TBK1 Loss Drives Motor Neuron Death Through Impaired Mitophagy and Metabolic Collapse
🧪 Overview
This hypothesis proposes that loss-of-function mutations in TBK1 contribute to ALS pathogenesis primarily through disrupted mitochondrial quality control in motor neurons, leading to bioenergetic failure and selective neuronal death. TBK1 normally phosphorylates autophagy receptors OPTN and p62, which are essential for targeting damaged mitochondria for mitophagy. When TBK1 function is lost, defective mitochondria accumulate in motor neurons, causing oxidative stress, ATP depletion, and ultimately cell death. Supporting evidence includes phospho-proteome profiling in human neurons (Smeyers et al., Cell Rep 2025) showing that ALS/FTD-associated TBK1 substrates are predominantly neuronal autophagy proteins (FIP200, OPTN, p62) rather than inflammatory mediators. Motor neurons are particularly vulnerable due to their high metabolic demands, long axonal projections requiring extensive mitochondrial transport, and limited regenerative capacity. The 2025 Nat Commun study, while highlighting microglial changes, may reflect secondary neuroinflammation responding to primary motor neuron damage rather than the initiating pathogenic event.
...🧬 Mechanism
Curated pathway from expert analysis
flowchart TD
A["dsDNA/dsRNA or Bacteria<br/>STING/MAVS Signal"]
B["TBK1 Activation<br/>IKK-epsilon Complex"]
C["IRF3 Phosphorylation<br/>Ser396 by TBK1"]
D["IRF3 Dimerization<br/>Nuclear Import"]
E["Type-I IFN Expression<br/>IFN-beta/IFN-alpha"]
F["Antiviral Defense<br/>ISG Upregulation"]
G["TBK1 Loss-of-Function<br/>ALS10 Mutations"]
H["OPTN/p62 Phosphorylation<br/>Selective Autophagy"]
A --> B
B --> C
B --> H
C --> D
D --> E
E --> F
G -.->|"impairs"| B
G -.->|"impairs"| H
style A fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
style F fill:#1b5e20,stroke:#81c784,color:#81c784
style G fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a⚖️ Evidence
No linked papers recorded for this hypothesis yet.
🏥 Translation
🧬 3D Protein Structure — TBK1
No curated PDB or AlphaFold mapping for TBK1 yet. Search RCSB →
🧠 GTEx v10 Brain ExpressionJSON
Median TPM across 13 brain regions for TBK1 → OPTN / p62 / FIP200 / mitophagy machinery from GTEx v10.
💉 Clinical Trials
No clinical trials data linked to this hypothesis yet.
No curated ClinVar variants loaded for this hypothesis.
Run scripts/backfill_clinvar_variants.py to fetch P/LP/VUS variants.
No DepMap CRISPR Chronos data found for TBK1 → OPTN.
Run python3 scripts/backfill_hypothesis_depmap.py to populate.
🏆 Tournament
🏆 Arenas / Elo
📊 Market Indicators
💾 Resource Usage
▸Metadatasource: v1_phase_c_backfill · origin_type: gap_debate
| source | v1_phase_c_backfill |
| origin_type | gap_debate |
| _schema_version | 1 |