The double life of the prion protein

The increasingly high-profile prion protein is involved in a class of devastating neurological diseases, including human Creutzfeld–Jakob disease, scrapie in sheep and goats, and ‘mad cow disease’. It is highly conserved among mammalian species, is found on the surface of cells that produce it, and is expressed in many tissues, including the brain. Like the superhero Batman, the prion protein may lead a double life. Just as one must get to know Batman’s alter ego — mild-mannered Gotham City millionaire Bruce Wayne — to understand the caped crusader, understanding the role of the prion protein in disease may require an appreciation of the function of its seemingly innocuous cellular form.