Prion proteins in signal transduction (original) (raw)

A prion protein is essentially a protein that can replicate itself. The mechanism of propagation is characterized by the ability of the protein in the prion-like state to catalytically convert the homologous natively-folded protein into a likeness of itself. This switch in conformation forms the basis for the infectious nature of prion proteins. The first such protein to be discovered was the cellular prion protein (PrP). Post-translational modification of native PrPC into its pathogenic isoform (PrPSc) is the molecular signature underlying a group of fatal mammalian neurodegenerative disorders (transmissible spongiform encephalopathies). Interestingly, recent studies on the physiological function of PrPC strongly indicate a critical role of the molecule in activation of signalling pathways linked to maintenance of mitochondrial integrity and cell survival. These include the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways. Many interaction p...