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Exploring the basis of [PIN(+)] variant differences in [PSI(+)] induction.
1Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
Journal of Molecular Biology
|June 18, 2013
Summary
The prion [PIN(+)] enhances the formation of the prion [PSI(+)] in yeast. Different [PIN(+)] variants influence [PSI(+)] formation differently, suggesting variations in prion seed quality rather than quantity.
Area of Science:
- Molecular Biology
- Yeast Genetics
- Prion Biology
Background:
- Soluble proteins can form self-templating amyloid aggregates known as prions.
- Prion variants arise from the same protein but exhibit distinct heritable properties.
- [PSI(+)] (Sup35 prion) and [PIN(+)] (Rnq1 prion) are key yeast prions.
Purpose of the Study:
- To investigate the mechanism by which [PIN(+)] variants differentially enhance de novo [PSI(+)] induction.
- To explore the role of heterologous prion cross-seeding in prion variant specificity.
Main Methods:
- Yeast genetics to study prion induction and propagation.
- Co-immunoprecipitation to assess protein interactions.
- Analysis of prion variant characteristics and seed transmission.
Main Results:
- Different [PIN(+)] variants showed preferential promotion of specific [PSI(+)] variants, supporting cross-seeding.
- This specificity was not observed in in vitro experiments.
- [PIN(+)] variant efficiency did not correlate with Rnq1 co-immunocapture levels or propagons number.
Conclusions:
- The findings suggest that [PIN(+)] variants influence [PSI(+)] induction through the quality of their cross-seeding seeds, not just the quantity.
- Prion variant specificity may depend on post-binding interactions between heterologous prion seeds and substrates.
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