E3 ubiquitin-protein ligase which is a component of the N-end rule pathway. Recognizes and binds to proteins bearing specific N-terminal residues that are destabilizing according to the N-end rule, leading to their ubiquitination and subsequent degradation. Involved in maturation and/or transcriptional regulation of mRNA by activating CDK9 by polyubiquitination. May play a role in control of cell cycle progression. May have tumor suppressor function. Regulates DNA topoisomerase II binding protein (TopBP1) in the DNA damage response. Plays an essential role in extraembryonic development. Ubiquitinates acetylated PCK1. Binds TOPBP1. Associates with CDK9 and TFIIS/TCEA1 and forms a transcription regulatory complex made of CDK9, RNAP II, UBR5 and TFIIS/TCEA1 that can stimulates target gene transcription (e.g. gamma fibrinogen/FGG) by recruiting their promoters. Associates with the E3 ligase complex containing DYRK2, EDD/UBR5, DDB1 and VPRBP proteins (EDVP complex). Interacts directly with DYRK2. Widely expressed. Most abundant in testis and expressed at high levels in brain, pituitary and kidney. Note: This description may include information from UniProtKB.
Molecular Function: ubiquitin binding; protein binding; zinc ion binding; RNA binding; ubiquitin-protein ligase activity
Biological Process: ubiquitin-dependent protein catabolic process; cell proliferation; progesterone receptor signaling pathway; protein polyubiquitination; positive regulation of protein import into nucleus, translocation; protein ubiquitination during ubiquitin-dependent protein catabolic process; DNA repair; response to DNA damage stimulus
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.