Prions: protein only or something more? Overview of potential prion cofactors.
Résumé
Transmissible spongiform encephalopathies (TSEs) in humans and animals are attributed to protein-only infectious agents, called prions. Prions have been proposed to arise from the conformational conversion of the cellular protein PrP(C) into a misfolded form (e.g., PrP(Sc) for scrapie), which precipitates into aggregates and fibrils. It has been proposed that the conversion process is triggered by the interaction of the infectious form (PrP(Sc)) with the cellular form (PrP(C)) or might result from a mutation in the gene for PrP(C). However, until recently, all efforts to reproduce this process in vitro had failed, suggesting that host factors are necessary for prion replication. In this review we discuss recent findings such as the cellular factors that might be involved in the conformational conversion of prion proteins and the potential mechanisms by which they could operate.
Mots clés
Animals
Brain Chemistry
Cell-Free System
Endocytosis
Gene Expression Profiling
Humans
Intracellular Signaling Peptides and Proteins
Lipid Metabolism
Mice
Transgenic
Peptide Hydrolases
PrPSc Proteins
Prion Diseases
Protease Inhibitors
Protein Binding
Protein Folding
Protein Interaction Mapping
Protein Processing
Post-Translational
Solubility