A9 dopaminergic neurons uniquely co-express TFEB and TFE3 at high levels, with TFE3 serving as a compensatory backup transcription factor for TFEB under lysosomal stress. In GBA1 deficiency, TFEB activation initially upregulates the CLEAR network to restore lysosomal biogenesis. However, in these neurons, this compensatory response fails because the newly synthesized LAMP2A protein cannot properly integrate into lysosomal membranes due to a concurrent defect in VPS35-mediated trafficking. The accumulated LAMP2A instead gets shunted to the proteasome for degradation. This creates a paradox: TFEB/TFE3 activation increases transcription of lysosomal genes, but the executors (LAMP2A, GCase, cathepsins) fail to reach functional lysosomes. A10 neurons (resilient) avoid this trap because they have higher basal VPS35 expression and more efficient retrieval of LAMP2A from early endosomes. In GBA1-deficient A9 neurons, the sustained TFEB/TFE3 activation eventually exhausts the transcriptional coactivator EP300/CBP, leading to a collapse in lysosomal gene expression at disease onset.
...Curated pathway from expert analysis
flowchart TD
A["GBA1 Deficiency<br/>Lysosomal Stress"]
B["TFEB CLEAR Network Activation<br/>Lysosomal Biogenesis Attempt"]
C["TFE3 Compensatory Switch<br/>Backup Transcription Factor"]
D["VPS35 Trafficking Defect<br/>LAMP2A Delivery Failure"]
E["New Lysosomes Lack CMA Competence<br/>Stress Response Ineffective"]
F["SNCA and GlcCer Burden Persists<br/>Dopaminergic Stress"]
G["A9 Neuron Vulnerability<br/>PD Progression"]
A --> B
B --> C
C --> E
D --> E
E --> F
F --> G
style B fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
style G fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9aNo linked papers recorded for this hypothesis yet.
No curated PDB or AlphaFold mapping for TFEB yet. Search RCSB →
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 TFEB.
Run python3 scripts/backfill_hypothesis_depmap.py to populate.
No resource usage or linked notebooks recorded for this hypothesis yet.
| Prediction | Predicted | Observed | Status | Conf |
|---|---|---|---|---|
| IF lysosomal stress is induced in A9 neurons (via GBA1 knockout or chloroquine treatment) while A10 neurons remain unstressed, THEN RNA-seq time-course will reveal that A9 neurons show biphasic CLEAR | A9 neurons exhibit ≥2-fold upregulation of TFEB/TFE3 target genes (LAMP1, LAMP2, CTSB, GBA) at day 3, then regression to baseline or below at day 7; A10 neurons | — no observation — | pending | 0.68 |
| IF VPS35 is pharmacologically upregulated (e.g., via small molecule activator or viral vector) in GBA1-deficient A9 dopaminergic neurons, THEN lysosomal membrane LAMP2A protein levels will increase by | Increased LAMP2A localization to lysosomal membranes (measured by subcellular fractionation Western blot or immunocytochemistry) and reduced ubiquitinated LAMP2 | — no observation — | pending | 0.75 |