Ferritin Heavy Chain (FTH1)
<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Ferritin Heavy Chain (FTH1)</th>
</tr>
<tr>
<td class="label">Interactor</td>
<td>Relationship</td>
</tr>
<tr>
<td class="label">[Ferritin Light Chain](/proteins/ferritin-l)</td>
<td>Heteropolymer</td>
</tr>
<tr>
<td class="label">[IRP1/2](/genes/ireb2)</td>
<td>Post-transcriptional regulator</td>
</tr>
<tr>
<td class="label">[Nrf2](/proteins/nrf2)</td>
<td>Transcription factor</td>
</tr>
<tr>
<td class="label">[Transferrin](/proteins/transferrin)</td>
<td>Iron uptake</td>
</tr>
<tr>
<td class="label">[Ferroportin](/genes/fpn1)</td>
<td>Iron export</td>
</tr>
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<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">2 edges</a></td>
</tr>
</table>
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<h3 style="margin-top: 0; border-bottom: 1px solid #ccc;">FTH1 Protein</h3>
<ul style="list-style: none; padding: 0;"> [@muhoberac2019]
<li><strong>Gene:</strong> [FTH1](/genes/fth1)</li> [@adlard2008]
<li><strong>UniProt:</strong> [P02794](https://www.uniprot.org/uniprot/P02794)</li> [@stockwell2022]
<li><strong>Molecular Weight:</strong> ~21 kDa</li>
<li><strong>Subcellular Location:</strong> Cytoplasm, nucleus, mitochondria</li>
<li><strong>PDB Structures:</strong> [2FHA](https://www.rcsb.org/structure/2FHA), [4DZ0](https://www.rcsb.org/structure/4DZ0)</li>
</ul>
</div>
Overview
Mermaid diagram (expand to render)
Ferritin heavy chain (FTH1) is the ferroxidase component of ferritin, the primary intracellular iron storage complex. Together with ferritin light chain (FTL), FTH1 forms a 24-subunit spherical complex capable of storing up to 4,500 iron atoms. The ferroxidase activity of FTH1 converts toxic Fe2+ to Fe3+ for safe storage, playing a critical role in cellular iron homeostasis and protection against iron-mediated oxidative damage.
Structure
The ferritin complex consists of 24 subunits that self-assemble into a hollow spherical shell with 4-3-2 symmetry. FTH1 contributes ferroxidase activity through a di-iron center located in the four-helix bundle core:
- Four-helix bundle: The central structural motif containing the ferroxidase center
- Ferroxidase center: Binds two iron atoms and catalyzes Fe2+ oxidation
- Long loop: Connects helices B and C, involved in subunit interactions
- C-terminal E-helix: Contributes to inner cavity iron nucleation sites
The H:L subunit ratio determines ferritin properties, with H-rich ferritins having higher ferroxidase activity.
Normal Function
Iron Storage and Detoxification
FTH1 catalyzes the oxidation of Fe2+ to Fe3+ at the ferroxidase center, after which iron moves to the inner cavity for storage as ferrihydrite mineral. This dual function:
Removes toxic free iron that catalyzes Fenton reactions
Stores iron for future metabolic needs
Regulates iron bioavailability in response to cellular demandsIron-Independent Functions
FTH1 has emerging roles beyond iron storage:
- Cell proliferation: Supports rapid cell division through iron supply
- Development: Essential for embryogenesis in mice
- DNA protection: Shields nuclear DNA from iron-mediated damage
- Stress response: Upregulated by oxidative stress via Nrf2
Role in Neurodegeneration
Neurodegeneration with Brain Iron Accumulation (NBIA)
Ferritin dysfunction contributes to several NBIA disorders:
- Neuroferritinopathy: Mutations in FTL cause abnormal ferritin assembly and iron accumulation, though FTH1 is secondarily affected
- Aceruloplasminemia: Iron overload occurs despite normal ferritin, with ferritin becoming iron-saturated
- PKAN and PLA2G6: Secondary ferritin accumulation in iron-laden regions
Alzheimer's Disease
FTH1 is implicated in AD pathology through multiple mechanisms:
Amyloid-iron interactions: Ferritin colocalizes with amyloid plaques
Microglial iron handling: Activated [microglia](/cell-types/microglia-neuroinflammation) upregulate ferritin
Hippocampal vulnerability: Ferritin loss in vulnerable [neurons](/entities/neurons)
CSF ferritin elevation: Correlates with disease severityParkinson's Disease
Iron accumulation in the substantia nigra involves ferritin:
- Nigral ferritin reduction: Lower ferritin despite high iron
- Dopaminergic vulnerability: Low ferritin in vulnerable neurons
- [Ferroptosis](/entities/ferroptosis) susceptibility: Insufficient ferritin to handle iron load
Ferroptosis
FTH1 is a key ferroptosis regulator:
- Iron sequestration: Prevents lipid peroxidation by reducing labile iron
- Nrf2 target: Upregulated during ferroptosis as protective response
- Therapeutic target: Ferritin induction can suppress ferroptotic cell death
Therapeutic Targeting
Iron Chelation Therapy
Ferritin levels inform chelation strategies:
- Deferiprone: Can cross [BBB](/entities/blood-brain-barrier), may redistribute iron to ferritin
- Deferoxamine: Limited brain penetration
- Combined approaches: Chelation plus ferritin induction
Ferritin Induction Strategies
Approaches to boost ferritin for neuroprotection:
Nrf2 activators: Increase FTH1 transcription
Iron supplementation: In iron-deficient conditions
Gene therapy: FTH1 delivery to vulnerable neuronsBiomarker Potential
Ferritin serves as a biomarker:
- CSF ferritin: Elevated in neurodegenerative diseases
- Serum ferritin: Reflects systemic iron status
- MRI ferritin imaging: Emerging technique for brain iron assessment
Key Interactions
See Also
- [tau-protein](/proteins/tau) — Related [tau](/proteins/tau) kinase substrate in AD](/proteins)
- [amyloid-beta](/proteins/amyloid-beta-protein) — Related [APP](/entities/app-protein) cleavage product](/proteins)
- [GSK3B](/proteins/gsk3b) — Major kinase in neurodegeneration](/proteins)
- [CDK5](/genes/cdk5) — Another tau kinase](/genes)
- [BACE1](/entities/bace1) — Beta-secretase in amyloidogenesis
External Links
- [UniProt](https://www.uniprot.org/) - Protein sequence and functional data
- [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
- [PDB](https://www.rcsb.org/) - Protein structure data
References
[Unknown, Arosio and Levi, Cytosolic and mitochondrial ferritins in the pathophysiology of neurodegenerative diseases (2010) (2010)](https://doi.org/10.1083/jcb.200911013)
[Friedman et al., Ferritin forms with iron in Parkinson's disease (2022) (2022)](https://doi.org/10.1038/s41586-022-04737-3)
[Unknown, Muhoberac and Vidal, Iron, ferritin, hereditary ferritinopathy, and neurodegeneration (2019) (2019)](https://doi.org/10.3389/fnins.2019.01190)
[Adlard et al., Changes in ferritin levels in the brain in Alzheimer's disease (2008) (2008)](https://doi.org/10.1111/j.1471-4159.2008.05683.x)
[Unknown, Stockwell, Ferroptosis turns 10: Emerging mechanisms, physiological functions, and therapeutic applications (2022) (2022)](https://doi.org/10.1016/j.cell.2022.06.003)Pathway Diagram
The following diagram shows the key molecular relationships involving Ferritin Heavy Chain (FTH1) discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)