ROLE OF THE CHAPERONE PROTEIN HSP104 IN PROPAGATION OF THE YEAST PRION-LIKE FACTOR [PSI(+)]

The yeast non-Mendelian factor [psi(+)] has been suggested to be a sel f-modified protein analogous to mammalian prions. Here it is reported that an intermediate amount of the chaperone protein Hsp104 was requir ed for the propagation of the [psi(+)] factor. Overproduction or inact ivation of Hsp104 caused the loss of [psi(+)]. These results suggest t hat chaperone proteins play a role in prion-like phenomena, and that a certain level of chaperone expression can cure cells of prions withou t affecting viability. This may lead to antiprion treatments that invo lve the alteration of chaperone amounts or activity.