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PKR is Activated by Cellular DsRNAs During Mitosis and Acts As a Mitotic Regulator

Overview
Journal Genes Dev
Specialty Molecular Biology
Date 2014 Jun 19
PMID 24939934
Citations 76
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Abstract

dsRNA-dependent protein kinase R (PKR) is a ubiquitously expressed enzyme well known for its roles in immune response. Upon binding to viral dsRNA, PKR undergoes autophosphorylation, and the phosphorylated PKR (pPKR) regulates translation and multiple signaling pathways in infected cells. Here, we found that PKR is activated in uninfected cells, specifically during mitosis, by binding to dsRNAs formed by inverted Alu repeats (IRAlus). While PKR and IRAlu-containing RNAs are segregated in the cytosol and nucleus of interphase cells, respectively, they interact during mitosis when nuclear structure is disrupted. Once phosphorylated, PKR suppresses global translation by phosphorylating the α subunit of eukaryotic initiation factor 2 (eIF2α). In addition, pPKR acts as an upstream kinase for c-Jun N-terminal kinase and regulates the levels of multiple mitotic factors such as cyclins A and B and Polo-like kinase 1 and phosphorylation of histone H3. Disruption of PKR activation via RNAi or expression of a transdominant-negative mutant leads to misregulation of the mitotic factors, delay in mitotic progression, and defects in cytokinesis. Our study unveils a novel function of PKR and endogenous dsRNAs as signaling molecules during the mitosis of uninfected cells.

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References
1.
Gerlitz G, Jagus R, Elroy-Stein O . Phosphorylation of initiation factor-2 alpha is required for activation of internal translation initiation during cell differentiation. Eur J Biochem. 2002; 269(11):2810-9. DOI: 10.1046/j.1432-1033.2002.02974.x. View

2.
Peisley A, Hur S . Multi-level regulation of cellular recognition of viral dsRNA. Cell Mol Life Sci. 2012; 70(11):1949-63. PMC: 7079809. DOI: 10.1007/s00018-012-1149-4. View

3.
Brosius J . RNAs from all categories generate retrosequences that may be exapted as novel genes or regulatory elements. Gene. 1999; 238(1):115-34. DOI: 10.1016/s0378-1119(99)00227-9. View

4.
Benkirane M, Neuveut C, Chun R, Smith S, Samuel C, Gatignol A . Oncogenic potential of TAR RNA binding protein TRBP and its regulatory interaction with RNA-dependent protein kinase PKR. EMBO J. 1997; 16(3):611-24. PMC: 1169664. DOI: 10.1093/emboj/16.3.611. View

5.
Meurs E, Watanabe Y, Kadereit S, Barber G, Katze M, Chong K . Constitutive expression of human double-stranded RNA-activated p68 kinase in murine cells mediates phosphorylation of eukaryotic initiation factor 2 and partial resistance to encephalomyocarditis virus growth. J Virol. 1992; 66(10):5805-14. PMC: 241456. DOI: 10.1128/JVI.66.10.5805-5814.1992. View