Neurotoxic species in prion disease: a role for PrP isoforms?

Prion diseases such as bovine spongiform encephalopathy in cattle and Creutzfeldt-Jakob disease in humans are associated with the misfolding and accumulation of an abnormal conformation of the host-encoded prion protein (PrP). Despite intensive research efforts conducted on PrP, the toxic agent involved in neurodegeneration is as yet unidentified. Several potential candidates have been proposed, each of which may be relevant to subsets of the broad array of prion diseases. In this study, we review current knowledge on neurotoxic PrP species, including the importance of a central hydrophobic domain for mediating neurotoxicty.