| Protein Name | Voltage-Dependent Anion Channel 3 |
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| Gene | [VDAC3](/genes/vdac3) |
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| UniProt ID | Q9Y277 |
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| PDB ID | 4CMU, 4CNO |
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| Molecular Weight | ~34 kDa |
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| Subcellular Localization | Outer mitochondrial membrane, Plasma membrane |
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| Protein Family | VDAC/Porin family |
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VDAC3 (Voltage-Dependent Anion Channel 3) is a mitochondrial outer membrane protein that functions as a voltage-gated anion channel. VDAC3 is one of three VDAC isoforms in mammals (VDAC1, VDAC2, VDAC3) and plays critical roles in mitochondrial metabolism, apoptosis regulation, and cellular homeostasis. Recent research has implicated VDAC3 dysfunction in several neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and Huntington's disease [1].
¶ Domain Architecture
VDAC3 possesses the characteristic porin fold:
- β-barrel structure: 19 β-strands forming a cylindrical barrel
- N-terminal α-helix: Located inside the pore, involved in channel gating
- Loop regions: External loops contain binding sites for various ligands and proteins
- Ion selectivity filter: Determines channel permeability to anions vs. cations
- Voltage sensing mechanism: N-terminal helix responds to membrane potential changes
- Protein interaction interfaces: Multiple sites for binding mitochondrial proteins
- Phosphorylation: Tyrosine phosphorylation at multiple sites modulates channel activity
- Oxidation: Reactive oxygen species (ROS) can modify cysteine residues
- S-nitrosylation: Regulates VDAC3 function in response to nitric oxide signaling
VDAC3 functions as a voltage-dependent anion channel:
- Metabolite transport: Permits diffusion of ATP, ADP, metabolites across OMM
- Ion homeostasis: Regulates mitochondrial calcium and potassium levels
- ROS signaling: Controls release of mitochondrial ROS species
VDAC3 is essential for:
- ATP/ADP exchange: Facilitates cytosolic energy exchange
- Calcium signaling: Participates in mitochondrial calcium uptake
- Apoptosis regulation: Modulates release of cytochrome c and other pro-apoptotic factors
- Mitochondrial dynamics: Influences mitochondrial morphology and distribution
In neurons, VDAC3 is enriched in:
- Synaptic terminals
- Dendritic mitochondria
- Axonal compartments
VDAC3 supports neuronal energy demands, calcium buffering, and survival signaling.
VDAC3 contributes to AD pathogenesis through multiple mechanisms:
- Mitochondrial dysfunction: Altered VDAC3 activity leads to impaired energy metabolism
- Amyloid-beta interaction: Aβ can bind to VDAC3, disrupting channel function
- Calcium dysregulation: Impaired calcium handling contributes to excitotoxicity
- Apoptosis: VDAC3 dysregulation promotes neuronal apoptosis [2]
In PD, VDAC3 dysfunction is implicated in:
- Mitophagy impairment: Altered VDAC3 affects PINK1/Parkin-mediated mitophagy
- Mitochondrial DNA damage: VDAC3 dysfunction increases susceptibility to mtDNA damage
- Dopaminergic neuron vulnerability: Energy deficits accelerate degeneration [3]
VDAC3 plays a role in HD through:
- Metabolic deficits: Mutant huntingtin impairs VDAC3 function
- Mitochondrial dysfunction: Contributes to energy failure in striatal neurons
- Calcium dysregulation: Exacerbates excitotoxic cell death [4]
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VDAC modulators:
- VDAC-targeting peptides that restore channel function
- Small molecules that normalize VDAC3 activity
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Mitochondrial protective agents:
- Coenzyme Q10
- L-carnitine
- Alpha-lipoic acid
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Gene therapy approaches:
- VDAC3 overexpression vectors
- CRISPR editing to enhance VDAC3 expression
- isoform-specific targeting (VDAC1, VDAC2, VDAC3 have overlapping functions)
- Blood-brain barrier penetration
- Balancing channel activity (too open or too closed is problematic)
- VDAC structure and function in mitochondrial physiology (2019)
- VDAC in Alzheimer's disease pathogenesis (2020)
- Mitochondrial VDAC in Parkinson's disease (2021)
- VDAC and metabolic dysfunction in neurodegeneration (2018)
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