Frataxin

Frataxin is a is_associated_with::protein that in humans is encoded by the FXN is_associated_with::gene.

Frataxin is localized to the is_associated_with::mitochondrion. The function of frataxin is not entirely clear, but it seems to be involved in assembly of is_associated_with::iron-sulfur clusters. It has been proposed to act as either an iron chaperone or an iron storage protein.

Frataxin is_associated_with::mRNA is predominantly expressed in tissues with a high metabolic rate (including liver, kidney, brown fat and heart). Mouse and yeast frataxin homologues contain a potential N-terminal mitochondrial targeting sequence, and human frataxin has been observed to co-localise with a is_associated_with::mitochondrial protein. Furthermore, disruption of the is_associated_with::yeast gene has been shown to result in is_associated_with::mitochondrial dysfunction. is_associated_with::Friedreich's ataxia is thus believed to be a mitochondrial is_associated_with::disease caused by a is_associated_with::mutation in the nuclear genome (specifically, expansion of an intronic GAA triplet repeat in the FXN gene, which encodes the protein frataxin.).

Clinical significance
Reduced expression of frataxin is the cause of is_associated_with::Friedreich's ataxia (FRDA), a lethal neurodegenerative disease. The reduction in frataxin gene expression may be attributable from either the silencing of transcription of the frataxin gene because of epigenetic modifciations in the chromosomal entity or from the inability of splicing the expanded GAA repeats in the first intron of the pre-mRNA as seen in Bacteria and Human cells or both. The expansion of is_associated_with::intronic trinucleotide repeat GAA results in Friedreich's ataxia.

An overexpression of frataxin in is_associated_with::Drosophila has shown an increase in antioxidant capability, resistance to oxidative stress insults and longevity.

Interactions
Frataxin has been shown to biologically interact with the enzyme is_associated_with::PMPCB.