Cellular Prion Protein: From Physiology to Pathology
نویسندگان
چکیده
The human cellular prion protein (PrP(C)) is a glycosylphosphatidylinositol (GPI) anchored membrane glycoprotein with two N-glycosylation sites at residues 181 and 197. This protein migrates in several bands by Western blot analysis (WB). Interestingly, PNGase F treatment of human brain homogenates prior to the WB, which is known to remove the N-glycosylations, unexpectedly gives rise to two dominant bands, which are now known as C-terminal (C1) and N-terminal (N1) fragments. This resembles the β-amyloid precursor protein (APP) in Alzheimer disease (AD), which can be physiologically processed by α-, β-, and γ-secretases. The processing of APP has been extensively studied, while the identity of the cellular proteases involved in the proteolysis of PrP(C) and their possible role in prion biology has remained limited and controversial. Nevertheless, there is a strong correlation between the neurotoxicity caused by prion proteins and the blockade of their normal proteolysis. For example, expression of non-cleavable PrP(C) mutants in transgenic mice generates neurotoxicity, even in the absence of infectious prions, suggesting that PrP(C) proteolysis is physiologically and pathologically important. As many mouse models of prion diseases have recently been developed and the knowledge about the proteases responsible for the PrP(C) proteolysis is accumulating, we examine the historical experimental evidence and highlight recent studies that shed new light on this issue.
منابع مشابه
A Study on The Effect of Temperature on Human Prion Protein Structure through Molecular Dynamic Simulation
Background & Aims: The normal form of the prion protein is called PrPC and its infectious form is called PrPSc. This protein functions like a crystallized core for the transformation of PrPc into an abnormal PrPSc. The aim of the present study was to investigate the effect of temperature on human prion protein structure through molecular dynamic simulation. Methods: In this research, the GROMAC...
متن کاملTreatment of Prion Disease with Heterologous Prion Proteins
Prion diseases such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy in cattle, and scrapie in sheep are fatal neurodegenerative diseases for which there is no effective treatment. The pathology of these diseases involves the conversion of a protease sensitive form of the cellular prion protein (PrPC) into a protease resistant infectious form (PrPsc or PrPres). Both in v...
متن کاملPolymorphism of Prion Protein Gene (PRNP) in Iranian Holstein and Two Local Cattle Populations (Golpayegani and Sistani) of Iran
Bovine spongiform encephalopathy (BSE) is a fatal infectious neurodegenerative disease in cattle, characterized by the accumulation of an abnormal, proteaseresistant prion protein (PrPSc) in the brain. BSE is similar to scrapie in sheep and goats and Creuzfeldt-Jakob disease in humans. Susceptibility in cattle hasbeen shown to be under the influence of two polymorphic locations, which are...
متن کاملActivation of the unfolded protein response and granulovacuolar degeneration are not common features of human prion pathology
Human prion diseases are fatal neurodegenerative disorders with a genetic, sporadic or infectiously acquired aetiology. Neuropathologically, human prion diseases are characterized by deposition of misfolded prion protein and neuronal loss. In post-mortem brain tissue from patients with other neurodegenerative diseases characterized by protein misfolding, including Alzheimer's disease (AD) and f...
متن کاملThe molecular pathology of prion diseases.
15 Abstract Prion diseases, or transmissible spongiform encephalopathies (TSEs), are a group of invariably fatal neurodegenerative disorders. Uniquely, they may present as sporadic, inherited, or infectious forms, all of which involve conversion of the normal cellular prion protein (PrP) into a pathogenic likeness of itself (PrP). Formation of neurotoxic PrP and/or loss of the normal function o...
متن کامل