PKR and PP1C Polymorphisms in Alzheimer’s Disease Risk

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by senile plaques and neurofibrillary tangles. Senile plaques are deposits of amyloid ß-peptide (Aß) produced by the cleavage of a transmembrane protein termed Amyloid Precursor Protein (APP). The amyloidogenic cleavage of APP is performed by γ-secretase complex and ß-site APP cleaving enzyme 1 (BACE1), a key enzyme in AD that can be activated by different noxious stimuli. Interestingly, some viruses could activate double-stranded RNA-activated protein kinase (PKR), which phosphorylates Eukaryotic Initiation Factor 2 alpha (eIF2α). This phosphorylation stops global translation to avoid any synthesis of viral infective proteins, but paradoxically up-regulates BACE1 translation. One of the viral mechanisms to circumvent eIF2α phos-phorylation is the recruitment of protein phosphatase 1 (PP1), to fully dephosphorylate eIF2α and allow viral protein synthesis. Due to the functional relationship between BACE1, PKR, PP1 and AD we have performed a large (1122 cases and 1191 control individuals) case-control genetic analysis using two biallelic polymorphisms rs2254958 an