Faculty Sponsor(s)
Kyle MacLea
Location
Jereld R. Nicholson Library
Subject Area
Biochemistry
Description
The formation of prions in the baker’s yeast Saccharomyces cerevisiae is determined by amino acid composition rather than the primary sequence of amino acids. The infectious amyloid proteins known as prions undergo nucleation and propagation, two distinct activities critical for prion formation. The ability for prions to be transferred from cell to cell, or propagate, is of interest not only in yeast prions but also in prion diseases such as the mammalian spongiform encephalopathies. Prion formation has been widely studied in yeast prions, however, the fundamental mechanisms behind the specific process of propagation of prions from cell to cell are not yet understood. In the most well-studied yeast prion, the prion form [PSI+] of Sup35, a domain of 5 ½ degenerate oligopeptide repeats called the oligopeptide repeat domain (ORD) has been shown to be important for prion propagation and to have a distinct amino acid composition as compared to the nucleation domain region. A library mutagenesis experiment has identified amino acids that favor or disfavor prion propagation in yeast cells. To confirm the results of the random library mutagenesis experiment, we generated several clones in which a portion of the ORD (the fourth oligopeptide repeat) was replaced with defined sequences expected to propagate or fail to propagate.
Recommended Citation
Knox, James D. and Davis, Emily, "Targeted Mutagenesis of the Oligopeptide Repeat Domain of the Yeast Prion Sup35" (2014). Linfield University Student Symposium: A Celebration of Scholarship and Creative Achievement. Event. Submission 37.
https://digitalcommons.linfield.edu/symposium/2014/all/37
Targeted Mutagenesis of the Oligopeptide Repeat Domain of the Yeast Prion Sup35
Jereld R. Nicholson Library
The formation of prions in the baker’s yeast Saccharomyces cerevisiae is determined by amino acid composition rather than the primary sequence of amino acids. The infectious amyloid proteins known as prions undergo nucleation and propagation, two distinct activities critical for prion formation. The ability for prions to be transferred from cell to cell, or propagate, is of interest not only in yeast prions but also in prion diseases such as the mammalian spongiform encephalopathies. Prion formation has been widely studied in yeast prions, however, the fundamental mechanisms behind the specific process of propagation of prions from cell to cell are not yet understood. In the most well-studied yeast prion, the prion form [PSI+] of Sup35, a domain of 5 ½ degenerate oligopeptide repeats called the oligopeptide repeat domain (ORD) has been shown to be important for prion propagation and to have a distinct amino acid composition as compared to the nucleation domain region. A library mutagenesis experiment has identified amino acids that favor or disfavor prion propagation in yeast cells. To confirm the results of the random library mutagenesis experiment, we generated several clones in which a portion of the ORD (the fourth oligopeptide repeat) was replaced with defined sequences expected to propagate or fail to propagate.
