1
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Sung HM, Schott J, Boss P, Lehmann JA, Hardt MR, Lindner D, Messens J, Bogeski I, Ohler U, Stoecklin G. Stress-induced nuclear speckle reorganization is linked to activation of immediate early gene splicing. J Cell Biol 2023; 222:e202111151. [PMID: 37956386 PMCID: PMC10641589 DOI: 10.1083/jcb.202111151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 07/13/2023] [Accepted: 09/29/2023] [Indexed: 11/15/2023] Open
Abstract
Current models posit that nuclear speckles (NSs) serve as reservoirs of splicing factors and facilitate posttranscriptional mRNA processing. Here, we discovered that ribotoxic stress induces a profound reorganization of NSs with enhanced recruitment of factors required for splice-site recognition, including the RNA-binding protein TIAR, U1 snRNP proteins and U2-associated factor 65, as well as serine 2 phosphorylated RNA polymerase II. NS reorganization relies on the stress-activated p38 mitogen-activated protein kinase (MAPK) pathway and coincides with splicing activation of both pre-existing and newly synthesized pre-mRNAs. In particular, ribotoxic stress causes targeted excision of retained introns from pre-mRNAs of immediate early genes (IEGs), whose transcription is induced during the stress response. Importantly, enhanced splicing of the IEGs ZFP36 and FOS is accompanied by relocalization of the corresponding nuclear mRNA foci to NSs. Our study reveals NSs as a dynamic compartment that is remodeled under stress conditions, whereby NSs appear to become sites of IEG transcription and efficient cotranscriptional splicing.
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Affiliation(s)
- Hsu-Min Sung
- Mannheim Institute for Innate Immunoscience (MI3) and Mannheim Cancer Center (MCC), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ)-ZMBH Alliance, Heidelberg, Germany
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
- Brussels Center for Redox Biology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Johanna Schott
- Mannheim Institute for Innate Immunoscience (MI3) and Mannheim Cancer Center (MCC), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ)-ZMBH Alliance, Heidelberg, Germany
| | - Philipp Boss
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
- Department of Biology, Humboldt University, Berlin, Germany
| | - Janina A. Lehmann
- Mannheim Institute for Innate Immunoscience (MI3) and Mannheim Cancer Center (MCC), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ)-ZMBH Alliance, Heidelberg, Germany
| | - Marius Roland Hardt
- Mannheim Institute for Innate Immunoscience (MI3) and Mannheim Cancer Center (MCC), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ)-ZMBH Alliance, Heidelberg, Germany
| | - Doris Lindner
- Mannheim Institute for Innate Immunoscience (MI3) and Mannheim Cancer Center (MCC), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ)-ZMBH Alliance, Heidelberg, Germany
| | - Joris Messens
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
- Brussels Center for Redox Biology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Ivan Bogeski
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Uwe Ohler
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
- Department of Biology, Humboldt University, Berlin, Germany
| | - Georg Stoecklin
- Mannheim Institute for Innate Immunoscience (MI3) and Mannheim Cancer Center (MCC), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University (ZMBH), German Cancer Research Center (DKFZ)-ZMBH Alliance, Heidelberg, Germany
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2
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Zaman M, Fu Y, Chen PC, Sun H, Yang S, Wu Z, Wang Z, Poudel S, Serrano GE, Beach TG, Li L, Wang X, Peng J. Dissecting Detergent-Insoluble Proteome in Alzheimer's Disease by TMTc-Corrected Quantitative Mass Spectrometry. Mol Cell Proteomics 2023; 22:100608. [PMID: 37356496 PMCID: PMC10392608 DOI: 10.1016/j.mcpro.2023.100608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 06/16/2023] [Accepted: 06/21/2023] [Indexed: 06/27/2023] Open
Abstract
Protein aggregation of amyloid-β peptides and tau are pathological hallmarks of Alzheimer's disease (AD), which are often resistant to detergent extraction and thus enriched in the insoluble proteome. However, additional proteins that coaccumulate in the detergent-insoluble AD brain proteome remain understudied. Here, we comprehensively characterized key proteins and pathways in the detergent-insoluble proteome from human AD brain samples using differential extraction, tandem mass tag (TMT) labeling, and two-dimensional LC-tandem mass spectrometry. To improve quantification accuracy of the TMT method, we developed a complement TMT-based strategy to correct for ratio compression. Through the meta-analysis of two independent detergent-insoluble AD proteome datasets (8914 and 8917 proteins), we identified 190 differentially expressed proteins in AD compared with control brains, highlighting the pathways of amyloid cascade, RNA splicing, endocytosis/exocytosis, protein degradation, and synaptic activity. To differentiate the truly detergent-insoluble proteins from copurified background during protein extraction, we analyzed the fold of enrichment for each protein by comparing the detergent-insoluble proteome with the whole proteome from the same AD samples. Among the 190 differentially expressed proteins, 84 (51%) proteins of the upregulated proteins (n = 165) were enriched in the insoluble proteome, whereas all downregulated proteins (n = 25) were not enriched, indicating that they were copurified components. The vast majority of these enriched 84 proteins harbor low-complexity regions in their sequences, including amyloid-β, Tau, TARDBP/TAR DNA-binding protein 43, SNRNP70/U1-70K, MDK, PTN, NTN1, NTN3, and SMOC1. Moreover, many of the enriched proteins in AD were validated in the detergent-insoluble proteome by five steps of differential extraction, proteomic analysis, or immunoblotting. Our study reveals a resource list of proteins and pathways that are exclusively present in the detergent-insoluble proteome, providing novel molecular insights to the formation of protein pathology in AD.
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Affiliation(s)
- Masihuz Zaman
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Yingxue Fu
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Ping-Chung Chen
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Huan Sun
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Shu Yang
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Zhiping Wu
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Zhen Wang
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Suresh Poudel
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Geidy E Serrano
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Thomas G Beach
- Banner Sun Health Research Institute, Sun City, Arizona, USA
| | - Ling Li
- Department of Biology, University of North Dakota, Grand Forks, North Dakota, USA
| | - Xusheng Wang
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
| | - Junmin Peng
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Department of Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, Tennessee, USA; Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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3
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Feng Q, Lin Z, Deng Y, Ran Y, Yu R, Xiang AP, Ye C, Yao C. The U1 antisense morpholino oligonucleotide (AMO) disrupts U1 snRNP structure to promote intronic PCPA modification of pre-mRNAs. J Biol Chem 2023; 299:104854. [PMID: 37224962 PMCID: PMC10404622 DOI: 10.1016/j.jbc.2023.104854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/12/2023] [Accepted: 05/13/2023] [Indexed: 05/26/2023] Open
Abstract
Functional depletion of the U1 small nuclear ribonucleoprotein (snRNP) with a 25 nt U1 AMO (antisense morpholino oligonucleotide) may lead to intronic premature cleavage and polyadenylation of thousands of genes, a phenomenon known as U1 snRNP telescripting; however, the underlying mechanism remains elusive. In this study, we demonstrated that U1 AMO could disrupt U1 snRNP structure both in vitro and in vivo, thereby affecting the U1 snRNP-RNAP polymerase II interaction. By performing chromatin immunoprecipitation sequencing for phosphorylation of Ser2 and Ser5 of the C-terminal domain of RPB1, the largest subunit of RNAP polymerase II, we showed that transcription elongation was disturbed upon U1 AMO treatment, with a particular high phosphorylation of Ser2 signal at intronic cryptic polyadenylation sites (PASs). In addition, we showed that core 3'processing factors CPSF/CstF are involved in the processing of intronic cryptic PAS. Their recruitment accumulated toward cryptic PASs upon U1 AMO treatment, as indicated by chromatin immunoprecipitation sequencing and individual-nucleotide resolution CrossLinking and ImmunoPrecipitation sequencing analysis. Conclusively, our data suggest that disruption of U1 snRNP structure mediated by U1 AMO provides a key for understanding the U1 telescripting mechanism.
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Affiliation(s)
- Qiumin Feng
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Zejin Lin
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Yanhui Deng
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yi Ran
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Rui Yu
- Department of Biochemistry, School of Medicine, Ningbo University, Ningbo, Zhejiang, China
| | - Andy Peng Xiang
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Congting Ye
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China.
| | - Chengguo Yao
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China; Advanced Medical Technology Center, The first Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China; Department of Genetics and Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China.
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4
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Mimoso CA, Adelman K. U1 snRNP increases RNA Pol II elongation rate to enable synthesis of long genes. Mol Cell 2023; 83:1264-1279.e10. [PMID: 36965480 PMCID: PMC10135401 DOI: 10.1016/j.molcel.2023.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/06/2023] [Accepted: 02/28/2023] [Indexed: 03/27/2023]
Abstract
The expansion of introns within mammalian genomes poses a challenge for the production of full-length messenger RNAs (mRNAs), with increasing evidence that these long AT-rich sequences present obstacles to transcription. Here, we investigate RNA polymerase II (RNAPII) elongation at high resolution in mammalian cells and demonstrate that RNAPII transcribes faster across introns. Moreover, we find that this acceleration requires the association of U1 snRNP (U1) with the elongation complex at 5' splice sites. The role of U1 to stimulate elongation rate through introns reduces the frequency of both premature termination and transcriptional arrest, thereby dramatically increasing RNA production. We further show that changes in RNAPII elongation rate due to AT content and U1 binding explain previous reports of pausing or termination at splice junctions and the edge of CpG islands. We propose that U1-mediated acceleration of elongation has evolved to mitigate the risks that long AT-rich introns pose to transcript completion.
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Affiliation(s)
- Claudia A Mimoso
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Karen Adelman
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA; Ludwig Center at Harvard, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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5
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Stepien A, Dolata J, Gulanicz T, Bielewicz D, Bajczyk M, Smolinski DJ, Szweykowska-Kulinska Z, Jarmolowski A. Chromatin-associated microprocessor assembly is regulated by the U1 snRNP auxiliary protein PRP40. Plant Cell 2022; 34:4920-4935. [PMID: 36087009 PMCID: PMC9709975 DOI: 10.1093/plcell/koac278] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 09/05/2022] [Indexed: 06/01/2023]
Abstract
In plants, microRNA (miRNA) biogenesis involves cotranscriptional processing of RNA polymerase II (RNAPII)-generated primary transcripts by a multi-protein complex termed the microprocessor. Here, we report that Arabidopsis (Arabidopsis thaliana) PRE-MRNA PROCESSING PROTEIN 40 (PRP40), the U1 snRNP auxiliary protein, positively regulates the recruitment of SERRATE, a core component of the plant microprocessor, to miRNA genes. The association of DICER-LIKE1 (DCL1), the microprocessor endoribonuclease, with chromatin was altered in prp40ab mutant plants. Impaired cotranscriptional microprocessor assembly was accompanied by RNAPII accumulation at miRNA genes and retention of miRNA precursors at their transcription sites in the prp40ab mutant plants. We show that cotranscriptional microprocessor assembly, regulated by AtPRP40, positively affects RNAPII transcription of miRNA genes and is important to reach the correct levels of produced miRNAs.
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Affiliation(s)
| | | | | | | | - Mateusz Bajczyk
- Department of Gene Expression, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan 61-614, Poland
| | - Dariusz J Smolinski
- Department of Cellular and Molecular Biology, Nicolaus Copernicus University, Torun 87-100, Poland
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Torun 87-100, Poland
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6
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Lee ES, Smith HW, Wolf EJ, Guvenek A, Wang YE, Emili A, Tian B, Palazzo AF. ZFC3H1 and U1-70K promote the nuclear retention of mRNAs with 5' splice site motifs within nuclear speckles. RNA 2022; 28:878-894. [PMID: 35351812 PMCID: PMC9074902 DOI: 10.1261/rna.079104.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 03/12/2022] [Indexed: 05/22/2023]
Abstract
Quality control of mRNA represents an important regulatory mechanism for gene expression in eukaryotes. One component of this quality control is the nuclear retention and decay of misprocessed RNAs. Previously, we demonstrated that mature mRNAs containing a 5' splice site (5'SS) motif, which is typically found in misprocessed RNAs such as intronic polyadenylated (IPA) transcripts, are nuclear retained and degraded. Using high-throughput sequencing of cellular fractions, we now demonstrate that IPA transcripts require the zinc finger protein ZFC3H1 for their nuclear retention and degradation. Using reporter mRNAs, we demonstrate that ZFC3H1 promotes the nuclear retention of mRNAs with intact 5'SS motifs by sequestering them into nuclear speckles. Furthermore, we find that U1-70K, a component of the spliceosomal U1 snRNP, is also required for the nuclear retention of these reporter mRNAs and likely functions in the same pathway as ZFC3H1. Finally, we show that the disassembly of nuclear speckles impairs the nuclear retention of reporter mRNAs with 5'SS motifs. Our results highlight a splicing independent role of U1 snRNP and indicate that it works in conjunction with ZFC3H1 in preventing the nuclear export of misprocessed mRNAs by sequestering them into nuclear speckles.
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Affiliation(s)
- Eliza S Lee
- Department of Biochemistry, University of Toronto, Ontario M5S 1A8, Canada
| | - Harrison W Smith
- Department of Biochemistry, University of Toronto, Ontario M5S 1A8, Canada
| | - Eric J Wolf
- Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
| | - Aysegul Guvenek
- Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA
| | - Yifan E Wang
- Department of Biochemistry, University of Toronto, Ontario M5S 1A8, Canada
| | - Andrew Emili
- Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Bin Tian
- Rutgers New Jersey Medical School, Newark, New Jersey 07103, USA
- Wistar Institute, Philadelphia, Pennsylvania 19104, USA
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7
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Zhang X, Yang D, Yang X, Zhang X, Zhang Y, Huang Y, Zhang S, Liu Z. U1 small nuclear ribonucleoprotein is essential for early larval development in silkworm, Bombyx mori. Insect Sci 2022; 29:379-387. [PMID: 34231971 DOI: 10.1111/1744-7917.12946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/04/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
U1 small nuclear ribonucleoproteins (U1 snRNP) associates with 5' splice sites in the form of ribonucleoprotein particles and is highly conserved among species. The physiological functions of U1 snRNP in a lepidopteran model insect Bombyx mori is mostly unknown. Here, we showed that U1 snRNP plays an important role in the development of silkworm. Knockout of U1 snRNP in silkworm showed either delayed or stationary 1st instar larva development compared with the wild-type group. U1 snRNP deletion mutants exhibited abnormal cellular phenotypes with enlarged cell nucleus, scant cytoplasm and enlarged nuclei. RNA-seq analysis revealed that genes involved in metabolic pathway, biosynthesis of secondary metabolites and steroid hormone biosynthesis were significantly affected by U1 snRNP depletion. Taken together, our study suggests that U1 snRNP homeostasis plays an important role in silkworm development.
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Affiliation(s)
- Xiaoqian Zhang
- College Forestry, Shangdong Agriculture University, Shangdong Province, Taian, China
| | - Dehong Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xu Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xinran Zhang
- College Forestry, Shangdong Agriculture University, Shangdong Province, Taian, China
| | - Yong Zhang
- Soochow University, Suzhou, Jiangsu Province, China
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Shengxiang Zhang
- College Forestry, Shangdong Agriculture University, Shangdong Province, Taian, China
| | - Zulian Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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8
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Chang P, Hsieh HY, Tu SL. The U1 snRNP component RBP45d regulates temperature-responsive flowering in Arabidopsis. Plant Cell 2022; 34:834-851. [PMID: 34791475 PMCID: PMC8824692 DOI: 10.1093/plcell/koab273] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/01/2021] [Indexed: 05/26/2023]
Abstract
Precursor messenger RNA (Pre-mRNA) splicing is a crucial step in gene expression whereby the spliceosome produces constitutively and alternatively spliced transcripts. These transcripts not only diversify the transcriptome, but also play essential roles in plant development and responses to environmental changes. Much evidence indicates that regulation at the pre-mRNA splicing step is important for flowering time control; however, the components and detailed mechanism underlying this process remain largely unknown. Here, we identified the splicing factor RNA BINDING PROTEIN 45d (RBP45d), a member of the RBP45/47 family in Arabidopsis thaliana. Using sequence comparison and biochemical analysis, we determined that RBP45d is a component of the U1 small nuclear ribonucleoprotein (U1 snRNP) with functions distinct from other family members. RBP45d associates with the U1 snRNP by interacting with pre-mRNA-processing factor 39a (PRP39a) and directly regulates alternative splicing (AS) for a specific set of genes. Plants with loss of RBP45d and PRP39a function exhibited defects in temperature-induced flowering, potentially due to the misregulation of temperature-sensitive AS of FLOWERING LOCUS M as well as the accumulation of the flowering repressor FLOWERING LOCUS C. Taken together, RBP45d is a U1 snRNP component in plants that functions with PRP39a in temperature-mediated flowering.
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Affiliation(s)
- Ping Chang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
- Molecular and Biological Agricultural Science, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei 11529, Taiwan
- Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 40227, Taiwan
| | - Hsin-Yu Hsieh
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Shih-Long Tu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
- Molecular and Biological Agricultural Science, Taiwan International Graduate Program, National Chung-Hsing University and Academia Sinica, Taipei 11529, Taiwan
- Biotechnology Center, National Chung-Hsing University, Taichung 40227, Taiwan
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9
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Jobbins AM, Campagne S, Weinmeister R, Lucas CM, Gosliga AR, Clery A, Chen L, Eperon LP, Hodson MJ, Hudson AJ, Allain FHT, Eperon IC. Exon-independent recruitment of SRSF1 is mediated by U1 snRNP stem-loop 3. EMBO J 2022; 41:e107640. [PMID: 34779515 PMCID: PMC8724738 DOI: 10.15252/embj.2021107640] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 12/11/2022] Open
Abstract
SRSF1 protein and U1 snRNPs are closely connected splicing factors. They both stimulate exon inclusion, SRSF1 by binding to exonic splicing enhancer sequences (ESEs) and U1 snRNPs by binding to the downstream 5' splice site (SS), and both factors affect 5' SS selection. The binding of U1 snRNPs initiates spliceosome assembly, but SR proteins such as SRSF1 can in some cases substitute for it. The mechanistic basis of this relationship is poorly understood. We show here by single-molecule methods that a single molecule of SRSF1 can be recruited by a U1 snRNP. This reaction is independent of exon sequences and separate from the U1-independent process of binding to an ESE. Structural analysis and cross-linking data show that SRSF1 contacts U1 snRNA stem-loop 3, which is required for splicing. We suggest that the recruitment of SRSF1 to a U1 snRNP at a 5'SS is the basis for exon definition by U1 snRNP and might be one of the principal functions of U1 snRNPs in the core reactions of splicing in mammals.
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Affiliation(s)
- Andrew M Jobbins
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Present address:
MRC London Institute of Medical SciencesLondonUK
- Present address:
Institute of Clinical SciencesImperial College LondonLondonUK
| | - Sébastien Campagne
- Institute of BiochemistryETH ZürichSwitzerland
- Present address:
Inserm U1212CNRS UMR5320ARNA LaboratoryBordeaux CedexFrance
| | - Robert Weinmeister
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Leicester Institute of Structural & Chemical Biology and Department of ChemistryUniversity of LeicesterLeicesterUK
| | - Christian M Lucas
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Alison R Gosliga
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
- Present address:
Institut für Industrielle GenetikAbt.(eilung) SystembiologieUniversität StuttgartStuttgartGermany
| | | | - Li Chen
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Lucy P Eperon
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Mark J Hodson
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
| | - Andrew J Hudson
- Leicester Institute of Structural & Chemical Biology and Department of ChemistryUniversity of LeicesterLeicesterUK
| | | | - Ian C Eperon
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell BiologyUniversity of LeicesterLeicesterUK
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10
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Rosenbach H, Span I. Obtaining Crystals of Nucleic Acids in Complex with the Protein U1A Using the Soaking Method. Methods Mol Biol 2022; 2439:105-115. [PMID: 35226318 DOI: 10.1007/978-1-0716-2047-2_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
X-ray crystallography is one of the most prominent techniques for determining high-resolution structures of nucleic acids. The major challenges are to obtain well-diffracting single crystals and to solve the phase problem. The absence of structural information impedes the elucidation of the molecular details of biological processes. A particularly intriguing example is the RNA-cleavage catalyzed by the 10-23 deoxyribozyme (DNAzyme). This DNAzyme consists of a catalytic core that is flanked by two substrate binding arms, which can be designed to bind any RNA of interest. Structure elucidation of the 10-23 DNAzyme in a biologically relevant conformation faces three major challenges: (1) stabilization of the RNA substrate to capture the DNA:RNA complex in the pre-catalytic conformation, (2) prevention of the formation of an artificial duplex conformation due to a self-complementary sequence in the catalytic core of the DNAzyme, and (3) the crystallization of nucleic acids with their uniform surfaces. Here, we provide a protocol for an innovative strategy facilitating the crystallization of protein:nucleic acid complexes using a soaking approach and discuss on how to apply this protocol for the structure elucidation of the 10-23 DNAzyme. For this purpose, we describe the purification procedure of an optimized variant of the RNA-binding protein U1A, the crystallization of this specific U1A variant, the soaking process with its specific RNA hairpin loop, and finally suggest a strategy for applying this procedure on the 10-23 DNAzyme in complex with its specific RNA target.
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Affiliation(s)
- Hannah Rosenbach
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Ingrid Span
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
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11
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Voss PG, Haudek KC, Patterson RJ, Wang JL. Galectin-3-U1 snRNP Complexes Initiate Splicing Activity in U1-Depleted Nuclear Extracts. Methods Mol Biol 2022; 2442:713-726. [PMID: 35320554 DOI: 10.1007/978-1-0716-2055-7_38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Fractionation of HeLa cell nuclear extracts by glycerol gradient centrifugation separates endogenous uracil-rich small nuclear ribonucleoprotein complexes (U snRNP) into numerous particles sedimenting from 7S to greater than 60S. Complexes sedimenting at 10S contain a single U snRNP (U1 snRNP) and galectin-3. Addition of antibodies specific for galectin-3 to fractions containing these 10S complexes coprecipitates U1 snRNP, indicating that a fraction of the U1 snRNP is associated with this galectin. Galectin-3 has been shown by depletion-reconstitution studies to be an integral splicing component involved both in spliceosome assembly and splicing activity. The first step in initiation of spliceosome assembly is binding of U1 snRNP to the 5' splice site of the premessenger RNA substrate. The finding that U1 snRNP and galectin-3 are associated in splicing extracts hints that this complex affords a potential entry point for galectin-3 into the splicing pathway. Addition of U1 snRNP-galectin-3 complexes immunoselected from the 10S region of glycerol gradients to a U1-depleted nuclear extract initiates splicing activity with the formation of splicing intermediates and mature mRNA. This chapter describes the materials and methods for these experiments that document galectin-3-U1 snRNP complexes initiate the splicing reaction in a U1-depleted nuclear extract.
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Affiliation(s)
- Patricia G Voss
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Kevin C Haudek
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Ronald J Patterson
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - John L Wang
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA.
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12
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Campagne S, de Vries T, Allain FHT. Probing the Interactions of Splicing Regulatory Small Molecules and Proteins with U1 snRNP Using NMR Spectroscopy. Methods Mol Biol 2022; 2537:247-262. [PMID: 35895269 DOI: 10.1007/978-1-0716-2521-7_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Alternative RNA splicing is an essential part of gene expression that not only increases the protein diversity of metazoan but also provides an additional layer of gene expression regulation. The U1 small ribonucleoparticle (U1 snRNP) plays an essential role in seeding spliceosome assembly and its binding on weak 5'-splice sites is regulated by transient interactions with splicing factors. Recent progress in allele specific splicing correction has shown the therapeutic potential offered by small molecule splicing modifiers that specifically promotes the recruitment of U1 snRNP to modulate alternative splicing and gene expression. Here, we described a method to reconstitute U1 snRNP in vitro and to study labile interactions with protein or synthetic splicing factors using solution state NMR spectroscopy. This approach allowed us to validate direct interactions between splicing regulators and U1 snRNP and could also be useful for the screening of small molecules acting on splicing regulation.
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Affiliation(s)
- Sébastien Campagne
- ARNA Laboratory, INSERM U1212, CNRS 5320, University of Bordeaux, Bordeaux, France.
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland.
| | - Tebbe de Vries
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Frédéric H-T Allain
- Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland.
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13
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Borao S, Ayté J, Hümmer S. Evolution of the Early Spliceosomal Complex-From Constitutive to Regulated Splicing. Int J Mol Sci 2021; 22:ijms222212444. [PMID: 34830325 PMCID: PMC8624252 DOI: 10.3390/ijms222212444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/14/2022] Open
Abstract
Pre-mRNA splicing is a major process in the regulated expression of genes in eukaryotes, and alternative splicing is used to generate different proteins from the same coding gene. Splicing is a catalytic process that removes introns and ligates exons to create the RNA sequence that codifies the final protein. While this is achieved in an autocatalytic process in ancestral group II introns in prokaryotes, the spliceosome has evolved during eukaryogenesis to assist in this process and to finally provide the opportunity for intron-specific splicing. In the early stage of splicing, the RNA 5' and 3' splice sites must be brought within proximity to correctly assemble the active spliceosome and perform the excision and ligation reactions. The assembly of this first complex, termed E-complex, is currently the least understood process. We focused in this review on the formation of the E-complex and compared its composition and function in three different organisms. We highlight the common ancestral mechanisms in S. cerevisiae, S. pombe, and mammals and conclude with a unifying model for intron definition in constitutive and regulated co-transcriptional splicing.
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Affiliation(s)
- Sonia Borao
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, 08003 Barcelona, Spain;
| | - José Ayté
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, 08003 Barcelona, Spain;
- Correspondence: (J.A.); (S.H.)
| | - Stefan Hümmer
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, 08003 Barcelona, Spain;
- Translational Molecular Pathology, Vall d’Hebron Research Institute (VHIR), CIBERONC, 08035 Barcelona, Spain
- Correspondence: (J.A.); (S.H.)
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14
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Kundinger SR, Dammer EB, Yin L, Hurst C, Shapley S, Ping L, Khoshnevis S, Ghalei H, Duong DM, Seyfried NT. Phosphorylation regulates arginine-rich RNA-binding protein solubility and oligomerization. J Biol Chem 2021; 297:101306. [PMID: 34673031 PMCID: PMC8569591 DOI: 10.1016/j.jbc.2021.101306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 12/16/2022] Open
Abstract
Posttranslational modifications (PTMs) such as phosphorylation of RNA-binding proteins (RBPs) regulate several critical steps in RNA metabolism, including spliceosome assembly, alternative splicing, and mRNA export. Notably, serine-/arginine- (SR)-rich RBPs are densely phosphorylated compared with the remainder of the proteome. Previously, we showed that dephosphorylation of the splicing factor SRSF2 regulated increased interactions with similar arginine-rich RBPs U1-70K and LUC7L3. However, the large-scale functional and structural impact of these modifications on RBPs remains unclear. In this work, we dephosphorylated nuclear extracts using phosphatase in vitro and analyzed equal amounts of detergent-soluble and -insoluble fractions by mass-spectrometry-based proteomics. Correlation network analysis resolved 27 distinct modules of differentially soluble nucleoplasm proteins. We found classes of arginine-rich RBPs that decrease in solubility following dephosphorylation and enrich the insoluble pelleted fraction, including the SR protein family and the SR-like LUC7L RBP family. Importantly, increased insolubility was not observed across broad classes of RBPs. We determined that phosphorylation regulated SRSF2 structure, as dephosphorylated SRSF2 formed high-molecular-weight oligomeric species in vitro. Reciprocally, phosphorylation of SRSF2 by serine/arginine protein kinase 2 (SRPK2) in vitro decreased high-molecular-weight SRSF2 species formation. Furthermore, upon pharmacological inhibition of SRPKs in mammalian cells, we observed SRSF2 cytoplasmic mislocalization and increased formation of cytoplasmic granules as well as cytoplasmic tubular structures that associated with microtubules by immunocytochemical staining. Collectively, these findings demonstrate that phosphorylation may be a critical modification that prevents arginine-rich RBP insolubility and oligomerization.
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Affiliation(s)
- Sean R Kundinger
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Eric B Dammer
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Luming Yin
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Cheyenne Hurst
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Sarah Shapley
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Lingyan Ping
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | | | - Homa Ghalei
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA; Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA.
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15
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Zhang Z, Rigo N, Dybkov O, Fourmann JB, Will CL, Kumar V, Urlaub H, Stark H, Lührmann R. Structural insights into how Prp5 proofreads the pre-mRNA branch site. Nature 2021; 596:296-300. [PMID: 34349264 PMCID: PMC8357632 DOI: 10.1038/s41586-021-03789-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/30/2021] [Indexed: 02/07/2023]
Abstract
During the splicing of introns from precursor messenger RNAs (pre-mRNAs), the U2 small nuclear ribonucleoprotein (snRNP) must undergo stable integration into the spliceosomal A complex-a poorly understood, multistep process that is facilitated by the DEAD-box helicase Prp5 (refs. 1-4). During this process, the U2 small nuclear RNA (snRNA) forms an RNA duplex with the pre-mRNA branch site (the U2-BS helix), which is proofread by Prp5 at this stage through an unclear mechanism5. Here, by deleting the branch-site adenosine (BS-A) or mutating the branch-site sequence of an actin pre-mRNA, we stall the assembly of spliceosomes in extracts from the yeast Saccharomyces cerevisiae directly before the A complex is formed. We then determine the three-dimensional structure of this newly identified assembly intermediate by cryo-electron microscopy. Our structure indicates that the U2-BS helix has formed in this pre-A complex, but is not yet clamped by the HEAT domain of the Hsh155 protein (Hsh155HEAT), which exhibits an open conformation. The structure further reveals a large-scale remodelling/repositioning of the U1 and U2 snRNPs during the formation of the A complex that is required to allow subsequent binding of the U4/U6.U5 tri-snRNP, but that this repositioning is blocked in the pre-A complex by the presence of Prp5. Our data suggest that binding of Hsh155HEAT to the bulged BS-A of the U2-BS helix triggers closure of Hsh155HEAT, which in turn destabilizes Prp5 binding. Thus, Prp5 proofreads the branch site indirectly, hindering spliceosome assembly if branch-site mutations prevent the remodelling of Hsh155HEAT. Our data provide structural insights into how a spliceosomal helicase enhances the fidelity of pre-mRNA splicing.
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Affiliation(s)
- Zhenwei Zhang
- Department of Structural Dynamics, MPI for Biophysical Chemistry, Göttingen, Germany
| | - Norbert Rigo
- Cellular Biochemistry, MPI for Biophysical Chemistry, Göttingen, Germany
| | - Olexandr Dybkov
- Cellular Biochemistry, MPI for Biophysical Chemistry, Göttingen, Germany
| | | | - Cindy L Will
- Cellular Biochemistry, MPI for Biophysical Chemistry, Göttingen, Germany
| | - Vinay Kumar
- Cellular Biochemistry, MPI for Biophysical Chemistry, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, MPI for Biophysical Chemistry, Göttingen, Germany
- Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Holger Stark
- Department of Structural Dynamics, MPI for Biophysical Chemistry, Göttingen, Germany.
| | - Reinhard Lührmann
- Cellular Biochemistry, MPI for Biophysical Chemistry, Göttingen, Germany.
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16
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Saha K, Fernandez MM, Biswas T, Joseph S, Ghosh G. Discovery of a pre-mRNA structural scaffold as a contributor to the mammalian splicing code. Nucleic Acids Res 2021; 49:7103-7121. [PMID: 34161584 PMCID: PMC8266590 DOI: 10.1093/nar/gkab533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 06/03/2021] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
The specific recognition of splice signals at or near exon-intron junctions is not explained by their weak conservation and instead is postulated to require a multitude of features embedded in the pre-mRNA strand. We explored the possibility of 3D structural scaffold of AdML-a model pre-mRNA substrate-guiding early spliceosomal components to the splice signal sequences. We find that mutations in the non-cognate splice signal sequences impede recruitment of early spliceosomal components due to disruption of the global structure of the pre-mRNA. We further find that the pre-mRNA segments potentially interacting with the early spliceosomal component U1 snRNP are distributed across the intron, that there is a spatial proximity of 5' and 3' splice sites within the pre-mRNA scaffold, and that an interplay exists between the structural scaffold and splicing regulatory elements in recruiting early spliceosomal components. These results suggest that early spliceosomal components can recognize a 3D structural scaffold beyond the short splice signal sequences, and that in our model pre-mRNA, this scaffold is formed across the intron involving the major splice signals. This provides a conceptual basis to analyze the contribution of recognizable 3D structural scaffolds to the splicing code across the mammalian transcriptome.
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Affiliation(s)
- Kaushik Saha
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Mike Minh Fernandez
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Tapan Biswas
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Simpson Joseph
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
| | - Gourisankar Ghosh
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0375, USA
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17
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Hoskins AA, Rhoads TW. When cells are down on their LUC7L2, alternative splicing rewires metabolism for OXPHOS. Mol Cell 2021; 81:1859-1860. [PMID: 33961773 DOI: 10.1016/j.molcel.2021.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Daniels et al. (2021) and Jourdain et al. (2021) identify LUC7L2 as a component of the U1 snRNP capable of reprogramming cellular metabolism through changes in alternative pre-mRNA splicing.
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Affiliation(s)
- Aaron A Hoskins
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Timothy W Rhoads
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
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18
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Jourdain AA, Begg BE, Mick E, Shah H, Calvo SE, Skinner OS, Sharma R, Blue SM, Yeo GW, Burge CB, Mootha VK. Loss of LUC7L2 and U1 snRNP subunits shifts energy metabolism from glycolysis to OXPHOS. Mol Cell 2021; 81:1905-1919.e12. [PMID: 33852893 DOI: 10.1016/j.molcel.2021.02.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 12/18/2020] [Accepted: 02/22/2021] [Indexed: 12/17/2022]
Abstract
Oxidative phosphorylation (OXPHOS) and glycolysis are the two major pathways for ATP production. The reliance on each varies across tissues and cell states, and can influence susceptibility to disease. At present, the full set of molecular mechanisms governing the relative expression and balance of these two pathways is unknown. Here, we focus on genes whose loss leads to an increase in OXPHOS activity. Unexpectedly, this class of genes is enriched for components of the pre-mRNA splicing machinery, in particular for subunits of the U1 snRNP. Among them, we show that LUC7L2 represses OXPHOS and promotes glycolysis by multiple mechanisms, including (1) splicing of the glycolytic enzyme PFKM to suppress glycogen synthesis, (2) splicing of the cystine/glutamate antiporter SLC7A11 (xCT) to suppress glutamate oxidation, and (3) secondary repression of mitochondrial respiratory supercomplex formation. Our results connect LUC7L2 expression and, more generally, the U1 snRNP to cellular energy metabolism.
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Affiliation(s)
- Alexis A Jourdain
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | | | - Eran Mick
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Hardik Shah
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Sarah E Calvo
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Owen S Skinner
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Rohit Sharma
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Steven M Blue
- Department of Cellular and Molecular Medicine, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Vamsi K Mootha
- Department of Molecular Biology and Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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19
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Jutzi D, Campagne S, Schmidt R, Reber S, Mechtersheimer J, Gypas F, Schweingruber C, Colombo M, von Schroetter C, Loughlin FE, Devoy A, Hedlund E, Zavolan M, Allain FHT, Ruepp MD. Aberrant interaction of FUS with the U1 snRNA provides a molecular mechanism of FUS induced amyotrophic lateral sclerosis. Nat Commun 2020; 11:6341. [PMID: 33311468 PMCID: PMC7733473 DOI: 10.1038/s41467-020-20191-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 11/13/2020] [Indexed: 12/13/2022] Open
Abstract
Mutations in the RNA-binding protein Fused in Sarcoma (FUS) cause early-onset amyotrophic lateral sclerosis (ALS). However, a detailed understanding of central RNA targets of FUS and their implications for disease remain elusive. Here, we use a unique blend of crosslinking and immunoprecipitation (CLIP) and NMR spectroscopy to identify and characterise physiological and pathological RNA targets of FUS. We find that U1 snRNA is the primary RNA target of FUS via its interaction with stem-loop 3 and provide atomic details of this RNA-mediated mode of interaction with the U1 snRNP. Furthermore, we show that ALS-associated FUS aberrantly contacts U1 snRNA at the Sm site with its zinc finger and traps snRNP biogenesis intermediates in human and murine motor neurons. Altogether, we present molecular insights into a FUS toxic gain-of-function involving direct and aberrant RNA-binding and strengthen the link between two motor neuron diseases, ALS and spinal muscular atrophy (SMA).
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Affiliation(s)
- Daniel Jutzi
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Sébastien Campagne
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland
| | - Ralf Schmidt
- Computational and Systems Biology, Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Stefan Reber
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Jonas Mechtersheimer
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Foivos Gypas
- Computational and Systems Biology, Biozentrum, University of Basel, CH-4056, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, CH-4058, Basel, Switzerland
| | | | - Martino Colombo
- Celgene Institute of Translational Research (CITRE), 41092, Seville, Spain
| | - Christine von Schroetter
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland
| | - Fionna E Loughlin
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Anny Devoy
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Eva Hedlund
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Mihaela Zavolan
- Computational and Systems Biology, Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Frédéric H-T Allain
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zürich, CH-8093, Zürich, Switzerland.
| | - Marc-David Ruepp
- United Kingdom Dementia Research Institute Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK.
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20
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Chen MX, Zhang KL, Gao B, Yang JF, Tian Y, Das D, Fan T, Dai L, Hao GF, Yang GF, Zhang J, Zhu FY, Fang YM. Phylogenetic comparison of 5' splice site determination in central spliceosomal proteins of the U1-70K gene family, in response to developmental cues and stress conditions. Plant J 2020; 103:357-378. [PMID: 32133712 DOI: 10.1111/tpj.14735] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/22/2020] [Accepted: 02/04/2020] [Indexed: 05/07/2023]
Abstract
Intron-containing genes have the ability to generate multiple transcript isoforms by splicing, thereby greatly expanding the eukaryotic transcriptome and proteome. In eukaryotic cells, precursor mRNA (pre-mRNA) splicing is performed by a mega-macromolecular complex defined as a spliceosome. Among its splicing components, U1 small nuclear ribonucleoprotein (U1 snRNP) is the smallest subcomplex involved in early spliceosome assembly and 5'-splice site recognition. Its central component, named U1-70K, has been extensively characterized in animals and yeast. Very few investigations on U1-70K genes have been conducted in plants, however. To this end, we performed a comprehensive study to systematically identify 115 U1-70K genes from 67 plant species, ranging from algae to angiosperms. Phylogenetic analysis suggested that the expansion of the plant U1-70K gene family was likely to have been driven by whole-genome duplications. Subsequent comparisons of gene structures, protein domains, promoter regions and conserved splicing patterns indicated that plant U1-70Ks are likely to preserve their conserved molecular function across plant lineages and play an important functional role in response to environmental stresses. Furthermore, genetic analysis using T-DNA insertion mutants suggested that Arabidopsis U1-70K may be involved in response to osmotic stress. Our results provide a general overview of this gene family in Viridiplantae and will act as a reference source for future mechanistic studies on this U1 snRNP-specific splicing factor.
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Affiliation(s)
- Mo-Xian Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518063, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Kai-Lu Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Bei Gao
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Jing-Fang Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Yuan Tian
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Debatosh Das
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Tao Fan
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Lei Dai
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518063, China
| | - Ge-Fei Hao
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Guang-Fu Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Jianhua Zhang
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
- Department of Biology, Hong Kong Baptist University, Shatin, Hong Kong
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Fu-Yuan Zhu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
| | - Yan-Ming Fang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China
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21
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Yin Y, Lu JY, Zhang X, Shao W, Xu Y, Li P, Hong Y, Cui L, Shan G, Tian B, Zhang QC, Shen X. U1 snRNP regulates chromatin retention of noncoding RNAs. Nature 2020; 580:147-150. [PMID: 32238924 DOI: 10.1038/s41586-020-2105-3] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/09/2020] [Indexed: 12/21/2022]
Abstract
Long noncoding RNAs (lncRNAs) and promoter- or enhancer-associated unstable transcripts locate preferentially to chromatin, where some regulate chromatin structure, transcription and RNA processing1-13. Although several RNA sequences responsible for nuclear localization have been identified-such as repeats in the lncRNA Xist and Alu-like elements in long RNAs14-16-how lncRNAs as a class are enriched at chromatin remains unknown. Here we describe a random, mutagenesis-coupled, high-throughput method that we name 'RNA elements for subcellular localization by sequencing' (mutREL-seq). Using this method, we discovered an RNA motif that recognizes the U1 small nuclear ribonucleoprotein (snRNP) and is essential for the localization of reporter RNAs to chromatin. Across the genome, chromatin-bound lncRNAs are enriched with 5' splice sites and depleted of 3' splice sites, and exhibit high levels of U1 snRNA binding compared with cytoplasm-localized messenger RNAs. Acute depletion of U1 snRNA or of the U1 snRNP protein component SNRNP70 markedly reduces the chromatin association of hundreds of lncRNAs and unstable transcripts, without altering the overall transcription rate in cells. In addition, rapid degradation of SNRNP70 reduces the localization of both nascent and polyadenylated lncRNA transcripts to chromatin, and disrupts the nuclear and genome-wide localization of the lncRNA Malat1. Moreover, U1 snRNP interacts with transcriptionally engaged RNA polymerase II. These results show that U1 snRNP acts widely to tether and mobilize lncRNAs to chromatin in a transcription-dependent manner. Our findings have uncovered a previously unknown role of U1 snRNP beyond the processing of precursor mRNA, and provide molecular insight into how lncRNAs are recruited to regulatory sites to carry out chromatin-associated functions.
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Affiliation(s)
- Yafei Yin
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China.
| | - J Yuyang Lu
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
| | - Xuechun Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
| | - Wen Shao
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
| | - Yanhui Xu
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
| | - Pan Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, China
| | - Yantao Hong
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
| | - Li Cui
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
| | - Ge Shan
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui Province, China
| | - Bin Tian
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School and Rutgers Cancer Institute of New Jersey, Newark, NJ, USA
| | - Qiangfeng Cliff Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing, China
| | - Xiaohua Shen
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, China.
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22
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Oh JM, Venters CC, Di C, Pinto AM, Wan L, Younis I, Cai Z, Arai C, So BR, Duan J, Dreyfuss G. U1 snRNP regulates cancer cell migration and invasion in vitro. Nat Commun 2020; 11:1. [PMID: 31911652 PMCID: PMC6946686 DOI: 10.1038/s41467-019-13993-7] [Citation(s) in RCA: 2934] [Impact Index Per Article: 733.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
Stimulated cells and cancer cells have widespread shortening of mRNA 3'-untranslated regions (3'UTRs) and switches to shorter mRNA isoforms due to usage of more proximal polyadenylation signals (PASs) in introns and last exons. U1 snRNP (U1), vertebrates' most abundant non-coding (spliceosomal) small nuclear RNA, silences proximal PASs and its inhibition with antisense morpholino oligonucleotides (U1 AMO) triggers widespread premature transcription termination and mRNA shortening. Here we show that low U1 AMO doses increase cancer cells' migration and invasion in vitro by up to 500%, whereas U1 over-expression has the opposite effect. In addition to 3'UTR length, numerous transcriptome changes that could contribute to this phenotype are observed, including alternative splicing, and mRNA expression levels of proto-oncogenes and tumor suppressors. These findings reveal an unexpected role for U1 homeostasis (available U1 relative to transcription) in oncogenic and activated cell states, and suggest U1 as a potential target for their modulation.
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Affiliation(s)
- Jung-Min Oh
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Christopher C Venters
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Chao Di
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Anna Maria Pinto
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Lili Wan
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Ihab Younis
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Zhiqiang Cai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Chie Arai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Byung Ran So
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Jingqi Duan
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA
| | - Gideon Dreyfuss
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104-6148, USA.
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23
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Xue S, Gong R, He F, Li Y, Wang Y, Tan T, Luo SZ. Low-complexity domain of U1-70K modulates phase separation and aggregation through distinctive basic-acidic motifs. Sci Adv 2019; 5:eaax5349. [PMID: 31723601 PMCID: PMC6834393 DOI: 10.1126/sciadv.aax5349] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 09/17/2019] [Indexed: 05/20/2023]
Abstract
Liquid-liquid phase separation (LLPS) facilitates the formation of functional membraneless organelles and recent reports have linked this phenomenon to protein aggregation in neurodegenerative diseases. Understanding the mechanism of LLPS and its regulation thus promises to shed light on the pathogenesis of these conditions. The RNA-binding protein U1-70K, which aggregates in brains of Alzheimer's disease patients, is considered a potential target for Alzheimer's therapy. Here, we report that two fragments in the low-complexity (LC) domain of U1-70K can undergo LLPS. We have demonstrated that the repetitive basic-acidic motifs in these fragments induce nucleotide-independent phase separation and initiate aggregation in vitro. We also have confirmed that LLPS and aggregation occur in vivo and that the content of ampholytic motifs in a protein domain determines the transition between droplets and aggregation, providing insights into the mechanism underlying the formation of diverse assembly states.
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24
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Shih CJ, Chen HW, Hsieh HY, Lai YH, Chiu FY, Chen YR, Tu SL. Heterogeneous Nuclear Ribonucleoprotein H1 Coordinates with Phytochrome and the U1 snRNP Complex to Regulate Alternative Splicing in Physcomitrella patens. Plant Cell 2019; 31:2510-2524. [PMID: 31409629 PMCID: PMC6790087 DOI: 10.1105/tpc.19.00314] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/15/2019] [Accepted: 08/06/2019] [Indexed: 05/03/2023]
Abstract
Plant photoreceptors tightly regulate gene expression to control photomorphogenic responses. Although gene expression is modulated by photoreceptors at various levels, the regulatory mechanism at the pre-mRNA splicing step remains unclear. Alternative splicing, a widespread mechanism in eukaryotes that generates two or more mRNAs from the same pre-mRNA, is largely controlled by splicing regulators, which recruit spliceosomal components to initiate pre-mRNA splicing. The red/far-red light photoreceptor phytochrome participates in light-mediated splicing regulation, but the detailed mechanism remains unclear. Here, using protein-protein interaction analysis, we demonstrate that in the moss Physcomitrella patens, phytochrome4 physically interacts with the splicing regulator heterogeneous nuclear ribonucleoprotein H1 (PphnRNP-H1) in the nucleus, a process dependent on red light. We show that PphnRNP-H1 is involved in red light-mediated phototropic responses in P. patens and that it binds with higher affinity to the splicing factor pre-mRNA-processing factor39-1 (PpPRP39-1) in the presence of red light-activated phytochromes. Furthermore, PpPRP39-1 associates with the core component of U1 small nuclear RNP in P. patens Genome-wide analyses demonstrated the involvement of both PphnRNP-H1 and PpPRP39-1 in light-mediated splicing regulation. Our results suggest that phytochromes target the early step of spliceosome assembly via a cascade of protein-protein interactions to control pre-mRNA splicing and photomorphogenic responses.
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Affiliation(s)
- Chueh-Ju Shih
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Chung-Hsing University and Academia Sinica, Taipei 11529, Taiwan
- Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung 402, Taiwan
| | - Hsiang-Wen Chen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Hsin-Yu Hsieh
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yung-Hua Lai
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Fang-Yi Chiu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yu-Rong Chen
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Shih-Long Tu
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Chung-Hsing University and Academia Sinica, Taipei 11529, Taiwan
- Biotechnology Center, National Chung-Hsing University, Taichung 402, Taiwan
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25
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Hashiro S, Mitsuhashi M, Yasueda H. Overexpression system for recombinant RNA in Corynebacterium glutamicum using a strong promoter derived from corynephage BFK20. J Biosci Bioeng 2019; 128:255-263. [PMID: 31076339 DOI: 10.1016/j.jbiosc.2019.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/20/2019] [Accepted: 03/07/2019] [Indexed: 01/16/2023]
Abstract
In recent years, it has been shown that recombinant RNA molecules have a great potential in mRNA therapy and as novel agricultural pesticides. We developed a fundamental system for efficient production of target RNA molecules in Corynebacterium glutamicum, composed of a strong promoter named F1 and a terminator derived from corynephage BFK20 in a high-copy number plasmid vector. As a target model RNA for overexpression, we designed and used an RNA molecule [designated U1A*-RNA, ∼160 nucleotides (nt) long] containing a stem/loop II (SL-II, hairpin-II) structure from U1 small nuclear RNA (snRNA), which binds to U1A protein, forming a U1 sn-ribonucleoprotein, which is essential in the pre-mRNA splicing process. C. glutamicum strains harboring the U1A*-RNA expression plasmid were cultured and the total RNA was analyzed. We observed prominent expression of RNA corresponding to the U1A*-RNA transcript along with lower expression of a 3'-region-truncated form of the transcript (∼110 nt) in an rnc (encoding RNase III)-deficient strain. We also found that the produced U1A*-RNA bound to the U1A RNA-binding domain protein, which was separately prepared with C. glutamicum. In a batch cultivation using a fermentor, the total accumulated amount of the target RNA reached about 300 mg/L by 24 h. Thus, our results indicated that our system can serve as an efficient platform for large-scale preparation of an RNA of interest.
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Affiliation(s)
- Shuhei Hashiro
- Institute for Innovation, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan
| | - Mayu Mitsuhashi
- Institute for Innovation, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan
| | - Hisashi Yasueda
- Institute for Innovation, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan; Research and Development Center for Precision Medicine, University of Tsukuba, 1-2 Kasuga, Tsukuba-shi, Ibaraki 305-8550, Japan.
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26
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de Francisco Amorim M, Willing EM, Szabo EX, Francisco-Mangilet AG, Droste-Borel I, Maček B, Schneeberger K, Laubinger S. The U1 snRNP Subunit LUC7 Modulates Plant Development and Stress Responses via Regulation of Alternative Splicing. Plant Cell 2018; 30:2838-2854. [PMID: 30309899 PMCID: PMC6305971 DOI: 10.1105/tpc.18.00244] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 09/11/2018] [Accepted: 10/05/2018] [Indexed: 05/21/2023]
Abstract
Introns are removed by the spliceosome, a large macromolecular complex composed of five ribonucleoprotein subcomplexes (U snRNPs). The U1 snRNP, which binds to 5' splice sites, plays an essential role in early steps of the splicing reaction. Here, we show that Arabidopsis thaliana LETHAL UNLESS CBC7 (LUC7) proteins, which are encoded by a three-member gene family in Arabidopsis, are important for plant development and stress resistance. We show that LUC7 is a U1 snRNP accessory protein by RNA immunoprecipitation experiments and LUC7 protein complex purifications. Transcriptome analyses revealed that LUC7 proteins are not only important for constitutive splicing, but also affect hundreds of alternative splicing events. Interestingly, LUC7 proteins specifically promote splicing of a subset of terminal introns. Splicing of LUC7-dependent introns is a prerequisite for nuclear export, and some splicing events are modulated by stress in a LUC7-dependent manner. Taken together, our results highlight the importance of the U1 snRNP component LUC7 in splicing regulation and suggest a previously unrecognized role of a U1 snRNP accessory factor in terminal intron splicing.
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Affiliation(s)
- Marcella de Francisco Amorim
- Centre for Plant Molecular Biology (ZMBP), University of Tuebingen, 72076 Tuebingen, Germany
- Chemical Genomics Centre of the Max Planck Society, 44227 Dortmund, Germany
- Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany
| | - Eva-Maria Willing
- Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Emese X Szabo
- Centre for Plant Molecular Biology (ZMBP), University of Tuebingen, 72076 Tuebingen, Germany
- Chemical Genomics Centre of the Max Planck Society, 44227 Dortmund, Germany
- Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany
- Carl von Ossietzky University, 26129 Oldenburg, Germany
| | - Anchilie G Francisco-Mangilet
- Centre for Plant Molecular Biology (ZMBP), University of Tuebingen, 72076 Tuebingen, Germany
- Chemical Genomics Centre of the Max Planck Society, 44227 Dortmund, Germany
- Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany
- Carl von Ossietzky University, 26129 Oldenburg, Germany
| | | | - Boris Maček
- Proteome Centre, University of Tuebingen, 72076 Tuebingen, Germany
| | | | - Sascha Laubinger
- Centre for Plant Molecular Biology (ZMBP), University of Tuebingen, 72076 Tuebingen, Germany
- Chemical Genomics Centre of the Max Planck Society, 44227 Dortmund, Germany
- Max Planck Institute for Developmental Biology, 72076 Tuebingen, Germany
- Carl von Ossietzky University, 26129 Oldenburg, Germany
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27
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Bishof I, Dammer EB, Duong DM, Kundinger SR, Gearing M, Lah JJ, Levey AI, Seyfried NT. RNA-binding proteins with basic-acidic dipeptide (BAD) domains self-assemble and aggregate in Alzheimer's disease. J Biol Chem 2018; 293:11047-11066. [PMID: 29802200 PMCID: PMC6052236 DOI: 10.1074/jbc.ra118.001747] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 05/23/2018] [Indexed: 12/12/2022] Open
Abstract
The U1 small nuclear ribonucleoprotein 70 kDa (U1-70K) and other RNA-binding proteins (RBPs) are mislocalized to cytoplasmic neurofibrillary Tau aggregates in Alzheimer's disease (AD), yet the co-aggregation mechanisms are incompletely understood. U1-70K harbors two disordered low-complexity domains (LC1 and LC2) that are necessary for aggregation in AD brain extracts. The LC1 domain contains highly repetitive basic (Arg/Lys) and acidic (Asp/Glu) residues, referred to as a basic-acidic dipeptide (BAD) domain. We report here that this domain shares many of the properties of the Gln/Asn-rich LC domains in RBPs that also aggregate in neurodegenerative disease. These properties included self-assembly into oligomers and localization to nuclear granules. Co-immunoprecipitations of recombinant U1-70K and deletions lacking the LC domain(s) followed by quantitative proteomic analyses were used to resolve functional classes of U1-70K-interacting proteins that depend on the BAD domain for their interaction. Within this interaction network, we identified a class of RBPs with BAD domains nearly identical to that found in U1-70K. Two members of this class, LUC7L3 and RBM25, required their respective BAD domains for reciprocal interactions with U1-70K and nuclear granule localization. Strikingly, a significant proportion of RBPs with BAD domains had elevated insolubility in the AD brain proteome. Furthermore, we show that the BAD domain of U1-70K can interact with Tau from AD brains but not from other tauopathies. These findings highlight a mechanistic role for BAD domains in stabilizing RBP interactions and in potentially mediating co-aggregation with the pathological AD-specific Tau isoforms.
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Affiliation(s)
- Isaac Bishof
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Eric B Dammer
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Duc M Duong
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Sean R Kundinger
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Marla Gearing
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Pathology and Laboratory Medicine and
| | - James J Lah
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Neurology, and
| | - Allan I Levey
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Neurology, and
| | - Nicholas T Seyfried
- From the Departments of Biochemistry,
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Neurology, and
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28
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Martínez-Pizarro A, Dembic M, Pérez B, Andresen BS, Desviat LR. Intronic PAH gene mutations cause a splicing defect by a novel mechanism involving U1snRNP binding downstream of the 5' splice site. PLoS Genet 2018; 14:e1007360. [PMID: 29684050 PMCID: PMC5933811 DOI: 10.1371/journal.pgen.1007360] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 05/03/2018] [Accepted: 04/11/2018] [Indexed: 11/18/2022] Open
Abstract
Phenylketonuria (PKU), one of the most common inherited diseases of amino acid metabolism, is caused by mutations in the phenylalanine hydroxylase (PAH) gene. Recently, PAH exon 11 was identified as a vulnerable exon due to a weak 3’ splice site, with different exonic mutations affecting exon 11 splicing through disruption of exonic splicing regulatory elements. In this study, we report a novel intron 11 regulatory element, which is involved in exon 11 splicing, as revealed by the investigated pathogenic effect of variants c.1199+17G>A and c.1199+20G>C, identified in PKU patients. Both mutations cause exon 11 skipping in a minigene system. RNA binding assays indicate that binding of U1snRNP70 to this intronic region is disrupted, concomitant with a slightly increased binding of inhibitors hnRNPA1/2. We have investigated the effect of deletions and point mutations, as well as overexpression of adapted U1snRNA to show that this splicing regulatory motif is important for regulation of correct splicing at the natural 5’ splice site. The results indicate that U1snRNP binding downstream of the natural 5’ splice site determines efficient exon 11 splicing, thus providing a basis for development of therapeutic strategies to correct PAH exon 11 splicing mutations. In this work, we expand the functional effects of non-canonical intronic U1 snRNP binding by showing that it may enhance exon definition and that, consequently, intronic mutations may cause exon skipping by a novel mechanism, where they disrupt stimulatory U1 snRNP binding close to the 5’ splice site. Notably, our results provide further understanding of the reported therapeutic effect of exon specific U1 snRNA for splicing mutations in disease. Splicing defects constitute a major cause of human disease. Mutations affecting conserved splicing sequences at exon-intron junctions are easily recognized as possibly pathogenic, whereas variants in exonic or intronic regions are difficult to classify without functional evidence provided by transcript analysis or in vitro analysis using minigenes. In this work, we sought out to study the pathogenicity of two novel intronic PAH variants identified in phenylketonuria patients. Both mutations resulted in exon skipping in minigenes. We demonstrate that U1snRNP70 binds to the intronic region and that this binding is abolished in the mutant sequences. Correction of the splicing defect was achieved using modified U1 snRNA perfectly complementary to each of the mutant sequences. The results extend the repertoire of natural U1 snRNP cellular functions by including its role as splicing enhancer via binding downstream of the natural 5’ splice site. In addition, our results correlate with the described therapeutic effect of modified U1snRNP for splicing mutations in different genes, thus having a significant impact in the development of specific therapies for splicing defects.
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Affiliation(s)
- Ainhoa Martínez-Pizarro
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, CEDEM, CIBERER, IdiPaz, Universidad Autónoma, Madrid, Spain
| | - Maja Dembic
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, Odense, Denmark
| | - Belén Pérez
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, CEDEM, CIBERER, IdiPaz, Universidad Autónoma, Madrid, Spain
| | - Brage S. Andresen
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, Odense, Denmark
- * E-mail: (BSA); (LRD)
| | - Lourdes R. Desviat
- Centro de Biología Molecular Severo Ochoa UAM-CSIC, CEDEM, CIBERER, IdiPaz, Universidad Autónoma, Madrid, Spain
- * E-mail: (BSA); (LRD)
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29
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Abstract
Gemin5 acts as a U1 small nuclear RNA (snRNA)-binding protein in U1 small nuclear ribonucleic protein (snRNP) biogenesis. Here, we report a role for Gemin5 in unassembled U1 snRNP disposal under survival of motor neuron (SMN) protein-deficient conditions. We demonstrate that non-Sm protein-associated U1 snRNA and U1A are enriched in cytoplasmic granules and colocalize to P bodies in SMN-deficient cells. Immunoprecipitation assays show increased associations of the U1 snRNP component U1A with P body components and Gemin5 in SMN-deficient cells. More importantly, Gemin5 knockdown eliminates the unassembled U1 snRNP granules and rescues U1 snRNA levels in SMN-deficient cells. Taken together, our study provides direct evidence that Gemin5 is involved in unassembled-U1 snRNA disposal under conditions of SMN deficiency.
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Affiliation(s)
- Dongxu Jiang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
- Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Xuan Zou
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
| | - Cheng Zhang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
| | - Jincao Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
| | - Zhiqiang Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
| | - Yunfu Wang
- Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
| | - Liangrong Wang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
| | - Shi Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, and Brain Center, Zhongnan Hospital, Wuhan University, China
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Hálová M, Gahura O, Převorovský M, Cit Z, Novotný M, Valentová A, Abrhámová K, Půta F, Folk P. Nineteen complex-related factor Prp45 is required for the early stages of cotranscriptional spliceosome assembly. RNA 2017; 23:1512-1524. [PMID: 28701519 PMCID: PMC5602110 DOI: 10.1261/rna.061986.117] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/21/2017] [Indexed: 05/22/2023]
Abstract
Splicing in S. cerevisiae has been shown to proceed cotranscriptionally, but the nature of the coupling remains a subject of debate. Here, we examine the effect of nineteen complex-related splicing factor Prp45 (a homolog of SNW1/SKIP) on cotranscriptional splicing. RNA-sequencing and RT-qPCR showed elevated pre-mRNA levels but only limited reduction of spliced mRNAs in cells expressing C-terminally truncated Prp45, Prp45(1-169). Assays with a series of reporters containing the AMA1 intron with regulatable splicing confirmed decreased splicing efficiency and showed the leakage of unspliced RNAs in prp45(1-169) cells. We also measured pre-mRNA accumulation of the meiotic MER2 gene, which depends on the expression of Mer1 factor for splicing. prp45(1-169) cells accumulated approximately threefold higher levels of MER2 pre-mRNA than WT cells only when splicing was induced. To monitor cotranscriptional splicing, we determined the presence of early spliceosome assembly factors and snRNP complexes along the ECM33 and ACT1 genes. We found that prp45(1-169) hampered the cotranscriptional recruitment of U2 and, to a larger extent, U5 and NTC, while the U1 profile was unaffected. The recruitment of Prp45(1-169) was impaired similarly to U5 snRNP and NTC. Our results imply that Prp45 is required for timely formation of complex A, prior to stable physical association of U5/NTC with the emerging pre-mRNA substrate. We suggest that Prp45 facilitates conformational rearrangements and/or contacts that couple U1 snRNP-recognition to downstream assembly events.
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Affiliation(s)
- Martina Hálová
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Ondřej Gahura
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Zdeněk Cit
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Marian Novotný
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Anna Valentová
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Kateřina Abrhámová
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - František Půta
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
| | - Petr Folk
- Department of Cell Biology, Faculty of Science, Charles University, 128 00 Prague, Czech Republic
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Ohe K, Yoshida M, Nakano-Kobayashi A, Hosokawa M, Sako Y, Sakuma M, Okuno Y, Usui T, Ninomiya K, Nojima T, Kataoka N, Hagiwara M. RBM24 promotes U1 snRNP recognition of the mutated 5' splice site in the IKBKAP gene of familial dysautonomia. RNA 2017; 23:1393-1403. [PMID: 28592461 PMCID: PMC5558909 DOI: 10.1261/rna.059428.116] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
The 5' splice site mutation (IVS20+6T>C) of the inhibitor of κ light polypeptide gene enhancer in B cells, kinase complex-associated protein (IKBKAP) gene in familial dysautonomia (FD) is at the sixth intronic nucleotide of the 5' splice site. It is known to weaken U1 snRNP recognition and result in an aberrantly spliced mRNA product in neuronal tissue, but normally spliced mRNA in other tissues. Aberrantly spliced IKBKAP mRNA abrogates IKK complex-associated protein (IKAP)/elongator protein 1 (ELP1) expression and results in a defect of neuronal cell development in FD. To elucidate the tissue-dependent regulatory mechanism, we screened an expression library of major RNA-binding proteins (RBPs) with our mammalian dual-color splicing reporter system and identified RBM24 as a regulator. RBM24 functioned as a cryptic intronic splicing enhancer binding to an element (IVS20+13-29) downstream from the intronic 5' splice site mutation in the IKBKAP gene and promoted U1 snRNP recognition only to the mutated 5' splice site (and not the wild-type 5' splice site). Our results show that tissue-specific expression of RBM24 can explain the neuron-specific aberrant splicing of IKBKAP exon 20 in familial dysautonomia, and that ectopic expression of RBM24 in neuronal tissue could be a novel therapeutic target of the disease.
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Affiliation(s)
- Kenji Ohe
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
- Training Program of Leaders for Integrated Medical System for Fruitful Healthy-Longevity Society (LIMS), Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Mayumi Yoshida
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Akiko Nakano-Kobayashi
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Motoyasu Hosokawa
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yukiya Sako
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Maki Sakuma
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yukiko Okuno
- Medical Research Support Center, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Tomomi Usui
- Laboratory of Gene Expression, School of Biomedical Science, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Kensuke Ninomiya
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takayuki Nojima
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Naoyuki Kataoka
- Laboratory for Malignancy Control Research, Medical Innovation Center, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8507, Japan
- Laboratory of Cell Regulation, Departments of Applied Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Masatoshi Hagiwara
- Department of Anatomy and Developmental Biology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan
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Agarwal R, Schwer B, Shuman S. Structure-function analysis and genetic interactions of the Luc7 subunit of the Saccharomyces cerevisiae U1 snRNP. RNA 2016; 22:1302-10. [PMID: 27354704 PMCID: PMC4986886 DOI: 10.1261/rna.056911.116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 05/19/2016] [Indexed: 05/08/2023]
Abstract
Luc7 is an essential 261-amino acid protein subunit of the Saccharomyces cerevisiae U1 snRNP. To establish structure-function relations for yeast Luc7, we conducted an in vivo mutational analysis entailing N- and C-terminal truncations and alanine scanning of phylogenetically conserved amino acids, including two putative zinc finger motifs, ZnF1 and ZnF2, and charged amino acids within the ZnF2 module. We identify Luc7-(31-246) as a minimal functional protein and demonstrate that whereas mutations of the CCHH ZnF2 motif are lethal, mutations of the ZnF1 CCCH motif and the charged residues of the ZnF2 modules are not. Though dispensable for vegetative growth in an otherwise wild-type background, the N-terminal 18-amino acid segment of Luc7 plays an important role in U1 snRNP function, evinced by our findings that its deletion (i) impaired the splicing of SUS1 pre-mRNA; (ii) was synthetically lethal absent other U1 snRNP constituents (Mud1, Nam8, the TMG cap, the C terminus of Snp1), absent the Mud2 subunit of the Msl5•Mud2 branchpoint binding complex, and when the m(7)G cap-binding site of Cbc2 was debilitated; and (iii) bypassed the need for the essential DEAD-box ATPase Prp28. Similar phenotypes were noted for ZnF1 mutations C45A, C53A, and C68A and ZnF2 domain mutations D214A, R215A, R216A, and D219A These findings highlight the contributions of the Luc7 N-terminal peptide, the ZnF1 motif, and the ZnF2 module in stabilizing the interactions of the U1 snRNP with the pre-mRNA 5' splice site and promoting the splicing of a yeast pre-mRNA, SUS1, that has a nonconsensus 5' splice site.
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Affiliation(s)
- Radhika Agarwal
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
| | - Beate Schwer
- Microbiology and Immunology Department, Weill Cornell Medical College, New York, New York 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
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Pieperhoff MS, Pall GS, Jiménez-Ruiz E, Das S, Melatti C, Gow M, Wong EH, Heng J, Müller S, Blackman MJ, Meissner M. Conditional U1 Gene Silencing in Toxoplasma gondii. PLoS One 2015; 10:e0130356. [PMID: 26090798 PMCID: PMC4474610 DOI: 10.1371/journal.pone.0130356] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 05/18/2015] [Indexed: 11/19/2022] Open
Abstract
The functional characterisation of essential genes in apicomplexan parasites, such as Toxoplasma gondii or Plasmodium falciparum, relies on conditional mutagenesis systems. Here we present a novel strategy based on U1 snRNP-mediated gene silencing. U1 snRNP is critical in pre-mRNA splicing by defining the exon-intron boundaries. When a U1 recognition site is placed into the 3'-terminal exon or adjacent to the termination codon, pre-mRNA is cleaved at the 3'-end and degraded, leading to an efficient knockdown of the gene of interest (GOI). Here we describe a simple method that combines endogenous tagging with DiCre-mediated positioning of U1 recognition sites adjacent to the termination codon of the GOI which leads to a conditional knockdown of the GOI upon rapamycin-induction. Specific knockdown mutants of the reporter gene GFP and several endogenous genes of T. gondii including the clathrin heavy chain gene 1 (chc1), the vacuolar protein sorting gene 26 (vps26), and the dynamin-related protein C gene (drpC) were silenced using this approach and demonstrate the potential of this technology. We also discuss advantages and disadvantages of this method in comparison to other technologies in more detail.
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Affiliation(s)
- Manuela S. Pieperhoff
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Gurman S. Pall
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Elena Jiménez-Ruiz
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Sujaan Das
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom
| | - Carmen Melatti
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Matthew Gow
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Eleanor H. Wong
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Joanne Heng
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Sylke Müller
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
| | - Michael J. Blackman
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London, United Kingdom
- * E-mail: (MM); (MJB)
| | - Markus Meissner
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, Glasgow, Lanarkshire, United Kingdom
- * E-mail: (MM); (MJB)
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Schwer B, Shuman S. Structure-function analysis and genetic interactions of the Yhc1, SmD3, SmB, and Snp1 subunits of yeast U1 snRNP and genetic interactions of SmD3 with U2 snRNP subunit Lea1. RNA 2015; 21:1173-86. [PMID: 25897024 PMCID: PMC4436669 DOI: 10.1261/rna.050583.115] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/04/2015] [Indexed: 05/08/2023]
Abstract
Yhc1 and U1-C are essential subunits of the yeast and human U1 snRNP, respectively, that stabilize the duplex formed by U1 snRNA at the pre-mRNA 5' splice site (5'SS). Mutational analysis of Yhc1, guided by the human U1 snRNP crystal structure, highlighted the importance of Val20 and Ser19 at the RNA interface. Though benign on its own, V20A was lethal in the absence of branchpoint-binding complex subunit Mud2 and caused a severe growth defect in the absence of U1 subunit Nam8. S19A caused a severe defect with mud2▵. Essential DEAD-box ATPase Prp28 was bypassed by mutations of Yhc1 Val20 and Ser19, consistent with destabilization of U1•5'SS interaction. We extended the genetic analysis to SmD3, which interacts with U1-C/Yhc1 in U1 snRNP, and to SmB, its neighbor in the Sm ring. Whereas mutations of the interface of SmD3, SmB, and U1-C/Yhc1 with U1-70K/Snp1, or deletion of the interacting Snp1 N-terminal peptide, had no growth effect, they elicited synthetic defects in the absence of U1 subunit Mud1. Mutagenesis of the RNA-binding triad of SmD3 (Ser-Asn-Arg) and SmB (His-Asn-Arg) provided insights to built-in redundancies of the Sm ring, whereby no individual side-chain was essential, but simultaneous mutations of Asn or Arg residues in SmD3 and SmB were lethal. Asn-to-Ala mutations SmB and SmD3 caused synthetic defects in the absence of Mud1 or Mud2. All three RNA site mutations of SmD3 were lethal in cells lacking the U2 snRNP subunit Lea1. Benign C-terminal truncations of SmD3 were dead in the absence of Mud2 or Lea1 and barely viable in the absence of Nam8 or Mud1. In contrast, SMD3-E35A uniquely suppressed the temperature-sensitivity of lea1▵.
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MESH Headings
- Autoantigens/chemistry
- Autoantigens/genetics
- Autoantigens/metabolism
- Binding Sites
- DNA Mutational Analysis
- Humans
- Models, Molecular
- Protein Structure, Tertiary
- Ribonucleoprotein, U1 Small Nuclear/chemistry
- Ribonucleoprotein, U1 Small Nuclear/genetics
- Ribonucleoprotein, U1 Small Nuclear/metabolism
- Ribonucleoprotein, U2 Small Nuclear/chemistry
- Ribonucleoprotein, U2 Small Nuclear/genetics
- Ribonucleoprotein, U2 Small Nuclear/metabolism
- Ribonucleoproteins, Small Nuclear/chemistry
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/growth & development
- Saccharomyces cerevisiae Proteins/chemistry
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
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Affiliation(s)
- Beate Schwer
- Microbiology and Immunology Department, Weill Cornell Medical College, New York, New York 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, New York 10065, USA
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Nagai K. In the beginning was the U1A protein: a personal reflection. RNA 2015; 21:699-700. [PMID: 25780197 PMCID: PMC4371339 DOI: 10.1261/rna.050344.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Kiyoshi Nagai
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
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Song Y, Chen SL, Shen N, Xue F, Ye P, Bao CD, Gu YY, Yu CZ, Lu LJ. Expression, localization, and clinical application of the RNA binding domain of U1-70kD in HEp-2 cells. Ann Clin Lab Sci 2015; 45:134-139. [PMID: 25887865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To develop an improved substrate for indirect immunofluorescent test (IIF) to detect anti-U1-70kD autoantibodies. METHODS The RNA binding domain of U1-70kD (U1BD) complementary DNA was obtained from human larynx carcinoma cell line HEp-2 by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into the mammalian expression vector pEGFP-C1. The recombinant plasmid pEGFP-U1BD was transfected into HEp-2 cells. Immunoblotting (IBT), confocal fluorescence microscopy, and IIF were used to confirm the expression, localization, and antigenicity of fusion proteins of green fluorescent protein (GFP) in transfected HEp-2 cells, which were then analyzed by IIF using human reference sera and compared with untransfected HEp-2 cells simultaneously. RESULTS (1) The HEp-U1BD cells thus obtained retained their ability to express U1BD-GFP, which showed the antigenicity of U1BD with a characteristic phenotype in IIF. (2) Fifteen IBT-positive anti-U1-70kD sera presented with characteristic cytoplasmic staining on HEp-U1BD by IIF, but five sera without the 70kD reactive band in IBT were not found in the presence of HEp-U1BD pattern. Ten sera of healthy donors couldn't react with HEp-2 and HEp-U1BD at 1:80 attenuant degrees. (3) No differences in expression, localization, or morphology were observed when HEp-U1BD or HEp-2 interacted with the reference sera that could react with Ro/SSA, La/SSB, centromere, histone, and Scl-70 antigens in routine IIF test. CONCLUSIONS HEp-U1BD cells kept the immunofluorescent properties of HEp-2 cells in an immunofluorescence anti-nuclear antibody (IFANA) test and could be potentially used as a substrate for routine IFANA detection.
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Affiliation(s)
- Yang Song
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shun-le Chen
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Nan Shen
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Feng Xue
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Ye
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chun-de Bao
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yue-ying Gu
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chong-zhao Yu
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Liang-jing Lu
- Department of Rheumatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Maatz H, Jens M, Liss M, Schafer S, Heinig M, Kirchner M, Adami E, Rintisch C, Dauksaite V, Radke MH, Selbach M, Barton PJR, Cook SA, Rajewsky N, Gotthardt M, Landthaler M, Hubner N. RNA-binding protein RBM20 represses splicing to orchestrate cardiac pre-mRNA processing. J Clin Invest 2014; 124:3419-30. [PMID: 24960161 DOI: 10.1172/jci74523] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 05/13/2014] [Indexed: 12/26/2022] Open
Abstract
Mutations in the gene encoding the RNA-binding protein RBM20 have been implicated in dilated cardiomyopathy (DCM), a major cause of chronic heart failure, presumably through altering cardiac RNA splicing. Here, we combined transcriptome-wide crosslinking immunoprecipitation (CLIP-seq), RNA-seq, and quantitative proteomics in cell culture and rat and human hearts to examine how RBM20 regulates alternative splicing in the heart. Our analyses revealed the presence of a distinct RBM20 RNA-recognition element that is predominantly found within intronic binding sites and linked to repression of exon splicing with RBM20 binding near 3' and 5' splice sites. Proteomic analysis determined that RBM20 interacts with both U1 and U2 small nuclear ribonucleic particles (snRNPs) and suggested that RBM20-dependent splicing repression occurs through spliceosome stalling at complex A. Direct RBM20 targets included several genes previously shown to be involved in DCM as well as genes not typically associated with this disease. In failing human hearts, reduced expression of RBM20 affected alternative splicing of several direct targets, indicating that differences in RBM20 expression may affect cardiac function. Together, these findings identify RBM20-regulated targets and provide insight into the pathogenesis of human heart failure.
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Kamoun M, Filali M, Murray MV, Awasthi S, Wadzinski BE. Protein phosphatase 2A family members (PP2A and PP6) associate with U1 snRNP and the spliceosome during pre-mRNA splicing. Biochem Biophys Res Commun 2013; 440:306-11. [PMID: 24064353 PMCID: PMC3891829 DOI: 10.1016/j.bbrc.2013.09.068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 09/13/2013] [Indexed: 11/23/2022]
Abstract
Protein phosphorylation and dephosphorylation are both important for multiple steps in the splicing pathway. Members of the PP1 and PP2A subfamilies of phospho-serine/threonine phosphatases play essential but redundant roles in the second step of the splicing reaction. PP6, a member of the PP2A subfamily, is the mammalian homolog of yeast Sit4p and ppe1, which are involved in cell cycle regulation; however, the involvement of PP6 in the splicing pathway remains unclear. Here we show that PP2A family members physically associate with the spliceosome throughout the splicing reaction. PP2A holoenzyme and PP6 were found stably associated with U1 snRNP. Together our findings indicate that these phosphatases regulate splicing catalysis involving U1 snRNP and suggest an important evolutionary conserved role of PP2A family phosphatases in pre-mRNA splicing.
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Affiliation(s)
- Malek Kamoun
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
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Pabis M, Neufeld N, Steiner MC, Bojic T, Shav-Tal Y, Neugebauer KM. The nuclear cap-binding complex interacts with the U4/U6·U5 tri-snRNP and promotes spliceosome assembly in mammalian cells. RNA 2013; 19:1054-63. [PMID: 23793891 PMCID: PMC3708526 DOI: 10.1261/rna.037069.112] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Accepted: 04/24/2013] [Indexed: 05/23/2023]
Abstract
The nuclear cap-binding complex (CBC) binds to the 7-methyl guanosine cap present on every RNA polymerase II transcript. CBC has been implicated in many aspects of RNA biogenesis; in addition to roles in miRNA biogenesis, nonsense-mediated decay, 3'-end formation, and snRNA export from the nucleus, CBC promotes pre-mRNA splicing. An unresolved question is how CBC participates in splicing. To investigate CBC's role in splicing, we used mass spectrometry to identify proteins that copurify with mammalian CBC. Numerous components of spliceosomal snRNPs were specifically detected. Among these, three U4/U6·U5 snRNP proteins (hBrr2, hPrp4, and hPrp31) copurified with CBC in an RNA-independent fashion, suggesting that a significant fraction of CBC forms a complex with the U4/U6·U5 snRNP and that the activity of CBC might be associated with snRNP recruitment to pre-mRNA. To test this possibility, CBC was depleted from HeLa cells by RNAi. Chromatin immunoprecipitation and live-cell imaging assays revealed decreased cotranscriptional accumulation of U4/U6·U5 snRNPs on active transcription units, consistent with a requirement for CBC in cotranscriptional spliceosome assembly. Surprisingly, recruitment of U1 and U2 snRNPs was also affected, indicating that RNA-mediated interactions between CBC and snRNPs contribute to splicing. On the other hand, CBC depletion did not impair snRNP biogenesis, ruling out the possibility that decreased snRNP recruitment was due to changes in nuclear snRNP concentration. Taken together, the data support a model whereby CBC promotes pre-mRNA splicing through a network of interactions with and among spliceosomal snRNPs during cotranscriptional spliceosome assembly.
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Affiliation(s)
- Marta Pabis
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Noa Neufeld
- The Mina & Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Michaela C. Steiner
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Teodora Bojic
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Yaron Shav-Tal
- The Mina & Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Karla M. Neugebauer
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
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40
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Almada AE, Wu X, Kriz AJ, Burge CB, Sharp PA. Promoter directionality is controlled by U1 snRNP and polyadenylation signals. Nature 2013; 499:360-3. [PMID: 23792564 PMCID: PMC3720719 DOI: 10.1038/nature12349] [Citation(s) in RCA: 303] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 06/04/2013] [Indexed: 11/22/2022]
Abstract
Transcription of the mammalian genome is pervasive, but productive transcription outside of protein-coding genes is limited by unknown mechanisms. In particular, although RNA polymerase II (RNAPII) initiates divergently from most active gene promoters, productive elongation occurs primarily in the sense-coding direction. Here we show in mouse embryonic stem cells that asymmetric sequence determinants flanking gene transcription start sites control promoter directionality by regulating promoter-proximal cleavage and polyadenylation. We find that upstream antisense RNAs are cleaved and polyadenylated at poly(A) sites (PASs) shortly after initiation. De novo motif analysis shows PAS signals and U1 small nuclear ribonucleoprotein (snRNP) recognition sites to be the most depleted and enriched sequences, respectively, in the sense direction relative to the upstream antisense direction. These U1 snRNP sites and PAS sites are progressively gained and lost, respectively, at the 5' end of coding genes during vertebrate evolution. Functional disruption of U1 snRNP activity results in a dramatic increase in promoter-proximal cleavage events in the sense direction with slight increases in the antisense direction. These data suggest that a U1-PAS axis characterized by low U1 snRNP recognition and a high density of PASs in the upstream antisense region reinforces promoter directionality by promoting early termination in upstream antisense regions, whereas proximal sense PAS signals are suppressed by U1 snRNP. We propose that the U1-PAS axis limits pervasive transcription throughout the genome.
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Affiliation(s)
- Albert E. Almada
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 0239 USA
| | - Xuebing Wu
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
- Computational and Systems Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Andrea J. Kriz
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 0239 USA
| | - Christopher B. Burge
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 0239 USA
- Computational and Systems Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Phillip A. Sharp
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 0239 USA
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41
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Abstract
The U1A/U2B″/SNF family of proteins found in the U1 and U2 spliceosomal small nuclear ribonucleoproteins is highly conserved. In spite of the high degree of sequence and structural conservation, modern members of this protein family have unique RNA binding properties. These differences have necessarily resulted from evolutionary processes, and therefore, we reconstructed the protein phylogeny in order to understand how and when divergence occurred and how protein function has been modulated. Contrary to the conventional understanding of an ancient human U1A/U2B″ gene duplication, we show that the last common ancestor of bilaterians contained a single ancestral protein (URB). The gene for URB was synthesized, the protein was overexpressed and purified, and we assessed RNA binding to modern snRNA sequences. We find that URB binds human and Drosophila U1 snRNA SLII and U2 snRNA SLIV with higher affinity than do modern homologs, suggesting that both Drosophila SNF and human U1A/U2B″ have evolved into weaker binders of one RNA or both RNAs.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Drosophila
- Drosophila Proteins/chemistry
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Evolution, Molecular
- Gene Duplication
- Humans
- Inverted Repeat Sequences
- Models, Molecular
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phylogeny
- Protein Binding
- Protein Conformation
- RNA, Small Nuclear/chemistry
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- Ribonucleoprotein, U1 Small Nuclear/chemistry
- Ribonucleoprotein, U1 Small Nuclear/genetics
- Ribonucleoprotein, U1 Small Nuclear/metabolism
- Ribonucleoproteins, Small Nuclear/chemistry
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/metabolism
- Sequence Alignment
- Spliceosomes/metabolism
- snRNP Core Proteins/chemistry
- snRNP Core Proteins/genetics
- snRNP Core Proteins/metabolism
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Affiliation(s)
- Sandra G Williams
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63108, USA
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42
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Shen M, Bellaousov S, Hiller M, de La Grange P, Creamer TP, Malina O, Sperling R, Mathews DH, Stoilov P, Stamm S. Pyrvinium pamoate changes alternative splicing of the serotonin receptor 2C by influencing its RNA structure. Nucleic Acids Res 2013; 41:3819-32. [PMID: 23393189 PMCID: PMC3616728 DOI: 10.1093/nar/gkt063] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/08/2013] [Accepted: 01/15/2013] [Indexed: 01/17/2023] Open
Abstract
The serotonin receptor 2C plays a central role in mood and appetite control. It undergoes pre-mRNA editing as well as alternative splicing. The RNA editing suggests that the pre-mRNA forms a stable secondary structure in vivo. To identify substances that promote alternative exons inclusion, we set up a high-throughput screen and identified pyrvinium pamoate as a drug-promoting exon inclusion without editing. Circular dichroism spectroscopy indicates that pyrvinium pamoate binds directly to the pre-mRNA and changes its structure. SHAPE (selective 2'-hydroxyl acylation analysed by primer extension) assays show that part of the regulated 5'-splice site forms intramolecular base pairs that are removed by this structural change, which likely allows splice site recognition and exon inclusion. Genome-wide analyses show that pyrvinium pamoate regulates >300 alternative exons that form secondary structures enriched in A-U base pairs. Our data demonstrate that alternative splicing of structured pre-mRNAs can be regulated by small molecules that directly bind to the RNA, which is reminiscent to an RNA riboswitch.
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MESH Headings
- Alternative Splicing/drug effects
- Base Sequence
- Exons
- HEK293 Cells
- High-Throughput Screening Assays
- Humans
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phylogeny
- Pyrvinium Compounds/metabolism
- Pyrvinium Compounds/pharmacology
- RNA Editing
- RNA Precursors/metabolism
- RNA, Double-Stranded/chemistry
- RNA, Double-Stranded/drug effects
- RNA, Messenger/chemistry
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Receptor, Serotonin, 5-HT2C/genetics
- Receptor, Serotonin, 5-HT2C/metabolism
- Ribonucleoprotein, U1 Small Nuclear/metabolism
- Spliceosomes/metabolism
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Affiliation(s)
- Manli Shen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Stanislav Bellaousov
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Michael Hiller
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Pierre de La Grange
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Trevor P. Creamer
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Orit Malina
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Ruth Sperling
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - David H. Mathews
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Peter Stoilov
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
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43
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Abstract
Alternative splicing (AS) is a major contributor to proteome diversity, but it also regulates gene expression by introducing premature termination codons (PTCs) that destabilize transcripts, typically via the nonsense-mediated decay (NMD) pathway. Such AS events often take place within long, conserved sequence elements, particularly in genes encoding various RNA binding proteins. AS-NMD is often activated by the protein encoded by the same gene, leading to a self-regulating feedback loop that maintains constant protein levels. However, cross-regulation between different RNA binding proteins is also common, giving rise to finely tuned regulatory networks. Recently, we described a feedback mechanism regulating two protein components of the U12-dependent spliceosome (U11-48K and U11/U12-65K) through a highly conserved sequence element. These elements contain a U11 snRNP-binding splicing enhancer (USSE), which, through the U11 snRNP, activates an upstream U2-type 3'ss, resulting in the degradation of the U11-48K mRNA by AS-NMD. Through phylogenetic analysis, we now identify a G-rich sequence element that is conserved in fishes as well as mammals. We show that this element binds hnRNPF/H proteins in vitro. Knockdown of hnRNPH1/H2 or mutations in the G-run both lead to enhanced activation of the 3'ss in vivo, suggesting that hnRNPH1/H2 proteins counteract the 3'ss activation. Furthermore, we provide evidence that U1 binding immediately downstream from the G-run similarly counteracts the U11-mediated activation of the alternative 3'ss. Thus, our results elucidate the mechanism in which snRNPs from both spliceosomes together with hnRNPH1/H2 proteins regulate the recognition and activation of the highly conserved alternative splice sites within the U11-48K pre-mRNA.
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44
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Day IS, Golovkin M, Palusa SG, Link A, Ali GS, Thomas J, Richardson DN, Reddy ASN. Interactions of SR45, an SR-like protein, with spliceosomal proteins and an intronic sequence: insights into regulated splicing. Plant J 2012; 71:936-47. [PMID: 22563826 DOI: 10.1111/j.1365-313x.2012.05042.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
SR45 is a serine/arginine-rich (SR)-like protein with two arginine/serine-rich (RS) domains. We have previously shown that SR45 regulates alternative splicing (AS) by differential selection of 5' and 3' splice sites. However, it is unknown how SR45 regulates AS. To gain mechanistic insights into the roles of SR45 in splicing, we screened a yeast two-hybrid library with SR45. This screening resulted in the isolation of two spliceosomal proteins, U1-70K and U2AF(35) b that are known to function in 5' and 3' splice site selection, respectively. This screen not only confirmed our prior observation that U1-70K and SR45 interact, but also helped to identify an additional interacting partner (U2AF(35) ). In vitro and in vivo analyses revealed an interaction of SR45 with both paralogs of U2AF(35) . Furthermore, we show that the RS1 and RS2 domains of SR45, and not the RNA recognition motif (RRM) domain, associate independently with both U2AF(35) proteins. Interaction studies among U2AF(35) paralogs and between U2AF(35) and U1-70K revealed that U2AF(35) can form homo- or heterodimers and that U2AF(35) proteins can associate with U1-70K. Using RNA probes from SR30 intron 10, whose splicing is altered in the sr45 mutant, we show that SR45 and U2AF(35) b bind to different parts of the intron, with a binding site for SR45 in the 5' region and two binding regions, each ending with a known 3' splice site, for U2AF(35) b. These results suggest that SR45 recruits U1snRNP and U2AF to 5' and 3' splice sites, respectively, by interacting with pre-mRNA, U1-70K and U2AF(35) and modulates AS.
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Affiliation(s)
- Irene S Day
- Department of Biology, Program in Molecular Plant Biology, Program in Cell and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
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45
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Bardaro MF, Varani G. Independent alignment of RNA for dynamic studies using residual dipolar couplings. J Biomol NMR 2012; 54:69-80. [PMID: 22806132 DOI: 10.1007/s10858-012-9655-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 06/26/2012] [Indexed: 06/01/2023]
Abstract
Molecular motion and dynamics play an essential role in the biological function of many RNAs. An important source of information on biomolecular motion can be found in residual dipolar couplings which contain dynamics information over the entire ms-ps timescale. However, these methods are not fully applicable to RNA because nucleic acid molecules tend to align in a highly collinear manner in different alignment media. As a consequence, information on dynamics that can be obtained with this method is limited. In order to overcome this limitation, we have generated a chimeric RNA containing both the wild type TAR RNA, the target of our investigation of dynamics, as well as the binding site for U1A protein. When U1A protein was bound to the portion of the chimeric RNA containing its binding site, we obtained independent alignment of TAR by exploiting the physical chemical characteristics of this protein. This technique can allow the extraction of new information on RNA dynamics, which is particularly important for time scales not covered by relaxation methods where important RNA motions occur.
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Affiliation(s)
- Michael F Bardaro
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195, USA
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46
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Görnemann J, Barrandon C, Hujer K, Rutz B, Rigaut G, Kotovic KM, Faux C, Neugebauer KM, Séraphin B. Cotranscriptional spliceosome assembly and splicing are independent of the Prp40p WW domain. RNA 2011; 17:2119-29. [PMID: 22020974 PMCID: PMC3222125 DOI: 10.1261/rna.02646811] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Complex cellular functions involve large networks of interactions. Pre-mRNA splicing and transcription are thought to be coupled by the C-terminal domain (CTD) of the large subunit of RNA polymerase II (Pol II). In yeast, the U1 snRNP subunit Prp40 was proposed to mediate cotranscriptional recruitment of early splicing factors through binding of its WW domains to the Pol II CTD. Here we investigate the role of Prp40 in splicing with an emphasis on the role of the WW domains, which might confer protein-protein interactions among the splicing and transcriptional machineries. Affinity purification revealed that Prp40 and Snu71 form a stable heterodimer that stably associates with the U1 snRNP only in the presence of Nam8, a known regulator of 5' splice site recognition. However, the Prp40 WW domains were dispensable for yeast viability. In their absence, no defect in splicing in vivo, U1 or U2 snRNP recruitment in vivo, or early splicing complex assembly in vitro was detected. We conclude that the WW domains of Prp40 do not mediate essential coupling between U1 snRNP and Pol II. Instead, delays in cotranscriptional U5 snRNP and Prp19 recruitment and altered spliceosome formation in vitro suggest that Prp40 WW domains assist in late steps of spliceosome assembly.
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Affiliation(s)
- Janina Görnemann
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | | | - Katja Hujer
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | | | | | - Kimberly M. Kotovic
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Céline Faux
- CGM, CNRS, 91198 Gif sur Yvette Cedex, France
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de Santé et de Recherche Médicale (INSERM) U964/Centre National de Recherche Scientifique (CNRS) UMR 7104/Université de Strasbourg, 67404 Illkirch, France
| | - Karla M. Neugebauer
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
- Corresponding authors.E-mail E-mail .
| | - Bertrand Séraphin
- CGM, CNRS, 91198 Gif sur Yvette Cedex, France
- EMBL, D-69117 Heidelberg, Germany
- Equipe Labellisée La Ligue, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de Santé et de Recherche Médicale (INSERM) U964/Centre National de Recherche Scientifique (CNRS) UMR 7104/Université de Strasbourg, 67404 Illkirch, France
- Corresponding authors.E-mail E-mail .
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47
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Janas MM, Khaled M, Schubert S, Bernstein JG, Golan D, Veguilla RA, Fisher DE, Shomron N, Levy C, Novina CD. Feed-forward microprocessing and splicing activities at a microRNA-containing intron. PLoS Genet 2011; 7:e1002330. [PMID: 22028668 PMCID: PMC3197686 DOI: 10.1371/journal.pgen.1002330] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 08/16/2011] [Indexed: 01/03/2023] Open
Abstract
The majority of mammalian microRNA (miRNA) genes reside within introns of protein-encoding and non-coding genes, yet the mechanisms coordinating primary transcript processing into both mature miRNA and spliced mRNA are poorly understood. Analysis of melanoma invasion suppressor miR-211 expressed from intron 6 of melastatin revealed that microprocessing of miR-211 promotes splicing of the exon 6–exon 7 junction of melastatin by a mechanism requiring the RNase III activity of Drosha. Additionally, mutations in the 5′ splice site (5′SS), but not in the 3′SS, branch point, or polypyrimidine tract of intron 6 reduced miR-211 biogenesis and Drosha recruitment to intron 6, indicating that 5′SS recognition by the spliceosome promotes microprocessing of miR-211. Globally, knockdown of U1 splicing factors reduced intronic miRNA expression. Our data demonstrate novel mutually-cooperative microprocessing and splicing activities at an intronic miRNA locus and suggest that the initiation of spliceosome assembly may promote microprocessing of intronic miRNAs. MicroRNA (miRNA) genes are transcribed as long primary RNAs containing local hairpins that are excised by the Microprocessor complex minimally composed of Drosha and DGCR8. Most mammalian miRNAs reside in introns of protein-encoding and non-coding genes, but it is unclear how microprocessing of an intronic miRNA and splicing at the host gene intron affect each other. We recently reported that in melanoma, a miRNA expressed from intron 6 of melastatin (miR-211) assumes the tumor suppressive function of its host gene. In our current work, we detected elevated melastatin exon 6–exon 7 junctions relative to other exon-exon junctions that lack intronic miRNAs, suggesting that microprocessing promotes splicing. We show that microprocessing of miR-211 precedes completion of splicing of the exon 6–exon 7 junctions and that Drosha's endonuclease activity is required to facilitate exon 6–exon 7 junction formation. Additionally, we found that the first step of spliceosome assembly, recognition of the 5′ splice site by the U1 snRNP complex, promotes microprocessing of miR-211 and other intronic but not intergenic miRNAs. Our findings reveal a mutually cooperative, physical, and functional coupling of intronic miRNA biogenesis and splicing at the host intron, and they suggest a global positive effect of spliceosome assembly on intronic miRNA microprocessing.
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Affiliation(s)
- Maja M. Janas
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
| | - Mehdi Khaled
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
- Cutaneous Biology Research Center, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Steffen Schubert
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
| | - Jacob G. Bernstein
- MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - David Golan
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rosa A. Veguilla
- Cutaneous Biology Research Center, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - David E. Fisher
- Cutaneous Biology Research Center, Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Noam Shomron
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Carmit Levy
- Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (CL); (CDN)
| | - Carl D. Novina
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, United States of America
- * E-mail: (CL); (CDN)
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48
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Bragulat M, Meyer M, Macías S, Camats M, Labrador M, Vilardell J. RPL30 regulation of splicing reveals distinct roles for Cbp80 in U1 and U2 snRNP cotranscriptional recruitment. RNA 2010; 16:2033-41. [PMID: 20801768 PMCID: PMC2941111 DOI: 10.1261/rna.2366310] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Pre-mRNA splicing is catalyzed by the spliceosome, and its control is essential for correct gene expression. While splicing repressors typically interfere with transcript recognition by spliceosomal components, the yeast protein L30 blocks spliceosomal rearrangements required for the engagement of U2 snRNP (small ribonucleoprotein particle) to its own transcript RPL30. Using a mutation in the RPL30 binding site that disrupts this repression, we have taken a genetic approach to reveal that regulation of splicing is restored in this mutant by deletion of the cap-binding complex (CBC) component Cbp80. Indeed, our data indicate that Cbp80 plays distinct roles in the recognition of the intron by U1 and U2 snRNP. It promotes the initial 5' splice site recognition by U1 and, independently, facilitates U2 recruitment, depending on sequences located in the vicinity of the 5' splice site. These results reveal a novel function for CBC in splicing and imply that these molecular events can be the target of a splicing regulator.
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Qin F, Chen Y, Wu M, Li Y, Zhang J, Chen HF. Induced fit or conformational selection for RNA/U1A folding. RNA 2010; 16:1053-1061. [PMID: 20354153 PMCID: PMC2856877 DOI: 10.1261/rna.2008110] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 02/07/2010] [Indexed: 05/29/2023]
Abstract
The hairpin II of U1 snRNA can bind U1A protein with high affinity and specificity. NMR spectra suggest that the loop region of apo-RNA is largely unstructured and undergoes a transition from unstructured to well-folded upon U1Abinding. However, the mechanism that RNA folding coupled protein binding is poorly understood. To get an insight into the mechanism, we have performed explicit-solvent molecular dynamics (MD) to study the folding kinetics of bound RNA and apo-RNA. Room-temperature MD simulations suggest that the conformation of bound RNA has significant adjustment and becomes more stable upon U1A binding. Kinetic analysis of high-temperature MD simulations shows that bound RNA and apo-RNA unfold via a two-state process, respectively. Both kinetics and free energy landscape analyses indicate that bound RNA folds in the order of RNA contracting, U1A binding, and tertiary folding. The predicted Phi-values suggest that A8, C10, A11, and G16 are key bases for bound RNA folding. Mutant Arg52Gln analysis shows that electrostatic interaction and hydrogen bonds between RNA and U1A (Arg52Gln) decrease. These results are in qualitative agreement with experiments. Furthermore, this method could be used in other studies about biomolecule folding upon receptor binding.
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Affiliation(s)
- Fang Qin
- College of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai, 200240, China
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Johnson ML, Nagengast AA, Salz HK. PPS, a large multidomain protein, functions with sex-lethal to regulate alternative splicing in Drosophila. PLoS Genet 2010; 6:e1000872. [PMID: 20221253 PMCID: PMC2832672 DOI: 10.1371/journal.pgen.1000872] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Accepted: 02/03/2010] [Indexed: 12/25/2022] Open
Abstract
Alternative splicing controls the expression of many genes, including the Drosophila sex determination gene Sex-lethal (Sxl). Sxl expression is controlled via a negative regulatory mechanism where inclusion of the translation-terminating male exon is blocked in females. Previous studies have shown that the mechanism leading to exon skipping is autoregulatory and requires the SXL protein to antagonize exon inclusion by interacting with core spliceosomal proteins, including the U1 snRNP protein Sans-fille (SNF). In studies begun by screening for proteins that interact with SNF, we identified PPS, a previously uncharacterized protein, as a novel component of the machinery required for Sxl male exon skipping. PPS encodes a large protein with four signature motifs, PHD, BRK, TFS2M, and SPOC, typically found in proteins involved in transcription. We demonstrate that PPS has a direct role in Sxl male exon skipping by showing first that loss of function mutations have phenotypes indicative of Sxl misregulation and second that the PPS protein forms a complex with SXL and the unspliced Sxl RNA. In addition, we mapped the recruitment of PPS, SXL, and SNF along the Sxl gene using chromatin immunoprecipitation (ChIP), which revealed that, like many other splicing factors, these proteins bind their RNA targets while in close proximity to the DNA. Interestingly, while SNF and SXL are specifically recruited to their predicted binding sites, PPS has a distinct pattern of accumulation along the Sxl gene, associating with a region that includes, but is not limited to, the SxlPm promoter. Together, these data indicate that PPS is different from other splicing factors involved in male-exon skipping and suggest, for the first time, a functional link between transcription and SXL-mediated alternative splicing. Loss of zygotic PPS function, however, is lethal to both sexes, indicating that its role may be of broad significance.
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Affiliation(s)
- Matthew L. Johnson
- Department of Genetics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, United States of America
| | - Alexis A. Nagengast
- Department of Genetics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, United States of America
| | - Helen K. Salz
- Department of Genetics, Case Western Reserve University, School of Medicine, Cleveland, Ohio, United States of America
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