ABSTRACT
The infectivity of transmissible spongiform encephalopathies (TSEs) was explained by the prion hypothesis proposing that the inheritance of biological information can be achieved by self-propagating conformational changes in the prion protein PrP [1]. The prion list has since been extended to include protein-based genetic elements found in fungi [2]. The beststudied yeast prions [PSI+], [PIN+] (often called [RNQ+]) and [URE3] are, respectively, self-propagating conformations of: Sup35, a translation termination factor; Rnq1, a protein of unknown function; and Ure2, a nitrogen catabolism repression regulator [3]–[5]. Other recently discovered yeast prions include [SWI+], [OCT+], [ISP+], [MOT3+] and [MOD5] [6], [7]. The propagation of most [8]–[10], but not all [6] yeast prions is driven by their Q/N-rich prion domains that have the propensity to form aggregates
in vivo and assemble into self-seeding, β-sheet-rich amyloid fibers in vitro 11,12.
