Ube2V2 Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
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Protein Name: Ubiquitin-Conjugating Enzyme E2 Variant 2
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Gene: UBE2V2
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UniProt ID: P61077
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PDB Structure IDs: 1JAT, 2K6N, 3CMM
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Molecular Weight: 16.3 kDa
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Subcellular Localization: Cytoplasm, nucleus
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Protein Family: E2 ubiquitin-conjugating enzyme (UEV family)
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Expression: Ubiquitous; high in brain, heart, skeletal muscle
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Ubiquitin-Conjugating Enzyme E2 Variant 2 (UBE2V2), also known as UEV-2 or MMS2, is a member of the UEV (Ubiquitin E2 Variant) family. Unlike canonical E2 enzymes, UBE2V2 lacks the catalytic cysteine residue required for ubiquitin thioester formation, making it enzymatically inactive as a traditional E2 [1].
Instead, UBE2V2 functions as a scaffold and regulator in ubiquitin signaling pathways, particularly in:
- DNA damage repair (through PCNA and K63-linked polyubiquitination)
- NF-κB signaling
- Proteasomal degradation
- Innate immune responses [2]
In the brain, UBE2V2 plays important roles in neuronal survival, synaptic function, and responses to oxidative stress.
UBE2V2 belongs to the UEV family, which shares structural homology with E2 ubiquitin-conjugating enzymes but has distinct features:
¶ Domain Architecture
- UEV Domain: The core structure consists of a ubiquitin-conjugating (UBC) fold but lacks the catalytic cysteine
- Flexible C-terminal Tail: Contains sequences important for protein interactions
- Dimerization Interface: Can form homodimers and heterodimers with other UEV proteins
- α/β Fold: Similar to canonical E2 enzymes (14-16 kDa)
- Active Site Substitution: Contains Serine (Ser106) instead of catalytic cysteine
- PCNA-binding Surface: Key residues for PCNA interaction [3]
UBE2V2 forms:
- Homodimers: Functional in some contexts
- Heterodimers: With UBE2V1 (UEV-1), enhancing function
- Complexes with E2 Enzymes: Can modulate E2 activity [4]
UBE2V2 is a critical component of the error-free DNA damage tolerance pathway:
PCNA Monoubiquitination:
- Forms a complex with UBC13 (UBE2N) and E ligase
- Catalyzes K63-linked polyubiquitination of PCNA
- Signals for translesion synthesis or homologous recombination [5]
Role in DNA Repair:
- Facilitates repair of UV-induced DNA damage
- Prevents replication fork collapse
- Maintains genome stability
UBE2V2 modulates NF-κB activation:
TRAF6-Mediated Signaling:
- Interacts with TRAF6 and UBC13
- Required for K63-linked ubiquitination in NF-κB pathway
- Regulates inflammatory gene expression [6]
Immune Responses:
- Modulates cytokine production
- Affects macrophage activation
- Involved in bacterial and viral immune responses
Proteasome Regulation:
- Some evidence for involvement in proteasomal targeting
- May assist in degradation of misfolded proteins
- Role in ER-associated degradation (ERAD) [7]
In neurons:
- Localized to synaptic compartments
- May regulate synaptic protein turnover
- Involved in activity-dependent protein degradation
UBE2V2 alterations in AD brain include:
DNA Damage Accumulation:
- Neurons show increased DNA damage in AD
- UBE2V2 expression is altered, potentially affecting repair
- May contribute to neuronal loss [8]
Oxidative Stress:
- UBE2V2 responds to oxidative DNA damage
- Impaired function may exacerbate oxidative stress
- Mitochondrial dysfunction affects UBE2V2 activity [9]
Amyloid-β Effects:
In PD and dopaminergic neurons:
Mitochondrial Dysfunction:
- UBE2V2 participates in mitophagy regulation
- PINK1/Parkin pathway intersects with UBE2V2 signaling
- Altered in models of mitochondrial toxins [11]
α-Synuclein Metabolism:
- May assist in α-synuclein degradation
- Altered in Lewy body disease
- Implicated in proteostasis failure [12]
Neuroinflammation:
- NF-κB pathway dysregulation in PD
- UBE2V2 may modulate microglial responses
- Connected to chronic neuroinflammation [13]
Protein Aggregation:
- UBE2V2 expression altered in ALS
- May be sequestered into aggregates
- TDP-43 pathology affects ubiquitin system [14]
DNA Repair Deficits:
- Motor neurons are particularly vulnerable to DNA damage
- UBE2V2 dysfunction may contribute to accumulation
- Connected to C9orf72-mediated pathogenesis [15]
Mutant Huntingtin Effects:
Inflammatory Demyelination:
- UBE2V2 modulates NF-κB in immune cells
- May affect cytokine production
- Role in autoimmune pathogenesis [17]
The functional complex requires:
- UBE2N (UBC13): Catalytically active E2 enzyme
- UBE2V2 (MMS2): Scaffold/regulatory subunit
- E3 Ligases: TRAF6, RNF8, and others
This complex generates K63-linked polyubiquitin chains.
- Receptor activation (TLR, TNFR)
- TRAF6 recruitment and autoubiquitination
- UBE2N-UBE2V2 complex recruited
- K63-linked ubiquitination of substrates
- IKK complex activation
- NF-κB nuclear translocation [6]
- PCNA monoubiquitination by RAD6
- UBE2N-UBE2V2 recruited
- K63-linked polyubiquitination of PCNA
- Recruitment of translesion polymerases
- Error-free repair completion [5]
| Approach |
Target |
Status |
Notes |
| UBC13 inhibitors |
UBE2N-UBE2V2 |
Preclinical |
Blocks K63 ubiquitination |
| NF-κB modulators |
UBE2V2 pathway |
Research |
Anti-inflammatory |
| Proteostasis enhancers |
UBE2V2 function |
Exploratory |
May help protein clearance |
- Viral vector delivery of UBE2V2
- siRNA targeting pathological pathways
- CRISPR-based approaches (future) [18]
- Brain UBE2V2: Altered expression in AD, PD, ALS
- Blood/CSF: May serve as biomarker for DNA repair capacity
- Activity assays: K63-linked ubiquitination measurement [19]
Ube2V2 Protein plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.
The study of Ube2V2 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.