Pur-alpha functionally interacts with FUS carrying ALS-associated mutations.

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron loss.
• Mutations in the Fused in Sarcoma (FUS) protein are linked to ALS, causing it to aggregate in stress granules.

Purpose of the Study:

• To investigate the role of Pur-alpha protein in the pathogenesis of FUS-associated ALS.
• To explore the link between Pur-alpha, FUS aggregation, and protein synthesis dysregulation in ALS.

Main Methods:

• Studied the interaction between Pur-alpha and mutated FUS in patient-derived motoneuronal cells.
• Analyzed the effect of Pur-alpha and FUS on protein synthesis initiation factor eIF2alpha phosphorylation.
• Utilized Drosophila models to assess the in vivo impact of Pur-alpha on FUS-induced neurodegeneration and motor function.

Main Results:

• Pur-alpha physically interacts with mutated FUS in an RNA-dependent manner and colocalizes in stress granules.
• Both Pur-alpha and mutated FUS upregulate eIF2alpha phosphorylation, inhibiting global protein synthesis.
• Overexpression of Pur-alpha worsens FUS-induced neurodegeneration in Drosophila, while its downregulation improves motor function.

Conclusions:

• Pur-alpha plays a significant role in the pathogenesis of FUS-associated ALS, likely through the regulation of mRNA translation.
• Altered protein synthesis is implicated in ALS, with Pur-alpha emerging as a key factor in motoneuronal dysfunction.