EIF2AK2 (Eukaryotic Translation Initiation Factor 2 Alpha Kinase 2), more commonly known as PKR (Protein Kinase R), is a serine/threonine kinase that serves as a critical sensor of cellular stress and a key activator of the integrated stress response (ISR). Originally characterized for its role in antiviral defense, where it is activated by double-stranded RNA to inhibit viral protein synthesis, PKR has emerged as an important player in neurodegenerative disease pathogenesis. The kinase is activated in Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, where it contributes to synaptic dysfunction, protein aggregation, and neuronal cell death.
| PKR (EIF2AK2) Kinase | |
|---|---|
| Gene Symbol | EIF2AK2 |
| Protein Name | Protein Kinase R (PKR) |
| Chromosome | 2p22.2 |
| NCBI Gene ID | [2025](https://www.ncbi.nlm.nih.gov/gene/2025) |
| OMIM | 603013 |
| Ensembl ID | ENSG00000055332 |
| UniProt ID | [P19589](https://www.uniprot.org/uniprot/P19589) |
| Protein Family | eIF2α kinase family |
| Subcellular Location | Cytoplasm, nucleus (upon activation) |
| Associated Diseases | Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, ALS, Viral Encephalitis |
The EIF2AK2 gene is located on chromosome 2 (2p22.2), spanning approximately 50 kb of genomic DNA. The gene consists of 16 exons that encode a protein of 551 amino acids. The promoter contains interferon-stimulated response elements (ISRE), NF-κB binding sites, and p53 response elements.
EIF2AK2 shows strong evolutionary conservation:
EIF2AK2 contains several functional domains:
EIF2AK2 catalyzes eIF2α phosphorylation:
PKR serves multiple cellular functions:
Translation regulation:
Apoptosis regulation:
EIF2AK2 shows ubiquitous expression:
High expression:
EIF2AK2 localizes primarily to the cytoplasm:
PKR is a key activator of the integrated stress response (ISR):
PKR contributes to AD through multiple mechanisms:
Protein aggregation:
Synaptic dysfunction:
PKR involvement in PD relates to dopaminergic neuron vulnerability:
PKR is prominently involved in HD pathogenesis:
EIF2AK2 interacts with:
EIF2AK2 integrates with:
Targeting PKR for therapeutic benefit:
Direct inhibitors:
Indirect modulators:
Eif2ak2 knockout mice show phenotypes:
EIF2AK2 connects to multiple NeuroWiki pages: