Anti-Ataxin-3 / ATXN3 / ATX3 R

Ataxin-3 is a protein encoded by the ATXN3 gene, primarily expressed in the brain, particularly in regions involved in motor coordination, such as the cerebellum. Ataxin-3 belongs to the Joubert syndrome protein family and is characterized by its Josephin domain, which exhibits deubiquitinase activity, meaning it can remove ubiquitin molecules from proteins. This function is important for regulating the stability and activity of various cellular proteins. Ataxin-3 is best known for its association with Spinocerebellar Ataxia Type 3 (SCA3), also known as Machado-Joseph disease, a neurodegenerative disorder. In this condition, an expansion of a CAG trinucleotide repeat in the ATXN3 gene results in the production of an abnormally long polyglutamine tract, leading to protein misfolding, aggregation, and neuronal toxicity. The dysfunction of Ataxin-3 is linked to the progressive loss of coordination, balance, and motor control seen in SCA3. Beyond its role in neurodegeneration, research is exploring its involvement in other cellular processes, including gene expression regulation, protein degradation, and cell signaling.