Prions are infectious proteins that result from the structural conversion of proteins into a self-templating conformation. In yeast, a number of glutamine/asparagine-rich proteins have been shown to undergo prion conversions from a soluble form to an insoluble amyloid form. A variety of evidence suggests that these prions may act as epigenetic regulatory elements. Interestingly, numerous human proteins also contain prion-like domains (PrLDs) - domains with compositional similarity to the yeast prion-forming domains. Six of these have recently been linked to various age-related degenerative disorders, heightening the interest in PrLDs. More than 200 other human proteins contain PrLDs, suggesting that aggregation of these proteins may be involved in other diseases. However, despite the importance of these domains in human disease, the sequence basis for their aggregation and toxicity is still poorly understood. Preliminary attempts to define the sequence basis for aggregation of PrLDs recently resulted in the development of PAPA (Prion Aggregation Prediction Algorithm), the first algorithm demonstrated to be able to distinguish between proteins with and without prion-like activity. This proposal builds on these early successes, using a combination of yeast and Drosophila genetics, in vitro experiments, and bioinformatics to rigorously define how the amino acid sequence of PrLDs contributes to aggregation and toxicity.
In Specific Aim 1, a newly developed assay will be employed to quantitatively determine the compositional requirements for aggregation and toxicity of PrLDs.
In Specific Aim 2, a combination of in vitro assays and Drosophila experiments will be used to explore how the propensity to convert to oligomeric and amyloid species affects toxicity in vivo. Finally, in Specific Aim 3, sophisticated bioinformatics methods will be used to incorporate this information into improved prediction algorithms, allowing for the identification of candidate disease-associated or regulatory PrLDs.

Public Health Relevance

In the past few years, a number of previously unexplained degenerative diseases, including some forms of dementia, have been linked to mutations in proteins containing prion-like domains. These mutations cause the proteins to accumulate in cytoplasmic aggregates. Understanding the basis for this aggregation, as well as how these mutations cause toxicity, will potentially aid in the treatment of these terrible diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM105991-05
Application #
9312840
Study Section
Membrane Biology and Protein Processing Study Section (MBPP)
Program Officer
Wehrle, Janna P
Project Start
2013-07-01
Project End
2019-06-30
Budget Start
2017-07-01
Budget End
2019-06-30
Support Year
5
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Colorado State University-Fort Collins
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
785979618
City
Fort Collins
State
CO
Country
United States
Zip Code
80523
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Cascarina, Sean M; Paul, Kacy R; Ross, Eric D (2017) Manipulating the aggregation activity of human prion-like proteins. Prion 11:323-331
Paul, Kacy R; Molliex, Amandine; Cascarina, Sean et al. (2017) Effects of Mutations on the Aggregation Propensity of the Human Prion-Like Protein hnRNPA2B1. Mol Cell Biol 37:
Afsar Minhas, Fayyaz Ul Amir; Ross, Eric D; Ben-Hur, Asa (2017) Amino acid composition predicts prion activity. PLoS Comput Biol 13:e1005465
Li, Songqing; Zhang, Peipei; Freibaum, Brian D et al. (2016) Genetic interaction of hnRNPA2B1 and DNAJB6 in a Drosophila model of multisystem proteinopathy. Hum Mol Genet 25:936-50
Paul, Kacy R; Hendrich, Connor G; Waechter, Aubrey et al. (2015) Generating new prions by targeted mutation or segment duplication. Proc Natl Acad Sci U S A 112:8584-9
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MacLea, Kyle S; Paul, Kacy R; Ben-Musa, Zobaida et al. (2015) Distinct amino acid compositional requirements for formation and maintenance of the [PSI?] prion in yeast. Mol Cell Biol 35:899-911
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