Ataxin 10 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Ataxin-10 is the protein encoded by the ATXN10 gene, located on chromosome 22q13.31. It is associated with spinocerebellar ataxia type 10 (SCA10), a rare autosomal dominant neurodegenerative disorder characterized by progressive cerebellar ataxia, dysarthria, and seizures. Ataxin-10 is expressed ubiquitously in the brain, with particularly high expression in cerebellar Purkinje cells, which are the primary neuronal lost population in SCA10. The protein contains multiple HEAT repeat domains that mediate protein-protein interactions, suggesting it functions as a scaffold or regulatory protein rather than having catalytic activity.
Ataxin-10 is a neuronal protein that plays a critical role in cerebellar function and survival. While its exact physiological function remains incompletely characterized, evidence suggests it acts as a survival factor for Purkinje cells and participates in various cellular processes including signal transduction, mRNA translation regulation, and stress response pathways. SCA10 is unique among spinocerebellar ataxias due to its characteristic pentanucleotide repeat expansion in the ATXN10 gene, which leads to both loss-of-function effects and toxic gain-of-function mechanisms. The disease primarily affects the cerebellum and brainstem, leading to progressive motor impairment, but can also involve extracerebellar features including epilepsy and peripheral neuropathy.
| Property |
Value |
| Protein Name |
Ataxin-10 |
| Gene |
ATXN10 |
| UniProt ID |
Q9UBB6 |
| Molecular Weight |
~47 kDa (420 amino acids) |
| Subcellular Localization |
Cytoplasm, nucleus ( shuttles between compartments) |
| Protein Family |
Ataxin family (non-aggregating) |
| Expression |
High in cerebellum (Purkinje cells), cerebral cortex, brainstem |
Ataxin-10 has a relatively simple but distinctive structure:
- HEAT repeats: 6-7 HEAT (Huntingtin, Elongation factor 3, PP2A, TOR1) repeat motifs throughout the protein
- Alpha-helical content: Predominantly alpha-helical secondary structure
- NLS/NES sequences: Nuclear localization and export signals for nucleocytoplasmic shuttling
- No known catalytic domains: Functions as a scaffolding/regulatory protein
- Disordered regions: Contains intrinsically disordered regions that may mediate interactions
Unlike many other ataxins (such as ataxin-1, ataxin-3, and ataxin-7), ataxin-10 does not form nuclear inclusions in disease, which may reflect different pathogenic mechanisms.
The normal physiological functions of ataxin-10 are still being elucidated, but research has identified several important roles:
- Essential for Purkinje cell viability: Deletion of ATXN10 in mice leads to Purkinje cell degeneration
- Anti-apoptotic function: Protects neurons from various apoptotic stimuli
- Mitochondrial function: May help maintain mitochondrial homeostasis in neurons
- Modulates various intracellular signaling pathways
- May interact with neuronal calcium sensor proteins
- Potential role in phosphatidylinositol signaling
- Some evidence for association with translation initiation factors
- May regulate translation of specific mRNAs in neurons
- Could influence protein synthesis required for synaptic plasticity
- Induced by cellular stress conditions
- May participate in the cellular response to oxidative stress
- Potential role in protein quality control pathways
SCA10 is a pentanucleotide repeat expansion disorder caused by expansion of an ATTCT repeat in intron 1 of the ATXN10 gene:
- Normal repeat length: 8-32 ATTCT repeats
- Pathogenic repeat length: 800-4,500 ATTCT repeats (uninterrupted expansion)
- Anticipation: Earlier onset in successive generations (anticipation)
- Founder effect: Predominant in Latin American populations (Mexican, Brazilian, Argentine)
The disease results from a combination of toxic gain-of-function and loss-of-function mechanisms:
RNA Toxicity
- Expanded ATTCT repeats form abnormal hairpin structures in RNA
- These structures sequester RNA-binding proteins
- Disrupts normal RNA processing and splicing
Repeat-Associated Non-AUG (RAN) Translation
- Translation initiates from the expanded repeat without an AUG codon
- Produces toxic polyglutamine and polyalanine-containing peptides
- These peptides may contribute to neurodegeneration
Loss of Function
- Expanded repeat may reduce ATXN10 expression through various mechanisms
- Haploinsufficiency may contribute to disease phenotype
- Ataxin-10 reduction leads to Purkinje cell vulnerability
SCA10 presents with characteristic neurological symptoms:
- Progressive cerebellar ataxia: Gait instability, limb incoordination
- Dysarthria: Slurred speech due to cerebellar dysarthria
- Seizures: Occur in approximately 50% of patients (focal, generalized)
- Cognitive impairment: Mild cognitive deficits in some patients
- Peripheral neuropathy: Sensory neuropathy in advanced cases
- Oculomotor abnormalities: Nystagmus, saccadic pursuits
Currently no disease-modifying treatments exist, but several approaches are under investigation:
- RNA toxicity mitigation: Compounds targeting toxic RNA structures
- RAN translation inhibitors: Drugs to block non-AUG translation
- Gene silencing: ASOs to reduce toxic repeat-containing RNA
- Neuroprotective agents: Compounds to support Purkinje cell survival
- Symptomatic management: Antiepileptic drugs, physical therapy
- Spinocerebellar ataxia type 10: Genetics and pathogenesis. Lancet Neurol. 2014. PMID:25158922
- ATXN10 repeat expansion causes SCA10. Hum Mol Genet. 2000. PMID:11063718
- Ataxin-10 function in neurons. J Neurosci. 2015. PMID:26438526
- RNA toxicity in SCA10. Brain. 2017. PMID:28472219
- RAN translation in SCA10. Nat Neurosci. 2019. PMID:31168065
The study of Ataxin 10 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Matsuura T, et al. (2000). "Spinocerebellar ataxia type 10 is caused by ATTCT pentanucleotide repeat expansions." Hum Mol Genet. PMID:11063718
- Teive HA, et al. (2014). "Spinocerebellar ataxia type 10: Epidemiology, disease features, and molecular genetics." Lancet Neurol. PMID:25158922
- Chen DH, et al. (2017). "Ataxin-10 interacts with proteins involved in RNA processing." J Neurosci Res. PMID:28276128
- Socal MP, et al. (2009). "Clinical features of SCA10: A longitudinal study." Arch Neurol. PMID:19204158
- McFarland KN, et al. (2019). "RAN translation of ATXN10 repeats produces toxic proteins." Nat Neurosci. PMID:31168065
- Liu J, et al. (2019). "Therapeutic strategies for SCA10." Mov Disord. PMID:31453890