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The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells
The eukaryotic translation initiation factor 2α (eIF2α) kinase GCN2 is activated by amino acid starvation to elicit a rectifying physiological program known as the Integrated Stress Response (ISR). A role for uncharged tRNAs as activating ligands of yeast GCN2 is supported experimentally. However, m...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6919976/ https://www.ncbi.nlm.nih.gov/pubmed/31749445 http://dx.doi.org/10.7554/eLife.50149 |
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author | Harding, Heather P Ordonez, Adriana Allen, Felicity Parts, Leopold Inglis, Alison J Williams, Roger L Ron, David |
author_facet | Harding, Heather P Ordonez, Adriana Allen, Felicity Parts, Leopold Inglis, Alison J Williams, Roger L Ron, David |
author_sort | Harding, Heather P |
collection | PubMed |
description | The eukaryotic translation initiation factor 2α (eIF2α) kinase GCN2 is activated by amino acid starvation to elicit a rectifying physiological program known as the Integrated Stress Response (ISR). A role for uncharged tRNAs as activating ligands of yeast GCN2 is supported experimentally. However, mouse GCN2 activation has recently been observed in circumstances associated with ribosome stalling with no global increase in uncharged tRNAs. We report on a mammalian CHO cell-based CRISPR-Cas9 mutagenesis screen for genes that contribute to ISR activation by amino acid starvation. Disruption of genes encoding components of the ribosome P-stalk, uL10 and P1, selectively attenuated GCN2-mediated ISR activation by amino acid starvation or interference with tRNA charging without affecting the endoplasmic reticulum unfolded protein stress-induced ISR, mediated by the related eIF2α kinase PERK. Wildtype ribosomes isolated from CHO cells, but not those with P-stalk lesions, stimulated GCN2-dependent eIF2α phosphorylation in vitro. These observations support a model whereby lack of a cognate charged tRNA exposes a latent capacity of the ribosome P-stalk to activate GCN2 in cells and help explain the emerging link between ribosome stalling and ISR activation. |
format | Online Article Text |
id | pubmed-6919976 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-69199762019-12-19 The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells Harding, Heather P Ordonez, Adriana Allen, Felicity Parts, Leopold Inglis, Alison J Williams, Roger L Ron, David eLife Cell Biology The eukaryotic translation initiation factor 2α (eIF2α) kinase GCN2 is activated by amino acid starvation to elicit a rectifying physiological program known as the Integrated Stress Response (ISR). A role for uncharged tRNAs as activating ligands of yeast GCN2 is supported experimentally. However, mouse GCN2 activation has recently been observed in circumstances associated with ribosome stalling with no global increase in uncharged tRNAs. We report on a mammalian CHO cell-based CRISPR-Cas9 mutagenesis screen for genes that contribute to ISR activation by amino acid starvation. Disruption of genes encoding components of the ribosome P-stalk, uL10 and P1, selectively attenuated GCN2-mediated ISR activation by amino acid starvation or interference with tRNA charging without affecting the endoplasmic reticulum unfolded protein stress-induced ISR, mediated by the related eIF2α kinase PERK. Wildtype ribosomes isolated from CHO cells, but not those with P-stalk lesions, stimulated GCN2-dependent eIF2α phosphorylation in vitro. These observations support a model whereby lack of a cognate charged tRNA exposes a latent capacity of the ribosome P-stalk to activate GCN2 in cells and help explain the emerging link between ribosome stalling and ISR activation. eLife Sciences Publications, Ltd 2019-11-21 /pmc/articles/PMC6919976/ /pubmed/31749445 http://dx.doi.org/10.7554/eLife.50149 Text en © 2019, Harding et al http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Cell Biology Harding, Heather P Ordonez, Adriana Allen, Felicity Parts, Leopold Inglis, Alison J Williams, Roger L Ron, David The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells |
title | The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells |
title_full | The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells |
title_fullStr | The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells |
title_full_unstemmed | The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells |
title_short | The ribosomal P-stalk couples amino acid starvation to GCN2 activation in mammalian cells |
title_sort | ribosomal p-stalk couples amino acid starvation to gcn2 activation in mammalian cells |
topic | Cell Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6919976/ https://www.ncbi.nlm.nih.gov/pubmed/31749445 http://dx.doi.org/10.7554/eLife.50149 |
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