Effects of the Pathological E200K Mutation on Human Prion Protein: A Computational screening and Molecular Dynamic approach

The Human Prion protein gene (PRNP) is mapped to short arm of chromosome 20 (20pter-12). Prion disease is associated with mutations in the Prion Protein encoding gene sequence. The mutations that occur in the prion protein could be divided into two types based on their influence on pathogenic potential: 1. Mutations that cause disease. 2. Disease-resistance mutations. Earlier studies found that the mutation G127V in the PRNP increases protein stability, whereas the mutation E200K, which has the highest mutation rate in the Prion protein, causes Creutzfeldt–Jakob disease (CJD) in humans and induces protein aggregation. We used a variety of bioinformatic algorithms, including SIFT, PolyPhen, I-Mutant, PhD-SNP, and SNP&GO, to predict the association of the E200K mutation with Prion disease. MD simulation is performed and graphs for RMSD, RMSF, Rg, DSSP, PCA, porcupine and FEL are generated to confirm and prove the stability of the wild type and mutant protein structures. The protein is analyzed for aggregation, and the results indicates more fluctuations in the protein structure during the simulation by the E200K mutation, however the G127V mutation makes protein structure stable against aggregation during the simulation.

Clinical Features of Genetic Creutzfeldt-Jakob Disease with E200K Mutation

Although genetic Creutzfeldt-Jakob disease (CJD) is a rare neurodegenerative disorder, cases of genetic CJD with E200K mutation are being increasingly reported in Korea. However, the clinical features and course of genetic CJD with E200K mutation in Korea remain unclear. We describe the clinical features and course of genetic CJD with E200K mutation in a patient who initially presented with rapid progressive memory impairment and myoclonus.

Genetic Risk Factors of Creutzfeldt-Jakob Disease in the Population of Newborns in Slovakia

The most frequent human prion disease is Creutzfeldt–Jakob disease (CJD). It occurs as sporadic (sCJD), genetic (gCJD), iatrogenic (iCJD) form and as variant CJD. The genetic form represents about 10–15% of confirmed cases worldwide, in Slovakia as much as 65–75%. Focal accumulation of gCJD was confirmed in Orava region. The most common point mutation of the prion protein gene (PRNP) is E200K. CJD has a long asymptomatic phase and it is not known when the carriers of the mutation E200K become infectious. Precautions to prevent iCJD are focused especially on clinical CJD cases, but asymptomatic CJD-specific mutation carriers cannot be excluded, and represent a potential genetic CJD-risk group. The aim of this study was to determine the occurrence, frequency and geographic distribution of the E200K mutation among the newborns, comparing the areas of focal accumulation of gCJD with extra-focal ones, as well as distribution of the polymorphism M129V of the PRNP gene. A total of 2915 samples of dry blood spots from anonymous newborns were analyzed. We used RealTime PCR method to determine the presence of the E200K mutation and the M129V polymorphism. Genetic testing revealed 13 carriers of the E200K mutation. Investigation of the M129V polymorphism affirmed higher representation of methionine homozygotes (48% MM, 44% MV, 8% VV). Achieved results fully confirmed our previous observations concerning both the specific and nonspecific genetic CJD risk among the Slovak general population. The 48% of methionine homozygotes and 4 carriers of the E200K mutation among 1000 live-born children in Slovakia underline the benefits of genetic testing.

Pathogenic Prion Protein Isoforms Are Not Present in Cerebral Organoids Generated from Asymptomatic Donors Carrying the E200K Mutation Associated with Familial Prion Disease

Cerebral organoids (COs) are a self-organizing three-dimensional brain tissue mimicking the human cerebral cortex. COs are a promising new system for modelling pathological features of neurological disorders, including prion diseases. COs expressing normal prion protein (PrPC) are susceptible to prion infection when exposed to the disease isoforms of PrP (PrPD). This causes the COs to develop aspects of prion disease pathology considered hallmarks of disease, including the production of detergent-insoluble, protease-resistant misfolded PrPD species capable of seeding the production of more misfolded species. To determine whether COs can model aspects of familial prion diseases, we produced COs from donor fibroblasts carrying the E200K mutation, the most common cause of human familial prion disease. The mature E200K COs were assessed for the hallmarks of prion disease. We found that up to 12 months post-differentiation, E200K COs harbored no PrPD as confirmed by the absence of detergent-insoluble, protease-resistant, and seeding-active PrP species. Our results suggest that the presence of the E200K mutation within the prion gene is insufficient to cause disease in neuronal tissue. Therefore, other factors, such as further genetic modifiers or aging processes, may influence the onset of misfolding.