sequence=AAH63115.1; Type=Miscellaneous discrepancy; Note=Contaminating sequence. Potential poly-A sequence.; Evidence={ECO:0000305}; Sequence=BAA91326.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305}; Sequence=BAA92057.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305}; Sequence=BAB14005.1; Type=Erroneous initiation; Note=Truncated N-terminus.; Evidence={ECO:0000305};

Annotations taken from UniProtKB at the EBI.