ID: h-b262f4c9d8
Hypothesis

p62 Liquid-Liquid Phase Separation Nucleates Cross-Organelle Cargo for Coordinated Autophagy

p62 Liquid-Liquid Phase Separation Nucleates Cross-Organelle Cargo for Coordinated Autophagy starts from the claim that modulating SQSTM1/p62 (SQSTM1), ULK1/FIP200 within the disease context of neurodegeneration can redirect a disease-re.
🧬 SQSTM1/p62 (SQSTM1), ULK1/FIP200🩺 neurodegeneration🎯 Composite 65%💱 $0.57▼11.5%proposed
EvidencePending (0%)📖 0 cit🗣 1 debates 5 support 3 oppose
✓ All Quality Gates Passed
Mechanistic 0.68 (15%) Evidence 0.68 (15%) Novelty 0.85 (12%) Feasibility 0.58 (12%) Impact 0.65 (12%) Druggability 0.45 (10%) Safety 0.60 (8%) Competition 0.80 (6%) Data Avail. 0.65 (5%) Reproducible 0.55 (5%) KG Connect 0.50 (8%) 0.649 composite

🧪 Overview

Mechanistic Overview


p62 Liquid-Liquid Phase Separation Nucleates Cross-Organelle Cargo for Coordinated Autophagy starts from the claim that modulating SQSTM1/p62 (SQSTM1), ULK1/FIP200 within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: "## Mechanistic Overview p62 Liquid-Liquid Phase Separation Nucleates Cross-Organelle Cargo for Coordinated Autophagy starts from the claim that modulating SQSTM1/p62 (SQSTM1), ULK1/FIP200 within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: "## Mechanistic Overview p62 Liquid-Liquid Phase Separation Nucleates Cross-Organelle Cargo for Coordinated Autophagy starts from the claim that p62 undergoes LLPS upon phosphorylation (Ser403) and ubiquitination of bound cargo, forming droplets that concentrate ubiquitinated proteins from multiple organelles (mitochondria, ER, protein aggregates) into a single autophagosomal capture event. This 'mixed garbage collection' allows coordinated multi-organelle clearance. The Keap1-p62 axis also links autophagy to NRF2 antioxidant response.

...

🧬 Mechanism

🧬 Curated Mechanism Pathway

Curated pathway from expert analysis

flowchart TD
    A["Ubiquitinated Cargo<br/>Misfolded Proteins/Organelles"]
    B["SQSTM1/p62 UBA Domain<br/>Ubiquitin Chain Recognition"]
    C["SQSTM1 Oligomerization<br/>LIR Motif Exposure"]
    D["LC3-II Interaction<br/>Autophagosome Docking"]
    E["Cargo Sequestration<br/>Autophagosome Engulfment"]
    F["NRF2 Release<br/>KEAP1-p62 Competition"]
    G["Lysosomal Degradation<br/>Proteostasis Restored"]
    H["SQSTM1 Aggregates<br/>ALS/FTD Pathology"]
    A --> B
    B --> C
    C --> D
    D --> E
    E --> G
    B --> F
    F -.->|"antioxidant"| G
    C --> H
    style A fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a
    style G fill:#1b5e20,stroke:#81c784,color:#81c784
    style H fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a

⚖️ Evidence

⚖️ Evidence Matrix5 supports3 contradicts
Supports
p62 LLPS required for selective autophagy
Supports
p62 body formation captures both mitochondria and ER in neuroprotection
Supports
Keap1-p62 axis links autophagy to NRF2 antioxidant response
Supports
p62 deletion causes mitochondrial and ER dysfunction in mice
Supports
p62 phosphorylated at Ser403 by CK2/TBK1 enhances aggregate clearance
Contradicts
Individual p62 droplets containing both organelles unproven - could be adjacent separate droplets
Contradicts
Different ubiquitin chain types may partition organelles into distinct droplets
Contradicts
p62's primary function may be aggregate clearance, not dynamic organelle QC
📖 Linked Papers

No linked papers recorded for this hypothesis yet.

🏥 Translation

🧬 3D Protein Structure — SQSTM1

No curated PDB or AlphaFold mapping for SQSTM1 yet. Search RCSB →

🧠 GTEx v10 Brain ExpressionJSON

Median TPM across 13 brain regions for SQSTM1/p62 (SQSTM1), ULK1/FIP200 from GTEx v10.

Cerebellar Hemisphere74.9 Cerebellum67.7 Frontal Cortex BA939.9 Spinal cord cervical c-137.2 Cortex36.7 Hypothalamus30.4 Anterior cingulate cortex BA2430.1 Substantia nigra30.1 Nucleus accumbens basal ganglia29.4 Caudate basal ganglia27.3 Amygdala25.5 Putamen basal ganglia24.9 Hippocampus23.0median TPM (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.

🔍 Search ClinVar for SQSTM1 →

No DepMap CRISPR Chronos data found for SQSTM1.

Run python3 scripts/backfill_hypothesis_depmap.py to populate.

💰 Estimated Development
Cost
$0
Timeline

🏆 Tournament

🏆 Arenas / Elo

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📊 Market Indicators

7d Trend
Falling
7d Momentum
▼ 1.1%
Volatility
Low
0.0035
Events (7d)
3
Price History
▼11.5%

💾 Resource Usage

LLM Tokens
26,692
$0.0801
Total Cost
$0.0801

🔮 Predictions

🔎 Predictions vs Observations2 predictions · 0 with recorded observations
PredictionPredictedObservedStatusConf
IF p62 LLPS is blocked by mutating the UBA domain (G311A) to prevent ubiquitin binding and Ser403 phosphorylation site to prevent phosphorylation in iPSC-derived neurons, THEN the co-localization of uMulti-organelle cargo co-localization within p62 droplets will decrease by >50%, and separate organelles will be cleared independently rather than coordinately,— no observation —pending0.72
IF p62 LLPS is enhanced by expressing a phosphomimetic S403E mutant or by increasing p62 expression 2-3 fold specifically in neurons of a TDP-43 proteinopathy mouse model (TARDBP A315T or Q331K), THENNeuronal TDP-43 aggregate burden will decrease by >30% and NRF2 antioxidant response genes will be upregulated by >50%, with improved motor performance on rotar— no observation —pending0.68
🔮 Falsifiable Predictions (2)
pendingconf 72%
IF p62 LLPS is blocked by mutating the UBA domain (G311A) to prevent ubiquitin binding and Ser403 phosphorylation site to prevent phosphorylation in iPSC-derived neurons, THEN the co-localization of ubiquitinated proteins from distinct organelles (mitochondria marked by TOMM20, ER marked by calnexin
Predicted outcome: Multi-organelle cargo co-localization within p62 droplets will decrease by >50%, and separate organelles will be cleared independently rather than coo
Falsification: Multi-organelle cargo continues to be coordinately cleared with normal kinetics despite p62 LLPS disruption, indicating redundant pathways compensate for the loss of p62-mediated droplet formation.
pendingconf 68%
IF p62 LLPS is enhanced by expressing a phosphomimetic S403E mutant or by increasing p62 expression 2-3 fold specifically in neurons of a TDP-43 proteinopathy mouse model (TARDBP A315T or Q331K), THEN neuronal clearance of TDP-43 aggregates will increase by >30% compared to littermate controls expre
Predicted outcome: Neuronal TDP-43 aggregate burden will decrease by >30% and NRF2 antioxidant response genes will be upregulated by >50%, with improved motor performanc
Falsification: TDP-43 aggregate clearance and NRF2 activation remain unchanged or worsen despite enhanced p62 LLPS, indicating p62 droplets are not rate-limiting for aggregate clearance in TDP-43 proteinopathy or th

📖 References (5)

  1. Phospho-dependent phase separation of FMRP and CAPRIN1 recapitulates regulation of translation and deadenylation.
    ["Kim et al.. Science (New York, N.Y.) (2019)
  2. Yellow fever in Brazil threatens successful recovery of endangered golden lion tamarins.
    ["Dietz et al.. Scientific reports (2019)
  3. p38 Mitogen activated protein kinase (MAPK): a new therapeutic target for reducing the risk of adverse pregnancy outcomes.
    ["Menon et al.. Expert opinion on therapeutic targets (2016)
  4. Subcellular transcriptomes and proteomes of developing axon projections in the cerebral cortex.
    ["Poulopoulos et al.. Nature (2019)
  5. The impact of isolated obesity on right ventricular function in young adults.
    ["Sokmen et al.. Arquivos brasileiros de cardiologia (2013)
Metadatasource: v1_phase_c_backfill · origin_type: debate_synthesizer
sourcev1_phase_c_backfill
origin_typedebate_synthesizer
_schema_version1
📊 Evidence Profile
Evidence Balance
+0%
Certainty
0%
Debates
0
Incoming
0
Outgoing
0
0 supporting 0 contradicting 0 neutral
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