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Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant disorder with progressive degeneration of cerebellar Purkinje cells (PCs) and other neurons caused by expansion of a glutamine (Q) tract in the ATXN2 protein. We generated BAC transgenic lines in which the full-length human ATXN2 gene was...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Public Library of Science
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4406435/ https://www.ncbi.nlm.nih.gov/pubmed/25902068 http://dx.doi.org/10.1371/journal.pgen.1005182 |
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author | Dansithong, Warunee Paul, Sharan Figueroa, Karla P. Rinehart, Marc D. Wiest, Shaina Pflieger, Lance T. Scoles, Daniel R. Pulst, Stefan M. |
author_facet | Dansithong, Warunee Paul, Sharan Figueroa, Karla P. Rinehart, Marc D. Wiest, Shaina Pflieger, Lance T. Scoles, Daniel R. Pulst, Stefan M. |
author_sort | Dansithong, Warunee |
collection | PubMed |
description | Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant disorder with progressive degeneration of cerebellar Purkinje cells (PCs) and other neurons caused by expansion of a glutamine (Q) tract in the ATXN2 protein. We generated BAC transgenic lines in which the full-length human ATXN2 gene was transcribed using its endogenous regulatory machinery. Mice with the ATXN2 BAC transgene with an expanded CAG repeat (BAC-Q72) developed a progressive cellular and motor phenotype, whereas BAC mice expressing wild-type human ATXN2 (BAC-Q22) were indistinguishable from control mice. Expression analysis of laser-capture microdissected (LCM) fractions and regional expression confirmed that the BAC transgene was expressed in PCs and in other neuronal groups such as granule cells (GCs) and neurons in deep cerebellar nuclei as well as in spinal cord. Transcriptome analysis by deep RNA-sequencing revealed that BAC-Q72 mice had progressive changes in steady-state levels of specific mRNAs including Rgs8, one of the earliest down-regulated transcripts in the Pcp2-ATXN2[Q127] mouse line. Consistent with LCM analysis, transcriptome changes analyzed by deep RNA-sequencing were not restricted to PCs, but were also seen in transcripts enriched in GCs such as Neurod1. BAC-Q72, but not BAC-Q22 mice had reduced Rgs8 mRNA levels and even more severely reduced steady-state protein levels. Using RNA immunoprecipitation we showed that ATXN2 interacted selectively with RGS8 mRNA. This interaction was impaired when ATXN2 harbored an expanded polyglutamine. Mutant ATXN2 also reduced RGS8 expression in an in vitro coupled translation assay when compared with equal expression of wild-type ATXN2-Q22. Reduced abundance of Rgs8 in Pcp2-ATXN2[Q127] and BAC-Q72 mice supports our observations of a hyper-excitable mGluR1-ITPR1 signaling axis in SCA2, as RGS proteins are linked to attenuating mGluR1 signaling. |
format | Online Article Text |
id | pubmed-4406435 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-44064352015-05-07 Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model Dansithong, Warunee Paul, Sharan Figueroa, Karla P. Rinehart, Marc D. Wiest, Shaina Pflieger, Lance T. Scoles, Daniel R. Pulst, Stefan M. PLoS Genet Research Article Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant disorder with progressive degeneration of cerebellar Purkinje cells (PCs) and other neurons caused by expansion of a glutamine (Q) tract in the ATXN2 protein. We generated BAC transgenic lines in which the full-length human ATXN2 gene was transcribed using its endogenous regulatory machinery. Mice with the ATXN2 BAC transgene with an expanded CAG repeat (BAC-Q72) developed a progressive cellular and motor phenotype, whereas BAC mice expressing wild-type human ATXN2 (BAC-Q22) were indistinguishable from control mice. Expression analysis of laser-capture microdissected (LCM) fractions and regional expression confirmed that the BAC transgene was expressed in PCs and in other neuronal groups such as granule cells (GCs) and neurons in deep cerebellar nuclei as well as in spinal cord. Transcriptome analysis by deep RNA-sequencing revealed that BAC-Q72 mice had progressive changes in steady-state levels of specific mRNAs including Rgs8, one of the earliest down-regulated transcripts in the Pcp2-ATXN2[Q127] mouse line. Consistent with LCM analysis, transcriptome changes analyzed by deep RNA-sequencing were not restricted to PCs, but were also seen in transcripts enriched in GCs such as Neurod1. BAC-Q72, but not BAC-Q22 mice had reduced Rgs8 mRNA levels and even more severely reduced steady-state protein levels. Using RNA immunoprecipitation we showed that ATXN2 interacted selectively with RGS8 mRNA. This interaction was impaired when ATXN2 harbored an expanded polyglutamine. Mutant ATXN2 also reduced RGS8 expression in an in vitro coupled translation assay when compared with equal expression of wild-type ATXN2-Q22. Reduced abundance of Rgs8 in Pcp2-ATXN2[Q127] and BAC-Q72 mice supports our observations of a hyper-excitable mGluR1-ITPR1 signaling axis in SCA2, as RGS proteins are linked to attenuating mGluR1 signaling. Public Library of Science 2015-04-22 /pmc/articles/PMC4406435/ /pubmed/25902068 http://dx.doi.org/10.1371/journal.pgen.1005182 Text en © 2015 Dansithong 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 Dansithong, Warunee Paul, Sharan Figueroa, Karla P. Rinehart, Marc D. Wiest, Shaina Pflieger, Lance T. Scoles, Daniel R. Pulst, Stefan M. Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model |
title | Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model |
title_full | Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model |
title_fullStr | Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model |
title_full_unstemmed | Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model |
title_short | Ataxin-2 Regulates RGS8 Translation in a New BAC-SCA2 Transgenic Mouse Model |
title_sort | ataxin-2 regulates rgs8 translation in a new bac-sca2 transgenic mouse model |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4406435/ https://www.ncbi.nlm.nih.gov/pubmed/25902068 http://dx.doi.org/10.1371/journal.pgen.1005182 |
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