Related Experiment Video
Updated: Feb 20, 2026

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle
Published on: March 5, 2019
Phosphorylable tyrosine residue 162 in the double-stranded RNA-dependent kinase PKR modulates its interaction with
Carlos F de la Cruz-Herrera1,2, Maite Baz-Martínez3, Ahmed El Motiam3
1Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid, 28049, Spain. cf.delacruzherrera@utoronto.ca.
Abstract:
Activated dsRNA-dependent serine/threonine kinase PKR phosphorylates the alpha subunit of eukaryotic initiation factor 2 (eIF2α), resulting in a shut-off of general translation, induction of apoptosis, and inhibition of virus replication. PKR can be activated by binding to dsRNA or cellular proteins such as PACT/RAX, or by its conjugation to ISG15 or SUMO. Here, we demonstrate that PKR also interacts with SUMO in a non-covalent manner. We identify the phosphorylable tyrosine residue 162 in PKR (Y162) as a modulator of the PKR-SUMO non-covalent interaction as well as of the PKR SUMOylation. Finally, we show that the efficient SUMO-mediated eIF2α phosphorylation and inhibition of protein synthesis induced by PKR in response to dsRNA depend on this residue. In summary, our data identify a new mechanism of regulation of PKR activity and reinforce the relevance of both, tyrosine phosphorylation and SUMO interaction in controlling the activity of PKR.
Related Concept Videos
Phosphorylation
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein....
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...
Protein Kinases and Phosphatases
Receptor Tyrosine Kinases
PI3K/mTOR/AKT Signaling Pathway

