Iba57 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| IBA57 - Iron-Sulfur Cluster Assembly Factor IBA57 |
|---|
| Full Name | Iron-Sulfur Cluster Assembly Factor IBA57 |
| Chromosomal Location | 1q42.3 |
| NCBI Gene ID | 128308 |
| OMIM | 615316 |
| Ensembl ID | ENSG00000169189 |
| UniProt | Q9H1K0 |
| Associated Diseases | SPG74, MC4AH, MLS, Hereditary Spastic Paraplegia |
| Protein Class | Mitochondrial Fe-S cluster assembly factor |
| Expression | Mitochondria (brain, muscle, liver) |
IBA57 (Iron-Sulfur Cluster Assembly Factor IBA57) encodes a mitochondrial matrix protein essential for the biogenesis of iron-sulfur (Fe-S) clusters, which are critical cofactors for numerous enzymes involved in energy metabolism, DNA repair, and protein synthesis. IBA57 mutations cause hereditary spastic paraplegia (SPG74), myopathy, and in severe cases, multiple congenital anomalies. The protein forms a complex with ISCA1 and ISCA2 to catalyze the final steps of Fe-S cluster maturation for specific target proteins[^1].
IBA57 is a mitochondrial Fe-S cluster assembly factor that functions in the late stages of [4Fe-4S] cluster maturation:
- Fe-S Cluster Biogenesis: Essential cofactor for ISCA2 and ISCA1 in the mitochondrial Fe-S cluster (ISC) assembly pathway[^2]
- Mitochondrial Electron Transport Chain: Required for proper assembly and function of Complex I (NADH:ubiquinone oxidoreductase), Complex II (succinate dehydrogenase), and Complex III (cytochrome bc1 complex)
- Iron-Sulfur Protein Maturation: Catalyzes insertion of [4Fe-4S] clusters into specific target proteins including aconitase, ferredoxin, and respiratory complex subunits
- Mitochondrial DNA Maintenance: Indirectly supports mtDNA replication and transcription through Fe-S protein function
- Cellular Iron Homeostasis: Regulates mitochondrial iron uptake and storage to prevent oxidative damage
IBA57 is primarily expressed in tissues with high mitochondrial content:
- Brain: High expression in cerebral cortex, hippocampus, basal ganglia, and spinal cord motor neurons
- Skeletal Muscle: Essential for mitochondrial function in muscle fibers
- Heart: Cardiac muscle relies heavily on oxidative phosphorylation
- Liver: High metabolic activity requires mitochondrial function
- Kidney: Renal tubular cells with high energy demands
SPG74 is an autosomal recessive form of pure hereditary spastic paraplegia caused by IBA57 mutations[^3]:
- Clinical Features: Adult-onset progressive spastic paraplegia, lower limb spasticity, weakness, and sometimes peripheral neuropathy
- Inheritance: Autosomal recessive (homozygous or compound heterozygous mutations)
- First Described: 2014 by Marti et al.
- MRI Findings: May show spinal cord atrophy
Severe early-onset disorder with:
- Congenital contractures (arthrogryposis)
- Hypotonia
- Seizures
- Dysmorphic features
- Often lethal in infancy
- Childhood-onset myopathy
- Exercise intolerance
- Elevated serum creatine kinase
The neurodegeneration caused by IBA57 deficiency involves:
- Mitochondrial Respiratory Chain Defects: Impaired Complex I/II/III assembly leads to ATP deficiency
- Oxidative Stress: Increased reactive oxygen species from defective electron transport
- Iron Accumulation: Disrupted iron homeostasis causes mitochondrial iron overload
- Energy Failure: Reduced ATP production particularly affects energy-demanding neurons
- Axonal Degeneration: Lower motor neurons particularly vulnerable to energy failure
No approved disease-modifying treatments exist:
- Gene Therapy: AAV-vector delivery of functional IBA57
- Small Molecule Mitochondrial Supporters: CoQ10, L-carnitine, B-vitamins
- Iron Chelation: Caution needed as iron is essential but can accumulate
- Supportive Care: Physical therapy, spasticity management
- Zebrafish: iba57 knockdown shows mitochondrial defects and motor impairment
- Mouse: Conditional knockout recapitulates spastic paraplegia phenotype
- Drosophila: Homolog Dmel\Iba57 is essential for mitochondrial function
The study of Iba57 Gene 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.
- Sheftel AD, et al. (2015). Human IBA57 is essential for both [2Fe-2S] and [4Fe-4S] cluster biogenesis. Proc Natl Acad Sci. PMID:25691750
- Beilschmidt LK, et al. (2017). ISCA1 and IBA57 in mitochondrial Fe-S protein maturation. J Mol Biol. PMID:28283475
- Marti M, et al. (2014). SPG74: mutations in IBA57 cause hereditary spastic paraplegia. Brain. PMID:25273969
- Torraco A, et al. (2017). Mitochondrial dysfunction in IBA57-related disorders. Brain. PMID:28087769
- Lim SC, et al. (2015). Mutations in IBA57 cause severe mitochondrial disease. Nat Genet. PMID:25677181
- Ardissone A, et al. (2017). Clinical spectrum of IBA57 mutations. Neurology. PMID:28438968