Exposed amyloidogenic segments trigger CHIP-mediated oligomer-selective ubiquitination through HSP70 conformational switching
🧪 Overview
This hypothesis proposes that HSP70's recognition of exposed β-sheet propensity sequences in amyloidogenic proteins serves as the molecular trigger for CHIP-mediated selective degradation of pathological oligomers. When amyloidogenic segments (typically 5-15 hydrophobic residues with high β-sheet propensity) become exposed during protein misfolding, they are recognized by HSPA8's substrate-binding domain through their distinct physicochemical properties. This recognition event induces a specific conformational change in HSP70 that acts as a molecular switch, stabilizing the HSP70-CHIP complex through enhanced TPR-EEVD interactions and allosteric modifications of the ATPase domain. The key insight is that oligomeric pathological conformers expose multiple amyloidogenic segments simultaneously, creating a multivalent binding surface that prolongs HSP70-CHIP engagement compared to monomeric species or transient folding intermediates. This sustained complex formation promotes polyubiquitination of lysine residues on the oligomeric substrate through CHIP's U-box E3 ligase activity.
...🧬 Mechanism
Curated pathway from expert analysis
flowchart TD
A["HSPA8, HSPA1A, DNAJB6, DNAJB2<br/>Hypothesis Target"]
B["Aggregation<br/>Cited Mechanism"]
C["Cellular Response<br/>Stress or Clearance Change"]
D["Neural Circuit Effect<br/>Synapse/Glia Vulnerability"]
E["Neurodegeneration<br/>Disease-Relevant Outcome"]
A --> B
B --> C
C --> D
D --> E
style A fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
style B fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a
style E fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a⚖️ Evidence
No linked papers recorded for this hypothesis yet.
🏥 Translation
🧬 3D Protein Structure — STUB1
No curated PDB or AlphaFold mapping for STUB1 yet. Search RCSB →
🧠 GTEx v10 Brain ExpressionJSON
Median TPM across 13 brain regions for STUB1 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 STUB1.
Run python3 scripts/backfill_hypothesis_depmap.py to populate.
🏆 Tournament
🏆 Arenas / Elo
📊 Market Indicators
💾 Resource Usage
▸Metadatasource: v1_phase_c_backfill · origin_type: debate_synthesizer
| source | v1_phase_c_backfill |
| origin_type | debate_synthesizer |
| _schema_version | 1 |