Ataxin-3 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the ''ATXN3''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
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 effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
neurologic disorder. The protein encoded by the ''ATXN3'' gene contains
CAG repeats
Trinucleotide repeat disorders, also known as microsatellite expansion diseases, are a set of over 50 genetic disorders caused by trinucleotide repeat expansion, a kind of mutation in which repeats of three nucleotides ( trinucleotide repeats) inc ...
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
Trinucleotide repeat disorders, also known as microsatellite expansion diseases, are a set of over 50 genetic disorders caused by trinucleotide repeat expansion, a kind of mutation in which repeats of three nucleotides ( trinucleotide repeats) inc ...
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 using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with:
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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 nucl ...
,
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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 nucleotide ...
,
[ and
* VCP.]
Model organisms
Model organism
A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workin ...
s have been used in the study of ATXN3 function. A conditional knockout mouse
A knockout mouse, or knock-out mouse, is a genetically modified mouse (''Mus musculus'') in which researchers have inactivated, or "knocked out", an existing gene by replacing it or disrupting it with an artificial piece of DNA. They are importan ...
line called ''Atxn3tm1a(KOMP)Wtsi'' was generated at the Wellcome Trust Sanger Institute
The Wellcome Sanger Institute, previously known as The Sanger Centre and Wellcome Trust Sanger Institute, is a non-profit British genomics and genetics research institute, primarily funded by the Wellcome Trust.
It is located on the Wellcome G ...
.phenotypic screen
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
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