ZAP70 (Zeta Chain T-Cell Receptor Associated Protein Kinase 70) is a tyrosine kinase essential for T-cell receptor (TCR) signaling and adaptive immunity. While primarily studied in immune cells, ZAP70 has emerging roles in neuroinflammation—a key contributor to neurodegenerative disease pathogenesis.
| Symbol | ZAP70 |
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| Full Name | Zeta Chain T-Cell Receptor Associated Protein Kinase 70 |
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| Aliases | SRK, TZK, STD |
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| Chromosomal Location | Chromosome 2q11.82 |
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| NCBI Gene ID | 7535 |
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| OMIM | 176947 |
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| Ensembl ID | ENSG00000120217 |
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| UniProt ID | P43403 |
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| Protein Class | Tyrosine Kinase / Non-Receptor Kinase |
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¶ Protein Structure and Function
¶ Domain Architecture
ZAP70 is a member of the Syk family of tyrosine kinases:
- N-terminal tandem SH2 domains: Bind to phosphorylated ITAM motifs on TCR ζ-chain
- Interdomain A: Regulatory region
- Kinase domain: Catalytic activity (C-terminal)
- C-terminal proline-rich region: Protein-protein interactions
- TCR engagement leads to Src-family kinase activation
- ITAM phosphorylation creates docking sites for ZAP70
- SH2 domain binding recruits ZAP70 to the receptor complex
- Autophosphorylation activates kinase activity
- Downstream signaling through LAT, SLP-76 complex
- LAT: Linker for activation of T cells
- SLP-76: Adapter protein
- Vav: GEF for Rho family GTPases
- PLC-γ1: Phospholipase C activation
- Peripheral T-cell activation: ZAP70-mediated T-cell responses may contribute to neuroinflammation in AD
- Adaptive immunity: T-cell infiltration into brain parenchyma observed in AD patients
- ** cytokine production**: ZAP70+ T cells can produce pro-inflammatory cytokines
- Therapeutic implications: Immunomodulatory strategies targeting T-cell activation
- Neuroinflammation: Chronic neuroinflammation drives PD progression
- T-cell involvement: α-Synuclein-specific T cells may exhibit ZAP70-dependent activation
- Blood-brain barrier: T-cell trafficking may be influenced by ZAP70 signaling
- Microglial crosstalk: T-cell-derived cytokines activate microglia
- T-cell dysregulation: Altered T-cell responses in ALS patients
- ZAP70+ T cells: Infiltrating T cells may contribute to motor neuron injury
- Regulatory T cells: Tregs with altered ZAP70 signaling in ALS
- Direct relevance: ZAP70 is central to MS pathogenesis
- Therapeutic targeting: ZAP70 inhibitors investigated for MS treatment
The brain can modulate peripheral immune responses through the vagus nerve:
- Acetylcholine release from T cells
- α9α10 nAChR signaling on macrophages
- ZAP70-independent pathway: This contrasts with ZAP70-mediated T-cell activation
Understanding the balance between:
- Pro-inflammatory: ZAP70-mediated T-cell activation
- Anti-inflammatory: Cholinergic signaling
...may lead to novel immunomodulatory therapies.
- ATP-competitive inhibitors: Purvalanol A, PP1
- Allosteric inhibitors: Under development
- SH2 domain blockers: Prevent ITAM binding
- Autoimmune diseases: ZAP70 inhibitors for rheumatoid arthritis, lupus
- Transplantation: Immunosuppressive therapy
- Neurodegeneration: Indirect targeting through immunomodulation