ALS Mutations Shift the Isoelectric Point of the KIF5A C Terminal Inducing Protein Aggregation and TDP-43...

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neurons.
• Genetic mutations, including in KIF5A, are linked to ALS pathogenesis.
• KIF5A mutations disrupt protein transport and are associated with motor neuron diseases.

Purpose of the Study:

• Investigate the impact of ALS-related KIF5A mutations on motor neuron pathology.
• Determine the role of KIF5A protein aggregation and TDP-43 mislocalization in ALS.
• Explore therapeutic strategies by modifying KIF5A properties.

Main Methods:

• Utilized cell culture models of human motoneurons.
• Overexpressed wild-type and mutant KIF5A proteins.
• Analyzed protein aggregation and TDP-43 localization.
• Engineered a KIF5A variant with altered isoelectric point (pI).

Main Results:

• ALS-related KIF5A mutations cause mutant protein accumulation in motoneurons.
• Mutant KIF5A exacerbates TDP-43 mislocalization, a key ALS hallmark.
• Modifying the isoelectric point (pI) of the KIF5A C-terminal domain reduced protein aggregation and TDP-43 mislocalization.

Conclusions:

• KIF5A mutations contribute to ALS pathology through protein aggregation and TDP-43 mislocalization.
• The altered isoelectric point of mutant KIF5A is a critical factor in its toxicity.
• Restoring a neutral pI represents a potential therapeutic avenue for KIF5A-linked ALS.