ABSTRACT
Perhaps the most exciting research for the coming years will be focused on determining whether the prion phenomenon of propagation of biological information is the exclusive province of a limited group of proteins, like the prion protein (PrP), or rather is a more general process in biology. The findings of proteins with a prion-like behavior in yeast and other fungi have provided a step forward in this direction [Lindquist, 1997; Wickner et al., 1999]. Recent findings about the molecular mechanism by which prions replicate and propagate in vivo and in vitro suggest that other proteins forming β-sheet-rich amyloid-like aggregates have the possibility of behaving like prions. Exciting recent studies in other protein misfolding disorders (PMD) have provided good evidence for a potential infectious origin of other diseases of the group. This, coupled with the changing view that amyloids are a more general phenomenon and are not only associated with disease, raises the possibility that the prion phenomenon of propagating changes in protein function by transmission of alternative protein folding will be found to be much more common than we currently think.
