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The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs

Polysomal messenger RNA (mRNA) populations change rapidly in response to alterations in the physiological status of the cell. For this reason, translational regulation, mediated principally at the level of initiation, plays a key role in the maintenance of cellular homeostasis. In an earlier transla...

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Detalles Bibliográficos
Autores principales: Genolet, Raphael, Rahim, Gwendoline, Gubler-Jaquier, Pascale, Curran, Joseph
Formato: Texto
Lenguaje:English
Publicado: Oxford University Press 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3035446/
https://www.ncbi.nlm.nih.gov/pubmed/20876686
http://dx.doi.org/10.1093/nar/gkq805
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author Genolet, Raphael
Rahim, Gwendoline
Gubler-Jaquier, Pascale
Curran, Joseph
author_facet Genolet, Raphael
Rahim, Gwendoline
Gubler-Jaquier, Pascale
Curran, Joseph
author_sort Genolet, Raphael
collection PubMed
description Polysomal messenger RNA (mRNA) populations change rapidly in response to alterations in the physiological status of the cell. For this reason, translational regulation, mediated principally at the level of initiation, plays a key role in the maintenance of cellular homeostasis. In an earlier translational profiling study, we followed the impact of rapamycin on polysome re-seeding. Despite the overall negative effect on transcript recruitment, we nonetheless observed that some mRNAs were significantly less affected. Consequently, their relative polysomal occupancy increased in the rapamycin-treated cells. The behaviour of one of these genes, mdm2, has been further analysed. Despite the absence of internal ribosome entry site activity we demonstrate, using a dual reporter assay, that both the reported mdm2 5′-UTRs confer resistance to rapamycin relative to the 5′-UTR of β-actin. This relative resistance is responsive to the downstream targets mTORC1 but did not respond to changes in the La protein, a reported factor acting positively on MDM2 translational expression. Furthermore, extended exposure to rapamycin in the presence of serum increased the steady-state level of the endogenous MDM2 protein. However, this response was effectively reversed when serum levels were reduced. Taken globally, these studies suggest that experimental conditions can dramatically modulate the expressional output during rapamycin exposure.
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spelling pubmed-30354462011-02-08 The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs Genolet, Raphael Rahim, Gwendoline Gubler-Jaquier, Pascale Curran, Joseph Nucleic Acids Res Molecular Biology Polysomal messenger RNA (mRNA) populations change rapidly in response to alterations in the physiological status of the cell. For this reason, translational regulation, mediated principally at the level of initiation, plays a key role in the maintenance of cellular homeostasis. In an earlier translational profiling study, we followed the impact of rapamycin on polysome re-seeding. Despite the overall negative effect on transcript recruitment, we nonetheless observed that some mRNAs were significantly less affected. Consequently, their relative polysomal occupancy increased in the rapamycin-treated cells. The behaviour of one of these genes, mdm2, has been further analysed. Despite the absence of internal ribosome entry site activity we demonstrate, using a dual reporter assay, that both the reported mdm2 5′-UTRs confer resistance to rapamycin relative to the 5′-UTR of β-actin. This relative resistance is responsive to the downstream targets mTORC1 but did not respond to changes in the La protein, a reported factor acting positively on MDM2 translational expression. Furthermore, extended exposure to rapamycin in the presence of serum increased the steady-state level of the endogenous MDM2 protein. However, this response was effectively reversed when serum levels were reduced. Taken globally, these studies suggest that experimental conditions can dramatically modulate the expressional output during rapamycin exposure. Oxford University Press 2011-02 2010-09-28 /pmc/articles/PMC3035446/ /pubmed/20876686 http://dx.doi.org/10.1093/nar/gkq805 Text en © The Author(s) 2010. Published by Oxford University Press. http://creativecommons.org/licenses/by-nc/2.5 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Molecular Biology
Genolet, Raphael
Rahim, Gwendoline
Gubler-Jaquier, Pascale
Curran, Joseph
The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs
title The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs
title_full The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs
title_fullStr The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs
title_full_unstemmed The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs
title_short The translational response of the human mdm2 gene in HEK293T cells exposed to rapamycin: a role for the 5′-UTRs
title_sort translational response of the human mdm2 gene in hek293t cells exposed to rapamycin: a role for the 5′-utrs
topic Molecular Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3035446/
https://www.ncbi.nlm.nih.gov/pubmed/20876686
http://dx.doi.org/10.1093/nar/gkq805
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