Ataxin-1 fusion partners alter polyQ lethality and aggregation

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Intranuclear inclusion bodies (IBs) are key markers for protein folding diseases.
• Previous research focused on intervening in polyglutamine (polyQ) aggregation to reduce cytotoxicity.
• Emerging evidence suggests polyQ aggregation and cytotoxicity are not always directly linked.

Purpose of the Study:

• To investigate if altering the protein context of pathogenic polyQ proteins can modify their aggregation and cytotoxicity.
• To explore the hypothesis that accelerating IB formation may reduce cellular toxicity.

Main Methods:

• Fused pathogenic ataxin-1 with fluorescent tags (GFP and DsRed1-E5) with differing oligomeric states.
• Utilized spectral properties of DsRed1-E5-ataxin-1 to correlate fluorochrome maturation with cytotoxicity.
• Performed flow cytometry to analyze cell death in transfectants.

Main Results:

• Fusion proteins exhibited distinct cytotoxicity and inclusion body (IB) morphology.
• DsRed1-E5-ataxin-1 fusion showed higher toxicity (31.8% cell death) than GFP-ataxin-1 (12.85%).
• Co-transfection with GFP fusion reduced DsRed1-E5 maturation and toxicity.

Conclusions:

• Fusion partners significantly influence polyglutamine (polyQ) driven aggregation and resulting toxic properties.
• Modifying protein context offers a novel approach to studying inclusion body (IB) aggregation, maturation, and lethality.
• This strategy provides new avenues for understanding and potentially treating protein folding diseases.