Abstract
Prions are self-perpetuating, alternative protein conformations associated with neurological diseases and normal cellular functions. Saccharomyces cerevisiae contains many endogenous prions, providing a powerful system to study prionization. Previously, we demonstrated that Swi1, a component of the SWI/SNF chromatin-remodeling complex, can form the prion [SWI1]. A small region, Swi11–38, with a unique amino acid composition of low complexity, acts as a prion domain and supports [SWI1] propagation. Here, we further examine Swi11–38 through site-directed mutagenesis. We found that mutations of the two phenylalanine residues or the threonine tract inhibit Swi11–38 aggregation. In addition, mutating both phenylalanines can abolish de novo prion formation by Swi11–38, whereas mutating only one phenylalanine does not. Replacement of half of or the entire eight-threonine tract with alanines has the same effect, possibly disrupting a core region of Swi11–38 aggregates. We also show that Swi11–38 and its prion-fold-maintaining mutants form high-molecular-weight, SDS-resistant aggregates, whereas the double-phenylalanine mutants eliminate these protein species. These results indicate the necessity of the large hydrophobic residues and threonine tract in Swi11–38 in prionogenesis, possibly acting as important aggregable regions. Our findings thus highlight the importance of specific amino acid residues in the Swi1 prion domain in prion formation and maintenance.
Original language | English (US) |
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Article number | e00044-21 |
Journal | Molecular and cellular biology |
Volume | 41 |
Issue number | 7 |
DOIs | |
State | Published - Jun 2021 |
Funding
We thank J. S. Weissman (University of California, San Francisco) for the W303 sup35D/p316SUP35FL yeast strain. This work was supported by grants from the National Institutes of Health (R01GM110045) to L.L. and from the National Institutes of Health (R01GM126318) to Z.D. The funders had no role in the study design, data collection and interpretation, or decision to submit the work for publication.
Keywords
- Prion domain
- Prionogenesis
- Protein aggregation
- SWI
- SWI/SNF
- Saccharomyces cerevisiae
- Swi1
- Yeast
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology