A cell system to detect newly synthesised prions in the laboratory is reported in this week’s Nature Communications and shows that prion proteins rapidly infect cells. These findings may open new opportunities for investigating the synthesis and pathological role of prion proteins.

Neurodegenerative prion diseases, such as Creutzfeldt-Jakob disease (CJD), are characterised by misfolded prion proteins, however this has been difficult to study in a laboratory setting because the proteins used to inoculate the cell cultures are identical to those that are expressed by the host cell. Sarah Tabrizi and colleagues have developed a new system where a tagged prion protein is introduced into cells in culture. This allows the study of the early features of prion infection. Using this, the team show that, in the laboratory, prions infect cells within one minute of exposure and that the cell plasma membrane is the site of the conversion of prion proteins into the misfolded form.