Related Experiment Video
Updated: Jun 21, 2026

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle
Published on: March 5, 2019
PKR, the double stranded RNA-dependent protein kinase as a critical target in Alzheimer's disease
Milena Morel1, Julien Couturier, Claire Lafay-Chebassier
1Research Group on Brain Aging (EA 3808) University of Poitiers, Poitiers Cedex, France.
Abstract:
Amyloid beta-peptide (Abeta) deposits and neurofibrillary tangles are key hallmarks in Alzheimer's disease (AD). Abeta stimulates many signal transducers involved in the neuronal death. However, many mechanisms remain to be elucidated because no definitive therapy of AD exists. Some studies have focused on the control of translation which involves eIF2 and eIF4E, main eukaryotic factors of initiation. The availability of these factors depends on the activation of the double-stranded RNA-dependent protein kinase (PKR) and the mammalian target of rapamycin (mTOR), respectively. mTOR positively regulates the translation while PKR results in a protein synthesis shutdown. Many studies demonstrated that the PKR signalling pathway is up-regulated in cellular and animal models of AD and in the brain of AD patients. Interestingly, our results showed that phosphorylated PKR and eIF2alpha levels were significantly increased in lymphocytes of AD patients. These modifications were significantly correlated with cognitive and memory test scores performed in AD patients. On the contrary, the mTOR signalling pathway is down-regulated in cellular and animal models of AD. Recently, we showed that p53, regulated protein in development and DNA damage response 1 and tuberous sclerosis complex 2 could represent molecular links between PKR and mTOR signalling pathways. PKR could be an early biomarker of the neuronal death and a critical target for a therapeutic programme in AD.
Insights
Alzheimer's disease (AD) involves amyloid beta-peptide deposits and neurofibrillary tangles. Increased PKR signaling in AD patients correlates with cognitive decline, suggesting PKR as an early biomarker and therapeutic target.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- Alzheimer's disease (AD) is characterized by amyloid beta-peptide (Abeta) deposits and neurofibrillary tangles, leading to neuronal death.
- Dysregulation of protein translation, controlled by eukaryotic initiation factors (eIF2 and eIF4E), is implicated in AD pathogenesis.
- The double-stranded RNA-dependent protein kinase (PKR) pathway, which inhibits protein synthesis, is upregulated in AD, while the mammalian target of rapamycin (mTOR) pathway, promoting translation, is downregulated.
Purpose of the Study:
- To investigate the role of PKR and mTOR signaling pathways in Alzheimer's disease.
- To determine if PKR and eIF2alpha modifications in lymphocytes correlate with cognitive function in AD patients.
- To explore potential molecular links between PKR and mTOR pathways, such as p53 and tuberous sclerosis complex 2.
Main Methods:
- Analysis of phosphorylated PKR and eIF2alpha levels in lymphocytes from AD patients.
- Correlation analysis between PKR/eIF2alpha levels and cognitive/memory test scores.
- Review of existing literature on PKR and mTOR signaling in AD models and patients.
Main Results:
- Phosphorylated PKR and eIF2alpha levels were significantly elevated in lymphocytes of AD patients.
- These elevated levels showed a significant correlation with cognitive and memory test performance.
- PKR signaling is upregulated, while mTOR signaling is downregulated in AD, with potential links via p53 and TSC2.
Conclusions:
- PKR activation and subsequent protein synthesis inhibition may contribute to neuronal dysfunction in AD.
- Elevated PKR and eIF2alpha in peripheral cells could serve as early biomarkers for AD.
- Targeting the PKR pathway presents a potential therapeutic strategy for Alzheimer's disease.
Related Concept Videos
Enzyme-linked Receptors
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Alzheimer Disease ll: Pathophysiology
Alzheimer Disease l: Introduction
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Alzheimer's Disease: Treatment
Alzheimer's Disease: Overview
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau...

