Ataxin-3 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ''ATXN3''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Clinical significance
Machado–Joseph disease
Machado–Joseph disease (MJD), also known as Machado–Joseph Azorean disease, Machado's disease, Joseph's disease or spinocerebellar ataxia type 3 (SCA3), is a rare autosomal dominantly inherited neurodegenerative disease that causes progressi ...
, also known as spinocerebellar ataxia-3, is an
autosomal dominant
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...
neurologic disorder. The protein encoded by the ''ATXN3'' gene contains
CAG repeats in the coding region, and the expansion of these repeats from the normal 13-36 to 68-79 is the cause of Machado–Joseph disease. This disorder is thus a
trinucleotide repeat disorder
In genetics, trinucleotide repeat disorders, a subset of microsatellite expansion diseases (also known as repeat expansion disorders), are a set of over 30 genetic disorders caused by trinucleotide repeat expansion, a kind of mutation in which ...
type I known as a
polyglutamine (PolyQ) disease. There is an inverse correlation between the age of onset and CAG repeat numbers. Alternatively spliced transcript variants encoding different isoforms have been described for this gene.
Interactions
Ataxin 3 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization advocating for the legal and human rights of children with intersex traits. The organization was founded in 2006 and fo ...
with:
*
RAD23A
UV excision repair protein RAD23 homolog A is a protein that in humans is encoded by the ''RAD23A'' gene.
Function
The protein encoded by this gene is one of two human homologs of ''Saccharomyces cerevisiae'' Rad23, a protein involved in nucle ...
,
*
RAD23B
UV excision repair protein RAD23 homolog B is a protein that in humans is encoded by the ''RAD23B'' gene.
Function
The protein encoded by this gene is one of two human homologs of Saccharomyces cerevisiae Rad23, a protein involved in nucleoti ...
,
[ and
* VCP.]
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Spinocerebellar Ataxia Type 3
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{{Posttranslational modification
Proteins