Anxa1 Protein — Annexin A1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
ANXA1 Protein
| Property | Value |
|----------|-------|
| **Protein Name** | Annexin A1 (Lipocortin-1) |
| **Gene Symbol** | ANXA1 |
| **UniProt ID** | P04083 |
| **Molecular Weight** | ~37 kDa |
| **Cellular Localization** | Cytoplasm, Cell Membrane, Extracellular |
| **Protein Family** | Annexin Family |
| **Structure** | 4 Annexin Repeats, N-terminal Region |
ANXA1 (Annexin A1), also known as lipocortin-1, is a calcium-dependent phospholipid-binding protein that belongs to the annexin family. Originally discovered as a glucocorticoid-induced protein with potent anti-inflammatory properties, Annexin A1 is now recognized as a multifunctional protein with roles in neuroprotection, neuroinflammation modulation, and synaptic plasticity. Its expression in neurons and glial cells makes it a key player in neurodegenerative disease pathogenesis.
Annexin A1 contains:
- N-terminal Region: Unique sequence, contains phosphorylation sites and interaction domains
- Four Annexin Repeats: Conserved calcium-dependent phospholipid-binding domains
- Phosphorylation Sites: Serine 27 (PKC), Serine 28 (PKC)
- Calcium-Binding Sites: EF-hand motifs in each repeat
The protein folds into a convex shape with the phospholipid-binding sites on the convex surface.
- Inhibits phospholipase A2 (PLA2)
- Reduces eicosanoid production
- Blocks neutrophil adhesion and migration
- Modulates cytokine release
- Calcium-dependent membrane binding
- Vesicle trafficking
- Exocytosis regulation
- Endocytosis modulation
- Promotes neuronal survival
- Modulates glial cell function
- Regulates neuroinflammation
- Supports synaptic plasticity
Annexin A1 is widely expressed in the nervous system:
In neurons, Annexin A1 localizes to synapses and is released in activity-dependent manner.
- Amyloid-β interaction: Modulates Aβ toxicity
- Neuroinflammation: Anti-inflammatory effects
- Synaptic function: Regulates glutamate release
- Therapeutic target: Annexin A1 mimetics
- Dopaminergic neuron protection
- α-Synuclein modulation
- Neuroinflammation: Anti-inflammatory
- Demyelination: Regulatory role
- Remyelination: Promotes oligodendrocyte function
- Autoimmunity: Immunomodulation
¶ Stroke and Ischemia
- Neuroprotection: Reduces infarct size
- Blood-brain barrier: Protects BBB integrity
- Anti-apoptotic: Prevents neuronal death
Annexin A1 acts through:
- Formyl Peptide Receptor (FPR1/ALX): G-protein coupled receptor
- EGFR Transactivation: Growth factor signaling
- S1PR1: Sphingosine-1-phosphate receptor
- PLA2 inhibition: Reduces prostaglandin synthesis
- ERK activation: Cell survival signaling
- NF-κB modulation: Anti-inflammatory
- Akt pathway: Pro-survival signals
Annexin A1-targeting strategies:
- Peptide mimetics: Ac2-26 and derivatives
- FPR agonists: Synthetic analogs
- Small molecules: Non-peptide agonists
- Gene therapy: AAV-mediated expression
- Stroke: Phase II trials
- Neurodegeneration: Preclinical
- Autoimmune disorders: Immunomodulation
- Pain: Analgesic effects
| Model |
Findings |
| ANXA1 Knockout |
Exaggerated inflammation |
| Transgenic ANXA1 |
Neuroprotection in models |
| Stroke Models |
40-60% reduction in infarct |
The study of Anxa1 Protein — Annexin A1 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.