SIR Medicine Investigation Abstract
AGGREGATION OF POLYGLUTAMINE EXPANSION PROTEIN IN A C. ELEGANS MODEL
Presenter:
Rebecca M. Krock, Illinois Mathematics and Science Academy, 1500 West Sullivan Road, Aurora, IL, 60506
Mentor:
Dr. Richard Morimoto, Northwestern University
Abstract:
Huntington's disease (HD) is characterized by expansions of CAG repeats, which encode the amino acid glutamine. The expansion of glutamine repeats results in the appearance of protein aggregates, or clumps, which is associated with cellular toxicity and disease progression. The disease could be due to either the protein aggregate itself or some other biochemical state that leads to polyglutamine (polyQ) aggregation. Having observed the appearance of visible aggregates in Caenorhabditis elegans, a transparent nematode, I examined changes in the biochemical aspect of polyglutamine protein expression and aggregation in worms of different polyQ-lengths. I first optimized a protocol for extracting proteins from C. elegans, and found that using crushing, freeze/thaw, and the enzyme collagenase in combination was an efficient method of extraction. I then used this procedure to examine the relative amounts of aggregated and soluble (normal) proteins from C. elegans with various polyQ-lengths. Proteins were quantified using protein assays, fluorometry, native gels, dot blots, and Western blots. The comparison of the visual and biochemical aggregation can help us understand protein misfolding and aggregation in vivo.