Ataxin 1

1OA8, 4APT, 4AQP, 4J2J, 4J2L, 2M41631020238ENSG00000124788ENSMUSG00000046876P54253P54254NM_001128164NM_000332NM_001357857NM_001199304NM_001199305NM_009124NP_000323NP_001121636NP_001344786NP_001186233NP_001186234NP_033150Ataxin-1 is a DNA-binding protein which in humans is encoded by the ATXN1 gene. Ataxin-1 is a DNA-binding protein which in humans is encoded by the ATXN1 gene. Mutations in ataxin-1 cause spinocerebellar ataxia type 1, an inherited neurodegenerative disease characterized by a progressive loss of cerebellar neurons, particularly Purkinje neurons. ATXN1 is conserved across multiple species, including humans, mice, and Drosophila. In humans, ATXN1 is located on the short arm of chromosome 6. The gene contains 9 exons, two of which are protein-coding. There is a CAG repeat in the coding sequence which is longer in humans than other species (6-38 uninterrupted CAG repeats in healthy humans versus 2 in the mouse gene). This repeat is prone to errors in DNA replication and can vary widely in length between individuals. Notable features of the Ataxin-1 protein structure include: The function of Ataxin-1 is not completely understood. It appears to be involved in regulating gene expression based on its location in the nucleus of the cell, its association with promoter regions of several genes, and its interactions with transcriptional regulators and parts of the RNA splicing machinery. Ataxin 1 has been shown to interact with: ATXN1 is the gene mutated in spinocerebellar ataxia type 1 (SCA1), a dominantly-inherited, fatal genetic disease in which neurons in the cerebellum and brain stem degenerate over the course of years or decades. SCA1 is a trinucleotide repeat disorder caused by expansion of the CAG repeat in ATXN1; this leads to an expanded polyglutamine tract in the protein. This elongation is variable in length, with as few as 6 and as many as 81 repeats reported in humans. Repeats of 39 or more uninterrupted CAG triplets cause disease, and longer repeat tracts are correlated with earlier age of onset and faster progression.