The prion protein (PrP) has been extensively studied because of its central role in a group of neurodegenerative conditions collectively known as prion diseases. While a wealth of information is available for the pathology and transmission of these diseases, the molecular mechanisms involved are not yet clearly defined.

So, how do we learn about the molecular mechanisms underlying the pathogenic role of the PrP in disease? What have we learned about the physiological role of the PrP? Defining PrP function may shed light on pathological processes involved in prion diseases. The PrP has been shown to participate in several biological processes, including neuritogenesis, neuronal homeostasis, cell signalling, cell adhesion, and a protective role against stress. This pleiotropism has led to confusion about the precise molecular function(s) of the PrP. This essay shall attempt to clarify the most relevant physiological roles of the protein in the context of the central and peripheral nervous system.