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The ribotoxic stress response, which is conserved between prokaryotes and eukaryotes, is a cellular reaction to cytotoxic interference with the function of the 3′-end of the large (23 S/28 S) ribosomal RNA. The 3′-end of the large rRNA is directly involved in the three sequential steps of translational elongation: the aminoacyl-tRNA binding, the peptidyl transfer, and the ribosomal translocation. In mammalian cells, the ribotoxic stress response involves activation of the stress-activated protein kinase/c-Jun NH2-terminal kinase and the p38 mitogen-activated protein kinase and transcriptional induction of immediate early genes such as c-fos and c-jun. Active ribosomes are essential mediators of the ribotoxic stress response. We demonstrate here that the transcriptional response of mammalian cells to ultraviolet radiation (UV response) displays the characteristics of a ribotoxic stress response, inasmuch as (i) the activation of stress kinases and gene expression in response to UV requires the presence of active ribosomes at the moment of irradiation; (ii) UV irradiation inhibits protein synthesis; and (iii) irradiation of cells with UV causes specific damage to the 3′-end of the 28 S rRNA. In contrast, the activation of the stress kinases by hyperosmolarity, by the DNA-cross-linking agent diepoxybutane, or by growth factors and cytokines does not depend on the presence of active ribosomes. Our results identify UV as a potential ribotoxic stressor and support the notion that some of the cellular signaling cascades in response to UV might be generated in the ribosome, possibly triggered by damage to rRNA.


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Iordanov, M. S., Pribnow, D., Magun, J. L., Dinh, T.-H., Pearson, J. A., & Magun, B. E. (1998). Ultraviolet radiation triggers the ribotoxic stress response in mammalian cells. The Journal of Biological Chemistry, 273(25), 15794-15803. doi:10.1074/jbc.273.25.15794


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The Journal of Biological Chemistry


CU Commons -- Math and Science Department Faculty Research

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Microbiology Commons