TIC1 Protein (Mitochondrial Iron Import Context)
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<tr><th colspan="2" style="text-align:center;">TIC1 Protein</th></tr>
<tr><td><strong>Current Wiki Label</strong></td><td>TIC1 (provisional mitochondrial iron-import context page)</td></tr>
<tr><td><strong>Closest Human Axis</strong></td><td>Mitoferrin pathway (SLC25A37 / SLC25A28)</td></tr>
<tr><td><strong>Core Biology</strong></td><td>Mitochondrial iron uptake, heme and Fe-S cluster biogenesis</td></tr>
<tr><td><strong>Primary Relevance</strong></td><td>Oxidative stress, ferroptosis pressure, mitochondrial vulnerability</td></tr>
<tr><td><strong>Related Mechanisms</strong></td><td>[Iron metabolism](/mechanisms/iron-metabolism), [mitochondrial dysfunction](/mechanisms/mitochondrial-dysfunction)</td></tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>
</div>
Overview
This page tracks the mitochondrial iron-import mechanism under the current `TIC1` label used in parts of NeuroWiki. In mammals, the best-established mitochondrial iron importers are mitoferrin proteins (SLC25A37 and SLC25A28), while yeast ortholog systems include Mrs3/Mrs4.[@mhlenhoff2003][@shaw2006][@paradkar2009] The mechanistic importance for neurodegeneration is high: mitochondrial iron excess or miscompartmentalization can drive [reactive oxygen species](/entities/reactive-oxygen-species) generation, respiratory-chain impairment, and [ferroptosis](/entities/ferroptosis)-prone states.[@stockwell2017][@belaidi2016]
Nomenclature and Interpretation Note
Because "TIC1" nomenclature can be ambiguous across databases/species, claims on this page are intentionally anchored to well-supported mitochondrial iron import biology rather than to a single unresolved symbol mapping. The disease-relevant mechanism is still actionable and should be cross-linked to [iron metabolism](/mechanisms/iron-metabolism), [ferroptosis](/mechanisms/ferroptosis-neurodegeneration), and [mitochondrial dysfunction](/mechanisms/mitochondrial-dysfunction).
Core Mitochondrial Iron-Import Biology
Why mitochondrial iron transport matters
Mitochondria require iron for two central outputs:
- heme synthesis,
- iron-sulfur (Fe-S) cluster assembly.
Both outputs are essential for respiratory-chain enzymes and multiple metabolic proteins.[@shaw2006][@paradkar2009][@rouault2016]
Transport architecture
Evidence from yeast and mammalian systems supports a conserved concept: dedicated inner-membrane carriers move iron into the mitochondrial matrix where scaffold proteins and assembly systems partition iron into heme and Fe-S pathways.[@mhlenhoff2003][@shaw2006][@rouault2016]
Homeostatic balance problem
Insufficient import impairs energy metabolism and Fe-S biology, while excess import promotes redox-active iron accumulation and oxidative injury. Neurodegenerative risk often emerges from this imbalance, not simply from "high" or "low" iron alone.[@stockwell2017][@belaidi2016]
Neurodegeneration-Relevant Mechanisms
Parkinson disease
Substantia nigra pars compacta shows reproducible iron dyshomeostasis in Parkinson disease, and mitochondrial vulnerability in dopaminergic [neurons](/entities/neurons) amplifies injury from redox-active iron pools.[@dexter1989][@ward2014] Iron-dependent oxidative stress can reinforce [alpha-synuclein](/proteins/alpha-synuclein) misfolding and mitochondrial failure loops.
Alzheimer disease
Alzheimer brains show region-specific iron accumulation and disturbed iron-handling signatures. Mitochondrial iron stress can exacerbate lipid peroxidation, proteostasis burden, and synaptic failure.[@belaidi2016][@raven2013]
Friedreich ataxia and Fe-S pathway disorders
Friedreich ataxia provides a high-confidence disease model linking defective mitochondrial iron handling to Fe-S biogenesis failure, respiratory dysfunction, and selective neuronal/cardiac vulnerability.[@pandolfo2013]
Ferroptosis interface
Ferroptosis is a regulated cell-death state driven by iron-dependent lipid peroxidation. Mitochondrial iron flux and buffering status can modify ferroptotic sensitivity in stressed neural systems.[@stockwell2017][@do2016]
Translational Implications
Chelation and redistribution approaches
Brain-penetrant iron modulators (for example deferiprone) have been tested in neurodegeneration to lower pathological redox-active pools, though efficacy and safety depend strongly on disease stage and target tissue.[@devos2014]
Mitochondria-specific strategy space
Future strategy classes include:
- targeted iron redistributors rather than indiscriminate depletion,
- modulation of mitochondrial import/export regulators,
- combined use with antioxidant or mitochondrial-quality-control interventions.
Key risk
Overcorrection can worsen Fe-S and heme insufficiency. Therapeutic design must preserve essential mitochondrial iron use while reducing toxic iron chemistry.
Practical Cross-Link Guidance
When this page is cited elsewhere, use wording such as:
- "mitochondrial iron-import dysregulation",
- "mitoferrin/Mrs3-Mrs4 axis",
- "iron-driven mitochondrial oxidative injury".
That language is more evidence-faithful than asserting a fully resolved human single-gene `TIC1` driver.
See Also
- [Iron Metabolism](/mechanisms/iron-metabolism)
- [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction)
- [Ferroptosis in Neurodegeneration](/mechanisms/ferroptosis-neurodegeneration)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
External Links
- [NCBI Gene: SLC25A37 (Mitoferrin-1)](https://www.ncbi.nlm.nih.gov/gene/51312)
- [NCBI Gene: SLC25A28 (Mitoferrin-2)](https://www.ncbi.nlm.nih.gov/gene/78984)
References
[Mühlenhoff U, Stadler JA, Richhardt N, et al, A specific role of the yeast mitochondrial carriers Mrs3/4p in mitochondrial iron acquisition under iron-limiting conditions (2003)](https://pubmed.ncbi.nlm.nih.gov/11875579/)
[Shaw GC, Cope JJ, Li L, et al, Mitoferrin is essential for erythroid iron assimilation (2006)](https://pubmed.ncbi.nlm.nih.gov/16778144/)
[Paradkar PN, Zumbrennen KB, Paw BH, Ward DM, Kaplan J, Regulation of mitochondrial iron import through differential turnover of mitoferrin 1 and mitoferrin 2 (2009)](https://pubmed.ncbi.nlm.nih.gov/19001210/)
[Stockwell BR, Friedmann Angeli JP, Bayir H, et al, Ferroptosis: a regulated cell death nexus linking metabolism, redox biology, and disease (2017)](https://pubmed.ncbi.nlm.nih.gov/26774746/)
[Belaidi AA, Bush AI, Iron neurochemistry in Alzheimer's disease and Parkinson's disease: targets for therapeutics (2016)](https://pubmed.ncbi.nlm.nih.gov/29551683/)
[Rouault TA, Mitochondrial iron overload: causes and consequences (2016)](https://pubmed.ncbi.nlm.nih.gov/23906760/)
[Dexter DT, Wells FR, Lee AJ, et al, Increased nigral iron content and alterations in other metal ions occurring in brain in Parkinson's disease (1989)](https://pubmed.ncbi.nlm.nih.gov/1910533/)
[Ward RJ, Zucca FA, Duyn JH, Crichton RR, Zecca L, The role of iron in brain ageing and neurodegenerative disorders (2014)](https://pubmed.ncbi.nlm.nih.gov/26821441/)
[Raven EP, Lu PH, Tishler TA, Heydari P, Bartzokis G, Increased iron levels and decreased tissue integrity in hippocampus of Alzheimer's disease detected in vivo with MRI (2013)](https://pubmed.ncbi.nlm.nih.gov/20668185/)
[Pandolfo M, Hausmann L, Deferiprone for the treatment of Friedreich's ataxia (2013)](https://pubmed.ncbi.nlm.nih.gov/26564095/)
[Do Van B, Gouel F, Jonneaux A, et al, Ferroptosis, a newly characterized form of cell death in Parkinson's disease that is regulated by PKC (2016)](https://pubmed.ncbi.nlm.nih.gov/25258244/)
[Devos D, Moreau C, Devedjian JC, et al, Targeting chelatable iron as a therapeutic modality in Parkinson's disease (2014)](https://pubmed.ncbi.nlm.nih.gov/23548954/)