NADH Dehydrogenase 5 (MT-ND5) is a mitochondrial DNA-encoded subunit of Complex I (NADH:ubiquinone oxidoreductase) in the electron transport chain. It is one of the largest mtDNA-encoded proteins and plays a critical role in mitochondrial respiration. MT-ND5 mutations are associated with mitochondrial encephalomyopathies and neurodegenerative diseases.
| NADH Dehydrogenase 5 (MT-ND5) |
|---|
| Gene | [MT-ND5](/genes/mt-nd5) (mitochondrial) |
| UniProt | [P03915](https://www.uniprot.org/uniprot/P03915) |
| Molecular Weight | ~67 kDa |
| Subcellular Localization | Mitochondrial inner membrane |
| Protein Family | NADH dehydrogenase subunit 5 family |
MT-ND5 is a core membrane arm subunit of Complex I, the largest complex of the electron transport chain:
- NADH Oxidation: Catalyzes the oxidation of NADH
- Electron Transfer: Transfers electrons to ubiquinone
- Proton Pumping: Contributes to proton translocation across the inner membrane
- Q Binding Site: Part of the quinone binding tunnel
- Highly expressed in neurons and glial cells
- Essential for mitochondrial energy production in brain
- Critical for maintaining neuronal membrane potential
- MT-ND5 mutations are a common cause of MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes)
- A3243G mutation is the most common cause
- Stroke-like episodes are characteristic features
- MT-ND5 mutations can cause Leigh syndrome
- Characterized by bilateral basal ganglia lesions
- Progressive neurodegenerative course
- Complex I dysfunction is observed in AD brains
- MT-ND5 variants may modify disease risk
- Mitochondrial dysfunction contributes to amyloid pathology
- Complex I deficiency is a hallmark of PD
- MT-ND5 variants have been associated with PD risk
- PINK1/Parkin pathway affects Complex I quality control
- Coenzyme Q10: Electron carrier supplementation
- L-Arginine: May improve stroke-like episodes in MELAS
- Dichloroacetate: Metabolic regulator
- Mitochondrial replacement therapy
- Gene editing approaches for mtDNA
- Small molecule Complex I modulators
- MT-ND5 mutations in MELAS syndrome (2020)
- Complex I deficiency in Alzheimer's disease (2019)
- Mitochondrial DNA variants and Parkinson's disease (2021)