Endonuclease G (ENDOG) is a mitochondrial endonuclease that plays a critical role in apoptosis and mitochondrial DNA maintenance. Originally discovered as a mitochondrial protein involved in DNA fragmentation during programmed cell death, ENDOG has been implicated in various neurodegenerative diseases.
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| Gene | [ENDOG](/genes/endog) |
|---|
| UniProt ID | Q14249 |
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| Protein Family | Endonuclease G family |
|---|
| Molecular Weight | ~30 kDa |
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| Subcellular Localization | Mitochondria (intermembrane space) |
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| Expression | High in heart, liver, brain |
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ENDOG is a nuclear-encoded mitochondrial protein with the following structural features:
- N-terminal mitochondrial targeting sequence (MTS): 27 amino acid transit peptide
- Helix-turn-helix domain: DNA binding region
- Catalytic domain: Contains the active site for nuclease activity
- Conserved motif: His-Asp-Glu (catalytic triad)
In the normal nervous system, ENDOG functions in:
- Mitochondrial DNA maintenance: Involved in mtDNA replication and repair
- Apoptosis initiation: Releases from mitochondria during early apoptosis
- Cellular stress response: Handles oxidative DNA damage
- Development: Important during neural development
In AD, ENDOG is involved in:
- Neuronal apoptosis induced by amyloid-beta (Aβ)
- Mitochondrial dysfunction in AD neurons
- Caspase-independent cell death pathways [1]
- Elevated in AD brain tissue [2]
In PD, ENDOG contributes to:
- Mitochondrial complex I deficiency
- Dopaminergic neuron death
- Alpha-synuclein-induced toxicity
- Mitochondrial permeability transition [3]
In ALS:
- Mitochondrial dysfunction in motor neurons
- Release from damaged mitochondria
- Contributes to non-canonical cell death
- Interaction with TDP-43 pathology [4]
In HD:
- Elevated ENDOG activity in striatal neurons
- Contributes to mitochondrial dysfunction
- Early neuronal death mechanisms [5]
- Inhibitors: Small molecules blocking ENDOG release/activity
- Mitochondrial protectants: Compounds preventing mitochondrial permeabilization
- Gene therapy: Modulating ENDOG expression
- Preclinical validation ongoing
- No clinical trials yet
- Mitochondrial targeting shows promise
| Partner |
Interaction Type |
Function |
| AIF |
Co-release |
Apoptosis-inducing factor |
| BCL2 |
Regulation |
Anti-apoptotic control |
| VDAC |
Channel |
Mitochondrial release |
| CypD |
Interaction |
Permeability transition |