Related Experiment Video
Updated: Mar 8, 2026
Screening for Amyloid Aggregation by Semi-Denaturing Detergent-Agarose Gel Electrophoresis
Published on: July 16, 2008
Effects of Mutations on the Aggregation Propensity of the Human Prion-Like Protein hnRNPA2B1
Kacy R Paul1, Amandine Molliex2, Sean Cascarina1
1Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, Colorado, USA.
Abstract:
Hundreds of human proteins contain prion-like domains, which are a subset of low-complexity domains with high amino acid compositional similarity to yeast prion domains. A recently characterized mutation in the prion-like domain of the human heterogeneous nuclear ribonucleoprotein hnRNPA2B1 increases the aggregation propensity of the protein and causes multisystem proteinopathy. The mutant protein forms cytoplasmic inclusions when expressed in Drosophila, the mutation accelerates aggregation in vitro, and the mutant prion-like domain can substitute for a portion of a yeast prion domain in supporting prion activity. To examine the relationship between amino acid sequence and aggregation propensity, we made a diverse set of point mutations in the hnRNPA2B1 prion-like domain. We found that the effects on prion formation in Saccharomyces cerevisiae and aggregation in vitro could be predicted entirely based on amino acid composition. However, composition was an imperfect predictor of inclusion formation in Drosophila; while most mutations showed similar behaviors in yeast, in vitro, and in Drosophila, a few showed anomalous behavior. Collectively, these results demonstrate the significant progress that has been made in predicting the effects of mutations on intrinsic aggregation propensity while also highlighting the challenges of predicting the effects of mutations in more complex organisms.
Insights
Mutations in human prion-like domains can be predicted to affect protein aggregation based on amino acid composition. However, predicting effects in complex organisms like Drosophila remains challenging.
Area of Science:
- Biochemistry
- Molecular Biology
- Genetics
Background:
- Hundreds of human proteins feature prion-like domains (PLDs), which are low-complexity domains sharing compositional similarity with yeast prion domains.
- A mutation in the PLD of human hnRNPA2B1 protein increases aggregation and causes multisystem proteinopathy, forming inclusions in Drosophila and accelerating aggregation in vitro.
Purpose of the Study:
- To investigate the relationship between amino acid sequence and protein aggregation propensity.
- To determine if amino acid composition can predict the effects of mutations on prion-like domain behavior across different model systems.
Main Methods:
- Created diverse point mutations within the hnRNPA2B1 prion-like domain.
- Assessed prion formation in Saccharomyces cerevisiae.
- Measured protein aggregation in vitro.
- Observed inclusion formation in Drosophila.
Main Results:
- Amino acid composition accurately predicted prion formation in yeast and aggregation in vitro.
- Composition was an imperfect predictor for inclusion formation in Drosophila.
- Most mutations exhibited consistent behavior across yeast, in vitro, and Drosophila models, with a few exceptions.
Conclusions:
- Significant progress has been made in predicting the intrinsic aggregation propensity of mutations based on amino acid composition.
- Predicting the impact of mutations on protein aggregation in complex organisms presents ongoing challenges.
Related Concept Videos
03:03Amyloid Fibrils
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
01:39Mutations