ABSTRACT
Prions are proteins that propagate phenotypic traits through self-perpetuating folding events. The nature of the conformational change that conveys the functional constitutive form of a prion protein to a form with persistent altered function and the ability to convert constitutive prion molecules into modified prions is poorly understood. We present here what is known about the assembly into protein fibrils of four yeast prions in test tubes. We also describe how molecular chaperones modulate the assembly of yeast prions in vitro and through their assembly, promoting and sequestering activities, tune the propagation of prions phenotypic traits from mother to daughter cells. Finally the notion of prion “infectivity” is discussed in a cellular context and from a structural perspective.
