UBR2
Developmental stage
Expressed in fetal pancreas.
Domain
The RING-H2 zinc finger is an atypical RING finger with a His ligand in place of the fourth Cys of the classical motif (PubMed:20835242). The UBR-type zinc finger forms a pocket that mediates recognition of type 1 N-degrons (PubMed:20835242, PubMed:28392261). It exhibits preference for arginine in the first position, and a lower preference for lysine and histidine (PubMed:20835242). It binds N-degrons with a methylated arginine or lysine in the first position (PubMed:28392261).
Function
E3 ubiquitin-protein ligase which is a component of the N-end rule pathway (PubMed:15548684, PubMed:20835242, PubMed:28392261). Recognizes and binds to proteins bearing specific N-terminal residues (N-degrons) that are destabilizing according to the N-end rule, leading to their ubiquitination and subsequent degradation (PubMed:20835242, PubMed:28392261). Recognizes both type-1 and type-2 N-degrons, containing positively charged amino acids (Arg, Lys and His) and bulky and hydrophobic amino acids, respectively (PubMed:20835242, PubMed:28392261). Does not ubiquitinate proteins that are acetylated at the N-terminus (PubMed:20835242). In contrast, it strongly binds methylated N-degrons (PubMed:28392261). Plays a critical role in chromatin inactivation and chromosome-wide transcriptional silencing during meiosis via ubiquitination of histone H2A (By similarity). Binds leucine and is a negative regulator of the leucine-mTOR signaling pathway, thereby controlling cell growth (PubMed:20298436). Required for spermatogenesis, promotes, with Tex19.1, SPO11-dependent recombination foci to accumulate and drive robust homologous chromosome synapsis (By similarity). Polyubiquitinates LINE-1 retrotransposon encoded, LIRE1, which induces degradation, inhibiting LINE-1 retrotransposon mobilization (By similarity). Catalyzes ubiquitination and degradation of the N-terminal part of NLRP1 following NLRP1 activation by pathogens and other damage-associated signals: ubiquitination promotes degradation of the N-terminal part and subsequent release of the cleaved C-terminal part of NLRP1, which polymerizes and forms the NLRP1 inflammasome followed by host cell pyroptosis (By similarity). Plays a role in T-cell receptor signaling by inducing 'Lys-63'-linked ubiquitination of lymphocyte cell-specific kinase LCK (PubMed:38225265). This activity is regulated by DUSP22, which induces 'Lys-48'-linked ubiquitination of UBR2, leading to its proteasomal degradation by SCF E3 ubiquitin-protein ligase complex (PubMed:38225265).
Pathway
Protein modification; protein ubiquitination.
Post-translational modifications
Dephosphorylated by DUSP22 at Ser-1694 and Tyr-1697, leading to subsequent ubiquitination and proteasomal degradation.
'Lys-48'-linked ubiquitinated at Lys-94, Lys-779 and Lys-1599 following DUSP22-mediated dephosphorylation of Ser-1694 and Tyr-1697 which promotes UBR2 interaction with the SCF(FBW1A) E3 ubiquitin-protein ligase complex.
Sequence Similarities
Belongs to the E3 ubiquitin-protein ligase UBR1-like family.
Tissue Specificity
Broadly expressed, with highest levels in skeletal muscle, kidney and pancreas. Present in acinar cells of the pancreas (at protein level).
Cellular localization
- Nucleus
- Chromosome
- Associated with chromatin during meiosis.
Alternative names
C6orf133, KIAA0349, UBR2, E3 ubiquitin-protein ligase UBR2, N-recognin-2, Ubiquitin-protein ligase E3-alpha-2, Ubiquitin-protein ligase E3-alpha-II