Truncated PrPc in mammalian brain: interspecies variation and location in membrane rafts

A key molecular event in prion diseases is the conversion of cellular prion protein (PrPc) into an abnormal misfolded conformer (PrPsc). The PrPc N-terminal domain plays a central role in PrPc functions and in prion propagation. Because mammalian PrPc is found as a full-length and N-terminally truncated form, we examined the presence and amount of PrPc C-terminal fragment in the brain of different species. We found important variations between primates and rodents. In addition, our data show that the PrPc fragment is present in detergent-resistant raft domains, a membrane domain of critical importance for PrPc functions and its conversion into PrPsc.