FOX-2 Dependent Splicing of Ataxin-2 Transcript Is Affected by Ataxin-1 Overexpression

Alternative splicing is a fundamental posttranscriptional mechanism for controlling gene expression, and splicing defects have been linked to various human disorders. The splicing factor FOX-2 is part of a main protein interaction hub in a network related to human inherited ataxias, however, its impact remains to be elucidated. Here, we focused on the reported interaction between FOX-2 and ataxin-1, the disease-causing protein in spinocerebellar ataxia type 1. In this line, we further evaluated this interaction by yeast-2-hybrid analyses and co-immunoprecipitation experiments in mammalian cells. Interestingly, we discovered that FOX-2 localization and splicing activity is affected in the presence of nuclear ataxin-1 inclusions. Moreover, we observed that FOX-2 directly interacts with ataxin-2, a protein modulating spinocerebellar ataxia type 1 pathogenesis. Finally, we provide evidence that splicing of pre-mRNA of ataxin-2 depends on FOX-2 activity, since reduction of FOX-2 levels led to increased skipping of exon 18 in ataxin-2 transcripts. Most striking, we observed that ataxin-1 overexpression has an effect on this splicing event as well. Thus, our results demonstrate that FOX-2 is involved in splicing of ataxin-2 transcripts and that this splicing event is altered by overexpression of ataxin-1.

[1]  A. Barabasi,et al.  A Protein–Protein Interaction Network for Human Inherited Ataxias and Disorders of Purkinje Cell Degeneration , 2006, Cell.

[2]  B. Blencowe.  Alternative Splicing: New Insights from Global Analyses , 2006, Cell.

[3]  D. Black,et al.  An inducible change in Fox-1/A2BP1 splicing modulates the alternative splicing of downstream neuronal target exons. , 2009, Genes & development.

[4]  S. Pulst,et al.  A novel protein with RNA-binding motifs interacts with ataxin-2. , 2000, Human molecular genetics.

[5]  Kai-Wei Chang,et al.  RNA-binding proteins in human genetic disease. , 2008, Trends in genetics : TIG.

[6]  Harry T Orr,et al.  Ataxin-1 Nuclear Localization and Aggregation Role in Polyglutamine-Induced Disease in SCA1 Transgenic Mice , 1998, Cell.

[7]  R. Montiel,et al.  Increased transcript diversity: novel splicing variants of Machado–Joseph Disease gene (ATXN3) , 2010, neurogenetics.

[8]  Eric T. Wang,et al.  Alternative Isoform Regulation in Human Tissue Transcriptomes , 2008, Nature.

[9]  H. Paulson,et al.  Splice Isoforms of the Polyglutamine Disease Protein Ataxin-3 Exhibit Similar Enzymatic yet Different Aggregation Properties , 2010, PloS one.

[10]  B. Graveley.  Alternative splicing: increasing diversity in the proteomic world. , 2001, Trends in genetics : TIG.

[11]  R. Guigó,et al.  Are splicing mutations the most frequent cause of hereditary disease? , 2005, FEBS letters.

[12]  Seongman Kang,et al.  Molecular pathogenesis of spinocerebellar ataxia type 1 disease , 2009, Molecules and cells.

[13]  Yadong Wang,et al.  Constructing disease-specific gene networks using pair-wise relevance metric: Application to colon cancer identifies interleukin 8, desmin and enolase 1 as the central elements , 2008, BMC Systems Biology.

[14]  L. Raymond,et al.  Canadian Association of Neurosciences Review: Polyglutamine Expansion Neurodegenerative Diseases , 2006, Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques.

[15]  V. Moskvina,et al.  Genetic utility of broadly defined bipolar schizoaffective disorder as a diagnostic concept , 2009, British Journal of Psychiatry.

[16]  H. Lehrach,et al.  The KRAB-containing zinc-finger transcriptional regulator ZBRK1 activates SCA2 gene transcription through direct interaction with its gene product, ataxin-2. , 2011, Human molecular genetics.

[17]  Atif A Ahmed,et al.  Complex Congenital Heart Defects in Association with Maternal Diabetes and Partial Deletion of the A2BP1 Gene , 2011, Fetal and pediatric pathology.

[18]  H. Zoghbi,et al.  The spinocerebellar ataxia type 1 protein, ataxin-1, has RNA-binding activity that is inversely affected by the length of its polyglutamine tract. , 2001, Human molecular genetics.

[19]  D. Housman,et al.  The complex pathology of trinucleotide repeats. , 1997, Current opinion in cell biology.

[20]  H. Kuroyanagi.  Fox-1 family of RNA-binding proteins , 2009, Cellular and Molecular Life Sciences.

[21]  Michael Q. Zhang,et al.  Defining the regulatory network of the tissue-specific splicing factors Fox-1 and Fox-2. , 2008, Genes & development.

[22]  L. Dember,et al.  Individual RNA Recognition Motifs of TIA-1 and TIAR Have Different RNA Binding Specificities (*) , 1996, The Journal of Biological Chemistry.

[23]  H. Zoghbi,et al.  Identification of genes that modify ataxin-1-induced neurodegeneration , 2000, Nature.

[24]  Toby J. Gibson,et al.  Phosphorylation of S776 and 14-3-3 Binding Modulate Ataxin-1 Interaction with Splicing Factors , 2009, PloS one.

[25]  Ying-Hui Fu,et al.  A novel central nervous system-enriched spinocerebellar ataxia type 7 gene product. , 2003, Archives of neurology.

[26]  A. Pastore,et al.  Polyglutamine is not all: the functional role of the AXH domain in the ataxin-1 protein. , 2005, Journal of molecular biology.

[27]  U. Rüb,et al.  Spinocerebellar ataxia 2 (SCA2) , 2008, The Cerebellum.

[28]  Paola Giunti,et al.  Clinical, genetic, molecular, and pathophysiological insights into spinocerebellar ataxia type 1 , 2008, The Cerebellum.

[29]  Harry T Orr,et al.  RNA association and nucleocytoplasmic shuttling by ataxin-1 , 2005, Journal of Cell Science.

[30]  Masahiko Watanabe,et al.  Machado–Joseph disease gene products carrying different carboxyl termini , 1997, Neuroscience Research.

[31]  Thomas Lengauer,et al.  An integrative approach to gain insights into the cellular function of human ataxin-2. , 2005, Journal of molecular biology.

[32]  J. Stévenin,et al.  TIA-1 and TIAR Activate Splicing of Alternative Exons with Weak 5′ Splice Sites followed by a U-rich Stretch on Their Own Pre-mRNAs* , 2001, The Journal of Biological Chemistry.

[33]  Huda Y. Zoghbi,et al.  Expansion of an unstable trinucleotide CAG repeat in spinocerebellar ataxia type 1 , 1993, Nature Genetics.

[34]  Christa Lese Martin,et al.  Cytogenetic and molecular characterization of A2BP1/FOX1 as a candidate gene for autism , 2007, American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics.

[35]  Wei Li,et al.  RNA-Binding Proteins Tia-1 and Tiar Link the Phosphorylation of Eif-2α to the Assembly of Mammalian Stress Granules , 1999, The Journal of cell biology.

[36]  Peter Stoilov,et al.  Homologues of the Caenorhabditis elegans Fox-1 Protein Are Neuronal Splicing Regulators in Mammals , 2005, Molecular and Cellular Biology.

[37]  T. Cristofaro,et al.  Identification of alternative splicing of spinocerebellar ataxia type 2 gene. , 2001, Gene.

[38]  Taesoo Kim,et al.  Polyglutamine-expanded ataxin-1 recruits Cu/Zn-superoxide dismutase into the nucleus of HeLa cells. , 2003, Biochemical and biophysical research communications.

[39]  S. Pulst,et al.  dAtaxin-2 Mediates Expanded Ataxin-1-Induced Neurodegeneration in a Drosophila Model of SCA1 , 2007, PLoS genetics.

[40]  L. Ukani,et al.  Comparative analysis of genetic modifiers in Drosophila points to common and distinct mechanisms of pathogenesis among polyglutamine diseases. , 2008, Human molecular genetics.

[41]  F. Müller,et al.  Splicing Segregation: The Minor Spliceosome Acts outside the Nucleus and Controls Cell Proliferation , 2007, Cell.

[42]  Janghoo Lim,et al.  Opposing effects of polyglutamine expansion on native protein complexes contribute to SCA1 , 2008, Nature.

[43]  S. Kawamoto,et al.  Tissue-dependent isoforms of mammalian Fox-1 homologs are associated with tissue-specific splicing activities , 2005, Nucleic acids research.

[44]  Harry T. Orr,et al.  Identification and characterization of the gene causing type 1 spinocerebellar ataxia , 1994, Nature Genetics.

[45]  A. Krainer,et al.  Regulation of alternative splicing in vivo by overexpression of antagonistic splicing factors. , 1994, Science.

[46]  M. Mann,et al.  A comprehensive biochemical and genetic analysis of the yeast U1 snRNP reveals five novel proteins. , 1998, RNA.

[47]  Hung-Ying Kao,et al.  Ataxin 1, a SCA1 neurodegenerative disorder protein, is functionally linked to the silencing mediator of retinoid and thyroid hormone receptors , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[48]  V. Kruys,et al.  The splicing factor ASF/SF2 is associated with TIA‐1‐related/TIA‐1‐containing ribonucleoproteic complexes and contributes to post‐transcriptional repression of gene expression , 2010, The FEBS journal.

[49]  K. Swoboda,et al.  Escaping the Nuclear Confines: Signal-Dependent Pre-mRNA Splicing in Anucleate Platelets , 2005, Cell.

[50]  P. Anderson,et al.  RNA granules , 2006, The Journal of cell biology.

[51]  Michael Sattler,et al.  U2AF-homology motif interactions are required for alternative splicing regulation by SPF45 , 2007, Nature Structural &Molecular Biology.

[52]  S. Pulst,et al.  Genomic structure of the human gene for spinocerebellar ataxia type 2 (SCA2) on chromosome 12q24.1. , 1998, Genomics.

[53]  A. F. Neuwald,et al.  Ataxin-2, global regulators and bacterial gene expression, and spliceosomal snRNP proteins share a conserved domain , 1997, Journal of Molecular Medicine.

[54]  Christel Rouget,et al.  Xenopus Rbm9 is a novel interactor of XGld2 in the cytoplasmic polyadenylation complex , 2008, The FEBS journal.

[55]  Guey-Shin Wang,et al.  Splicing in disease: disruption of the splicing code and the decoding machinery , 2007, Nature Reviews Genetics.

[56]  Thomas Lengauer,et al.  Ataxin-2 and huntingtin interact with endophilin-A complexes to function in plastin-associated pathways. , 2005, Human molecular genetics.

[57]  Christina Thaller,et al.  miR-19, miR-101 and miR-130 co-regulate ATXN1 levels to potentially modulate SCA1 pathogenesis , 2008, Nature Neuroscience.

[58]  H. Zoghbi,et al.  Ataxin-1 with an expanded glutamine tract alters nuclear matrix-associated structures , 1997, Nature.

[59]  H. Lehrach,et al.  Ataxin-2 interacts with the DEAD/H-box RNA helicase DDX6 and interferes with P-bodies and stress granules. , 2007, Molecular biology of the cell.

[60]  Robert Walgate,et al.  Proliferation , 1985, Nature.

[61]  Harry T Orr,et al.  Pathogenic Mechanisms of a Polyglutamine-mediated Neurodegenerative Disease, Spinocerebellar Ataxia Type 1* , 2009, Journal of Biological Chemistry.

[62]  C Jodice,et al.  The AXH module: an independently folded domain common to ataxin‐1 and HBP1 , 2003, FEBS letters.

[63]  H. Mizusawa,et al.  Cell-type-specific alternative splicing in spinocerebellar ataxia type 6 , 2008, Neuroscience Letters.

[64]  A. Varadaraj,et al.  Ataxin-1 Fusion Partners Alter PolyQ Lethality and Aggregation , 2007, PloS one.

[65]  Gene W. Yeo,et al.  An RNA code for the FOX2 splicing regulator revealed by mapping RNA-protein interactions in stem cells , 2009, Nature Structural &Molecular Biology.

[66]  H. Zoghbi,et al.  Glutamine repeats and neurodegeneration. , 2000, Annual review of neuroscience.

[67]  Mitsuo Kato,et al.  Cell type and culture condition-dependent alternative splicing in human breast cancer cells revealed by splicing-sensitive microarrays. , 2006, Cancer research.