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Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules

The RNA-binding protein Fragile X Mental Retardation (FMRP) is an evolutionarily conserved protein that is particularly abundant in the brain due to its high expression in neurons. FMRP deficiency causes fragile X mental retardation syndrome. In neurons, FMRP controls the translation of target mRNAs...

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Autores principales: Gareau, Cristina, Houssin, Elise, Martel, David, Coudert, Laetitia, Mellaoui, Samia, Huot, Marc-Etienne, Laprise, Patrick, Mazroui, Rachid
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3567066/
https://www.ncbi.nlm.nih.gov/pubmed/23408971
http://dx.doi.org/10.1371/journal.pone.0055342
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author Gareau, Cristina
Houssin, Elise
Martel, David
Coudert, Laetitia
Mellaoui, Samia
Huot, Marc-Etienne
Laprise, Patrick
Mazroui, Rachid
author_facet Gareau, Cristina
Houssin, Elise
Martel, David
Coudert, Laetitia
Mellaoui, Samia
Huot, Marc-Etienne
Laprise, Patrick
Mazroui, Rachid
author_sort Gareau, Cristina
collection PubMed
description The RNA-binding protein Fragile X Mental Retardation (FMRP) is an evolutionarily conserved protein that is particularly abundant in the brain due to its high expression in neurons. FMRP deficiency causes fragile X mental retardation syndrome. In neurons, FMRP controls the translation of target mRNAs in part by promoting dynamic transport in and out neuronal RNA granules. We and others have previously shown that upon stress, mammalian FMRP dissociates from translating polysomes to localize into neuronal-like granules termed stress granules (SG). This localization of FMRP in SG is conserved in Drosophila. Whether FMRP plays a key role in SG formation, how FMRP is recruited into SG, and whether its association with SG is dynamic are currently unknown. In contrast with mammalian FMRP, which has two paralog proteins, Drosophila FMR1 (dFMRP) is encoded by a single gene that has no paralog. Using this genetically simple model, we assessed the role of dFMRP in SG formation and defined the determinants required for its recruitment in SG as well as its dynamics in SG. We show that dFMRP is dispensable for SG formation in vitro and ex vivo. FRAP experiments showed that dFMRP shuttles in and out SG. The shuttling activity of dFMRP is mediated by a protein-protein interaction domain located at the N-terminus of the protein. This domain is, however, dispensable for the localization of dFMRP in SG. This localization of dFMRP in SG requires the KH and RGG motifs which are known to mediate RNA binding, as well as the C-terminal glutamine/asparagine rich domain. Our studies thus suggest that the mechanisms controlling the recruitment of FMRP into SG and those that promote its shuttling between granules and the cytosol are uncoupled. To our knowledge, this is the first demonstration of the regulated shuttling activity of a SG component between RNA granules and the cytosol.
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spelling pubmed-35670662013-02-13 Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules Gareau, Cristina Houssin, Elise Martel, David Coudert, Laetitia Mellaoui, Samia Huot, Marc-Etienne Laprise, Patrick Mazroui, Rachid PLoS One Research Article The RNA-binding protein Fragile X Mental Retardation (FMRP) is an evolutionarily conserved protein that is particularly abundant in the brain due to its high expression in neurons. FMRP deficiency causes fragile X mental retardation syndrome. In neurons, FMRP controls the translation of target mRNAs in part by promoting dynamic transport in and out neuronal RNA granules. We and others have previously shown that upon stress, mammalian FMRP dissociates from translating polysomes to localize into neuronal-like granules termed stress granules (SG). This localization of FMRP in SG is conserved in Drosophila. Whether FMRP plays a key role in SG formation, how FMRP is recruited into SG, and whether its association with SG is dynamic are currently unknown. In contrast with mammalian FMRP, which has two paralog proteins, Drosophila FMR1 (dFMRP) is encoded by a single gene that has no paralog. Using this genetically simple model, we assessed the role of dFMRP in SG formation and defined the determinants required for its recruitment in SG as well as its dynamics in SG. We show that dFMRP is dispensable for SG formation in vitro and ex vivo. FRAP experiments showed that dFMRP shuttles in and out SG. The shuttling activity of dFMRP is mediated by a protein-protein interaction domain located at the N-terminus of the protein. This domain is, however, dispensable for the localization of dFMRP in SG. This localization of dFMRP in SG requires the KH and RGG motifs which are known to mediate RNA binding, as well as the C-terminal glutamine/asparagine rich domain. Our studies thus suggest that the mechanisms controlling the recruitment of FMRP into SG and those that promote its shuttling between granules and the cytosol are uncoupled. To our knowledge, this is the first demonstration of the regulated shuttling activity of a SG component between RNA granules and the cytosol. Public Library of Science 2013-02-07 /pmc/articles/PMC3567066/ /pubmed/23408971 http://dx.doi.org/10.1371/journal.pone.0055342 Text en © 2013 Gareau et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Gareau, Cristina
Houssin, Elise
Martel, David
Coudert, Laetitia
Mellaoui, Samia
Huot, Marc-Etienne
Laprise, Patrick
Mazroui, Rachid
Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules
title Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules
title_full Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules
title_fullStr Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules
title_full_unstemmed Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules
title_short Characterization of Fragile X Mental Retardation Protein Recruitment and Dynamics in Drosophila Stress Granules
title_sort characterization of fragile x mental retardation protein recruitment and dynamics in drosophila stress granules
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3567066/
https://www.ncbi.nlm.nih.gov/pubmed/23408971
http://dx.doi.org/10.1371/journal.pone.0055342
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