Atrophin1 is a protein that atn1 is a transcriptional co-regulator with important functions in development and neuronal homeostasis:. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
| Protein Name | Atrophin1 (ATN1) |
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| Gene | [ATN1](/genes/atn1) |
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| UniProt ID | O75718 |
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| PDB Structure | Not determined |
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| Molecular Weight | ~163 kDa |
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| Subcellular Localization | Nucleus, cytoplasm |
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| Protein Family | Atrophin family |
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Atrophin1 (ATN1) is a large protein (~1430 amino acids) containing multiple functional domains:
- Polyglutamine Tract: N-terminal region contains a variable polyglutamine (polyQ) tract that is expanded in disease
- PPM1 Domains: Multiple protein phosphatase-like domains throughout the sequence
- NLS and NES: Nuclear localization and export signals for nucleocytoplasmic shuttling
- Transactivation Domain: C-terminal region involved in transcriptional activation
ATN1 is a transcriptional co-regulator with important functions in development and neuronal homeostasis:
- Transcriptional Regulation: Acts as a transcriptional co-repressor, interacting with histone deacetylases and other chromatin modifiers
- Development: Essential for embryonic development, particularly of the nervous system
- Neuronal Survival: Regulates genes involved in neuronal survival and synaptic plasticity
- Wnt Signaling: Modulates Wnt/β-catenin signaling pathways
ATN1 causes DRPLA when the polyQ tract is expanded:
- Anticipation: Repeat expansion increases across generations, leading to earlier onset
- Clinical Features: Cerebellar ataxia, myoclonus, epilepsy, dementia, and choreoathetosis
- Neuropathology: Neuronal loss in the dentate nucleus, red nucleus, and pallidum
- Molecular Mechanism: Expanded polyQ causes toxic gain-of-function, leading to transcriptional dysregulation and neuronal death
- Aggregation: Mutant ATN1 forms insoluble aggregates in affected neurons
- Huntington's Disease: ATN1 interacts with mutant huntingtin and may modify disease severity
- Spinocerebellar Ataxias: Shared pathogenic mechanisms with other polyQ diseases
Current therapeutic approaches include:
- HTT Reduction: Strategies to reduce mutant ATN1 expression using antisense oligonucleotides
- Transcriptional Modulation: HDAC inhibitors to reverse transcriptional dysregulation
- Aggregation Inhibitors: Small molecules to prevent or disassemble protein aggregates
- Gene Therapy: Viral vector delivery of therapeutic genes
- ATN1 mutations cause DRPLA (1994)
- Polyglutamine expansion in ATN1 (1995)
- ATN1 transcriptional repression (2003)
- ATN1 aggregates in DRPLA (2006)
- Therapeutic strategies for polyQ diseases (2020)