The activity-dependent synaptic tagging mechanism operates through coordinated interplay of CREB1, IGF1 (insulin-like growth factor 1), and IGF1R (insulin-like growth factor 1 receptor) signaling cascades. Neural activity-induced calcium influx activates CaMKIV and PKA, which phosphorylate CREB1 at serine 133, enabling binding to CRE sites in target gene promoters. Phosphorylated CREB1 initiates transcription of IGF1, which contains multiple CRE-responsive elements in its promoter region. IGF1 synthesis produces a precursor protein that undergoes post-translational processing to generate mature IGF1, packaged into secretory vesicles and released through activity-dependent mechanisms. The secreted IGF1 binds to IGF1R on synaptic membranes, triggering receptor autophosphorylation at tyrosine residues and recruitment of insulin receptor substrate proteins (IRS1/2). IGF1R activation initiates the PI3K/Akt/mTOR pathway, which promotes protein synthesis essential for synaptic maintenance and enhances CREB phosphorylation through mTORC1-dependent S6K1 activation.
...Curated pathway from expert analysis
flowchart TD
A["Target Gene: CREB1 BDNF NTRK2 TrkB"]
B["Molecular Mechanism<br/>Pathway Activation"]
C["Cellular Phenotype<br/>Neuronal / Glial Response"]
D["Network Effect<br/>Circuit-Level Consequence"]
E["Disease Relevance<br/>Neurodegeneration Link"]
A --> B --> C --> D --> E
style A fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
style E fill:#1b5e20,stroke:#81c784,color:#81c784No linked papers recorded for this hypothesis yet.
No curated PDB or AlphaFold mapping for CREB1 yet. Search RCSB →
Median TPM across 13 brain regions for CREB1, IGF1, IGF1R 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 CREB1, IGF1, IGF1R.
Run python3 scripts/backfill_hypothesis_depmap.py to populate.