This hypothesis proposes that targeted enhancement of VPS26A subunit expression and stability can rescue retromer complex dysfunction by improving the structural integrity and assembly efficiency of the VPS26/VPS29/VPS35 heterotrimer. Unlike approaches focusing on VPS35 restoration, this strategy targets the cargo recognition subunit VPS26A, which serves as the critical interface between the retromer core and cargo-selective sorting nexins. The mechanism involves VPS26A-mediated stabilization of the entire retromer complex through enhanced protein-protein interactions at the endosomal membrane. Specifically, increased VPS26A levels would promote more robust binding between the cargo recognition domain and sorting nexin dimers (SNX1/SNX2 or SNX5/SNX6), leading to improved retrograde transport from endosomes to the trans-Golgi network. This approach addresses the fundamental assembly defects observed in neurodegenerative diseases where retromer dysfunction contributes to pathological protein accumulation. The intervention would utilize VPS26A overexpression vectors or small molecule stabilizers that enhance VPS26A folding and membrane recruitment.
...Curated pathway from expert analysis
flowchart TD
A["VPS35-VPS26-VPS29<br/>Retromer Core Trimer"]
B["Endosomal Cargo Recognition<br/>CI-MPR/ATG9/SorLA Retrieval"]
C["Retrograde Trafficking<br/>Endosome-to-TGN"]
D["WASH Complex Recruitment<br/>Actin Branching on Endosome"]
E["Cathepsin D Maturation<br/>Lysosomal Hydrolase Sorted"]
F["VPS35 D620N Mutation<br/>Parkinson's PARK17"]
G["Lysosomal Dysfunction<br/>Alpha-Synuclein Accumulation"]
A --> B
B --> C
C --> D
C --> E
F -.->|"impairs"| A
F --> G
style A fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
style E fill:#1b5e20,stroke:#81c784,color:#81c784
style F fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a
style G fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9aNo linked papers recorded for this hypothesis yet.
No curated PDB or AlphaFold mapping for VPS26A yet. Search RCSB →
Median TPM across 13 brain regions for VPS26A from GTEx v10.
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 VPS26A.
Run python3 scripts/backfill_hypothesis_depmap.py to populate.
| Prediction | Predicted | Observed | Status | Conf |
|---|---|---|---|---|
| IF VPS26A is overexpressed (2-fold above endogenous levels) in human iPSC-derived neurons via AAV-mediated transduction, THEN retromer complex assembly will increase by ≥30% (measured by co-immunoprec | ≥30% increase in VPS26/VPS29/VPS35 heterotrimer complex formation detected by quantitative co-immunoprecipitation | — no observation — | pending | 0.65 |
| IF a small molecule VPS26A stabilizer (10μM, daily for 14 days) is administered to a mouse model of retromer dysfunction (Vps35 D620N knock-in), THEN mannose-6-phosphate receptor (M6PR) trafficking to | ≥70% restoration of M6PR colocalization with TGN46 (trans-Golgi marker) compared to wild-type controls, quantified by confocal microscopy | — no observation — | pending | 0.55 |