Transmissible spongiform encephalopathy or prion disease is triggered by the conversion from cellular prion protein to pathogenic prion protein.

Notably, C-transmembrane form of prion protein and cytosolic prion protein can result in neurodegenerative diseases in cases of error location,aggregation tendency, failure of signal peptides, body stress or incomplete removal of topologic prion protein.

Zhiqi Song and coworkers from China Agricultural University, China introduce two types of disease-associated prion proteins, the cytosolic form and the transmembrane form, during biosynthesis through the endoplasmic reticulum quality-control system, and propose an effective model and testing method for cytosolic forms of prion protein.

Their studies, published in Neural Regeneration Research (Vol. 8, No. 30, 2013), addressing the molecular mechanisms show that the pathogenic factor for prion disease is not limited to the prion protein, but also includes the complex intracellular environment, error location or incomplete removal of topologic prion protein.