PKR Recombinant Rabbit Monoclonal Antibody [SC06-37]

Function

An interferon-inducible, RNA-dependent protein serine/threonine kinase (PKR) has been described. PKR in earlier literature is variously known as DAI, dsJ, PI kinase, p65, p67 or TIK for the mouse kinase; and p68 or p69 for the human kinase. The PKR kinase substrate is the a subunit of protein synthesis initiation factor eIF-2. Phosphorylation of eIF-2a on serine-51 results in inhibition of translation. Molecular cDNA clones have been isolated from both human and mouse cells. The serine/threonine kinase catalytic domains map to the carboxy terminal half of the protein while the RNA-binding domains are located in the amino terminal region. Three kinds of regulation of PKR enzymatic activity have been described. These include transcriptional regulation in response to interferon, an autoregulatory mechanism controlling PKR expression at the level of translation and post-translational regulation by RNA mediated autophosphorylation.

Background References

1. Maity B et al. Molecular mechanism of the anti-inflammatory activity of a natural diarylnonanoid, malabaricone C. Free Radic Biol Med 52:1680-1691 (2012).

2. Lindquist ME et al. Activation of protein kinase R is required for induction of stress granules by respiratory syncytial virus but dispensable for viral replication. Virology 413:103-10 (2011).

Sequence Similarity

Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. GCN2 subfamily.

Tissue Specificity

Highly expressed in thymus, spleen and bone marrow compared to non-hematopoietic tissues such as small intestine, liver, or kidney tissues. Colocalizes with GSK3B and TAU in the Alzheimer disease (AD) brain. Elevated levels seen in breast and colon carcinomas, and which correlates with tumor progression and invasiveness or risk of progression.

Post-translational Modification

Autophosphorylated on several Ser, Thr and Tyr residues. Autophosphorylation of Thr-451 is dependent on Thr-446 and is stimulated by dsRNA binding and dimerization. Autophosphorylation apparently leads to the activation of the kinase. Tyrosine autophosphorylation is essential for efficient dsRNA-binding, dimerization, and kinase activation.

Subcellular Location

Nucleus, Cytoplasm, perinuclear region.

UNIPROT

SwissProt: P19525 Human

Synonyms