Proteins Containing Expanded Polyglutamine Tracts and Neurodegenerative Disease

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Hereditary neurological and neuromuscular diseases are linked to abnormal trinucleotide repeat expansions.
• Ten polyglutamine (polyQ) diseases involve CAG repeat expansions encoding glutamine.
• CAG repeat length correlates with disease onset and severity in polyQ disorders.

Purpose of the Study:

• To review the aggregation mechanisms of proteins with expanded polyQ-tracts.
• To discuss the structural consequences of polyQ expansion.
• To explore the impact of protein context, post-translational modifications, and lipid membranes on aggregation.

Main Methods:

• Literature review of polyglutamine (polyQ) diseases.
• Analysis of protein aggregation mechanisms.
• Examination of structural changes from monomers to fibrillar aggregates.

Main Results:

• Expanded polyQ tracts promote protein self-assembly into aggregates and inclusion bodies.
• Aggregation is influenced by protein context, post-translational modifications, and potentially lipid membranes.
• Pathogenic mechanisms include gain of toxic function and loss of normal protein function.

Conclusions:

• Understanding polyQ aggregation is crucial for polyglutamine disease pathogenesis.
• Further research into aggregation modifiers may reveal therapeutic targets.
• The interplay between protein structure, function, and aggregation underlies disease progression.