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Abrhámová K, Groušlová M, Valentová A, Hao X, Liu B, Převorovský M, Gahura O, Půta F, Sunnerhagen P, Folk P. Truncating the spliceosomal 'rope protein' Prp45 results in Htz1 dependent phenotypes. RNA Biol 2024; 21:1-17. [PMID: 38711165 PMCID: PMC11085953 DOI: 10.1080/15476286.2024.2348896] [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] [Accepted: 04/24/2024] [Indexed: 05/08/2024] Open
Abstract
Spliceosome assembly contributes an important but incompletely understood aspect of splicing regulation. Prp45 is a yeast splicing factor which runs as an extended fold through the spliceosome, and which may be important for bringing its components together. We performed a whole genome analysis of the genetic interaction network of the truncated allele of PRP45 (prp45(1-169)) using synthetic genetic array technology and found chromatin remodellers and modifiers as an enriched category. In agreement with related studies, H2A.Z-encoding HTZ1, and the components of SWR1, INO80, and SAGA complexes represented prominent interactors, with htz1 conferring the strongest growth defect. Because the truncation of Prp45 disproportionately affected low copy number transcripts of intron-containing genes, we prepared strains carrying intronless versions of SRB2, VPS75, or HRB1, the most affected cases with transcription-related function. Intron removal from SRB2, but not from the other genes, partly repaired some but not all the growth phenotypes identified in the genetic screen. The interaction of prp45(1-169) and htz1Δ was detectable even in cells with SRB2 intron deleted (srb2Δi). The less truncated variant, prp45(1-330), had a synthetic growth defect with htz1Δ at 16°C, which also persisted in the srb2Δi background. Moreover, htz1Δ enhanced prp45(1-330) dependent pre-mRNA hyper-accumulation of both high and low efficiency splicers, genes ECM33 and COF1, respectively. We conclude that while the expression defects of low expression intron-containing genes contribute to the genetic interactome of prp45(1-169), the genetic interactions between prp45 and htz1 alleles demonstrate the sensitivity of spliceosome assembly, delayed in prp45(1-169), to the chromatin environment.
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Affiliation(s)
- Kateřina Abrhámová
- Department of Cell Biology, Faculty of Science, Charles University, Praha, Czech Republic
| | - Martina Groušlová
- Department of Cell Biology, Faculty of Science, Charles University, Praha, Czech Republic
| | - Anna Valentová
- Department of Cell Biology, Faculty of Science, Charles University, Praha, Czech Republic
| | - Xinxin Hao
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Beidong Liu
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, Praha, Czech Republic
| | - Ondřej Gahura
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - František Půta
- Department of Cell Biology, Faculty of Science, Charles University, Praha, Czech Republic
| | - Per Sunnerhagen
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Petr Folk
- Department of Cell Biology, Faculty of Science, Charles University, Praha, Czech Republic
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2
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Jian Y, Chen X, Sun K, Liu Z, Cheng D, Cao J, Liu J, Cheng X, Wu L, Zhang F, Luo Y, Hahn M, Ma Z, Yin Y. SUMOylation regulates pre-mRNA splicing to overcome DNA damage in fungi. New Phytol 2023; 237:2298-2315. [PMID: 36539920 DOI: 10.1111/nph.18692] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 10/14/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Pathogenic fungi are subject to DNA damage stress derived from host immune responses during infection. Small ubiquitin-like modifier (SUMO) modification and precursor (pre)-mRNA splicing are both involved in DNA damage response (DDR). However, the mechanisms of how SUMOylation and splicing coordinated in DDR remain largely unknown. Combining with biochemical analysis, RNA-Seq method, and biological analysis, we report that SUMO pathway participates in DDR and virulence in Fusarium graminearum, a causal agent of Fusarium head blight of cereal crops world-wide. Interestingly, a key transcription factor FgSR is SUMOylated upon DNA damage stress. SUMOylation regulates FgSR nuclear-cytoplasmic partitioning and its phosphorylation by FgMec1, and promotes its interaction with chromatin remodeling complex SWI/SNF for activating the expression of DDR-related genes. Moreover, the SWI/SNF complex was found to further recruit splicing-related NineTeen Complex, subsequently modulates pre-mRNA splicing during DDR. Our findings reveal a novel function of SUMOylation in DDR by regulating a transcription factor to orchestrate gene expression and pre-mRNA splicing to overcome DNA damage during the infection of F. graminearum, which advances the understanding of the delicate regulation of DDR by SUMOylation in pathogenic fungi, and extends the knowledge of cooperation of SUMOylation and pre-mRNA splicing in DDR in eukaryotes.
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Affiliation(s)
- Yunqing Jian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Xia Chen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Kewei Sun
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Zunyong Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Danni Cheng
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Jie Cao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Jianzhao Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Xiaofei Cheng
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030, China
| | - Liang Wu
- Institute of Crop Science, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Feng Zhang
- Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuming Luo
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Matthias Hahn
- Department of Biology, University of Kaiserslautern, PO Box 3049, 67653, Kaiserslautern, Germany
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yanni Yin
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
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3
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Casteels T, Bajew S, Reiniš J, Enders L, Schuster M, Fontaine F, Müller AC, Wagner BK, Bock C, Kubicek S. SMNDC1 links chromatin remodeling and splicing to regulate pancreatic hormone expression. Cell Rep 2022; 40:111288. [PMID: 36044849 DOI: 10.1016/j.celrep.2022.111288] [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: 09/03/2021] [Revised: 04/06/2022] [Accepted: 08/09/2022] [Indexed: 11/28/2022] Open
Abstract
Insulin expression is primarily restricted to the pancreatic β cells, which are physically or functionally depleted in diabetes. Identifying targetable pathways repressing insulin in non-β cells, particularly in the developmentally related glucagon-secreting α cells, is an important aim of regenerative medicine. Here, we perform an RNA interference screen in a murine α cell line to identify silencers of insulin expression. We discover that knockdown of the splicing factor Smndc1 triggers a global repression of α cell gene-expression programs in favor of increased β cell markers. Mechanistically, Smndc1 knockdown upregulates the β cell transcription factor Pdx1 by modulating the activities of the BAF and Atrx chromatin remodeling complexes. SMNDC1's repressive role is conserved in human pancreatic islets, its loss triggering enhanced insulin secretion and PDX1 expression. Our study identifies Smndc1 as a key factor connecting splicing and chromatin remodeling to the control of insulin expression in human and mouse islet cells.
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Affiliation(s)
- Tamara Casteels
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Simon Bajew
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Carrer del Dr. Aiguader 88, 08003 Barcelona, Spain; Universitat Pompeu Fabra, Carrer del Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Jiří Reiniš
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Lennart Enders
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Michael Schuster
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - Frédéric Fontaine
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | - André C Müller
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria
| | | | - Christoph Bock
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria; Medical University of Vienna, Center for Medical Statistics, Informatics, and Intelligent Systems, Institute of Artificial Intelligence, 1090 Vienna, Austria
| | - Stefan Kubicek
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, 1090 Vienna, Austria.
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4
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Jian Y, Shim WB, Ma Z. Multiple functions of SWI/SNF chromatin remodeling complex in plant-pathogen interactions. Stress Biol 2021; 1:18. [PMID: 37676626 PMCID: PMC10442046 DOI: 10.1007/s44154-021-00019-w] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 11/22/2021] [Indexed: 09/08/2023]
Abstract
The SWI/SNF chromatin remodeling complex utilizes the energy of ATP hydrolysis to facilitate chromatin access and plays essential roles in DNA-based events. Studies in animals, plants and fungi have uncovered sophisticated regulatory mechanisms of this complex that govern development and various stress responses. In this review, we summarize the composition of SWI/SNF complex in eukaryotes and discuss multiple functions of the SWI/SNF complex in regulating gene transcription, mRNA splicing, and DNA damage response. Our review further highlights the importance of SWI/SNF complex in regulating plant immunity responses and fungal pathogenesis. Finally, the potentials in exploiting chromatin remodeling for management of crop disease are presented.
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Affiliation(s)
- Yunqing Jian
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Won-Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China.
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5
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West KO, Scott HM, Torres-Odio S, West AP, Patrick KL, Watson RO. The Splicing Factor hnRNP M Is a Critical Regulator of Innate Immune Gene Expression in Macrophages. Cell Rep 2020; 29:1594-1609.e5. [PMID: 31693898 PMCID: PMC6981299 DOI: 10.1016/j.celrep.2019.09.078] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/13/2019] [Accepted: 09/26/2019] [Indexed: 12/16/2022] Open
Abstract
While transcriptional control of innate immune gene expression is well characterized, almost nothing is known about how pre-mRNA splicing decisions influence, or are influenced by, macrophage activation. Here, we demonstrate that the splicing factor hnRNP M is a critical repressor of innate immune gene expression and that its function is regulated by pathogen sensing cascades. Loss of hnRNP M led to hyperinduction of a unique regulon of inflammatory and antimicrobial genes following diverse innate immune stimuli. While mutating specific serines on hnRNP M had little effect on its ability to control pre-mRNA splicing or transcript levels of housekeeping genes in resting macrophages, it greatly impacted the protein’s ability to dampen induction of specific innate immune transcripts following pathogen sensing. These data reveal a previously unappreciated role for pattern recognition receptor signaling in controlling splicing factor phosphorylation and establish pre-mRNA splicing as a critical regulatory node in defining innate immune outcomes. West et al. report that hnRNP M represses expression of a cohort of innate immune transcripts in infected macrophages. IL6 splicing repression is relieved when hnRNP M is phosphorylated at specific residues, demonstrating that post-translational modification of splicing factors downstream of pathogen sensing can control maturation of innate immune mRNAs.
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Affiliation(s)
- Kelsi O West
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Haley M Scott
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Sylvia Torres-Odio
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - A Phillip West
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Kristin L Patrick
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA.
| | - Robert O Watson
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA.
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6
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Abstract
At each active protein-encoding gene, nascent RNA is tethered to the DNA axis by elongating RNA polymerase II (Pol II) and is continuously altered by splicing and other processing events during its synthesis. This review discusses the development of three major methods that enable us to track the conversion of precursor messenger RNA (pre-mRNA) to messenger RNA (mRNA) products in vivo: live-cell imaging, metabolic labeling of RNA, and RNA-seq of purified nascent RNA. These approaches are complementary, addressing distinct issues of transcription rates and intron lifetimes alongside spatial information regarding the gene position of Pol II at which spliceosomes act. The findings will be placed in the context of active transcription units, each of which-because of the presence of nascent RNA, Pol II, and features of the chromatin environment-will recruit a potentially gene-specific constellation of RNA binding proteins and processing machineries.
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Affiliation(s)
- Karla M Neugebauer
- Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
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7
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Yu X, Meng X, Liu Y, Wang X, Wang TJ, Zhang A, Li N, Qi X, Liu B, Xu ZY. The chromatin remodeler ZmCHB101 impacts alternative splicing contexts in response to osmotic stress. Plant Cell Rep 2019; 38:131-145. [PMID: 30443733 DOI: 10.1007/s00299-018-2354-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 11/07/2018] [Indexed: 05/16/2023]
Abstract
Maize SWI3-type chromatin remodeler impacts alternative splicing contexts in response to osmotic stress by altering nucleosome density and affecting transcriptional elongation rate. Alternative splicing (AS) is commonly found in higher eukaryotes and is an important posttranscriptional regulatory mechanism to generate transcript diversity. AS has been widely accepted as playing essential roles in different biological processes including growth, development, signal transduction and responses to biotic and abiotic stresses in plants. However, whether and how chromatin remodeling complex functions in AS in plant under osmotic stress remains unknown. Here, we show that a maize SWI3D protein, ZmCHB101, impacts AS contexts in response to osmotic stress. Genome-wide analysis of mRNA contexts in response to osmotic stress using ZmCHB101-RNAi lines reveals that ZmCHB101 impacts alternative splicing contexts of a subset of osmotic stress-responsive genes. Intriguingly, ZmCHB101-mediated regulation of gene expression and AS is largely uncoupled, pointing to diverse molecular functions of ZmCHB101 in transcriptional and posttranscriptional regulation. We further found ZmCHB101 impacts the alternative splicing contexts by influencing alteration of chromatin and histone modification status as well as transcriptional elongation rates mediated by RNA polymerase II. Taken together, our findings suggest a novel insight of how plant chromatin remodeling complex impacts AS under osmotic stress .
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Affiliation(s)
- Xiaoming Yu
- School of Agronomy, Jilin Agricultural Science and Technology University, Jilin, 132301, People's Republic of China
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Xinchao Meng
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Yutong Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Xutong Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
- Department of Agronomy, Purdue University, West Lafayette, USA
| | - Tian-Jing Wang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Ai Zhang
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Ning Li
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China
| | - Xin Qi
- Department of Agronomy, Jilin Agricultural University, Changchun, 130118, People's Republic of China
| | - Bao Liu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China.
| | - Zheng-Yi Xu
- Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun, 130024, People's Republic of China.
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8
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Abstract
Eukaryotic gene expression requires the cumulative activity of multiple molecular machines to synthesize and process newly transcribed pre-messenger RNA. Introns, the noncoding regions in pre-mRNA, must be removed by the spliceosome, which assembles on the pre-mRNA as it is transcribed by RNA polymerase II (Pol II). The assembly and activity of the spliceosome can be modulated by features including the speed of transcription elongation, chromatin, post-translational modifications of Pol II and histone tails, and other RNA processing events like 5'-end capping. Here, we review recent work that has revealed cooperation and coordination among co-transcriptional processing events and speculate on new avenues of research. We anticipate new mechanistic insights capable of unraveling the relative contribution of coupled processing to gene expression.
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Affiliation(s)
- Tucker J Carrocci
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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9
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Patrick KL, Wojcechowskyj JA, Bell SL, Riba MN, Jing T, Talmage S, Xu P, Cabello AL, Xu J, Shales M, Jimenez-Morales D, Ficht TA, de Figueiredo P, Samuel JE, Li P, Krogan NJ, Watson RO. Quantitative Yeast Genetic Interaction Profiling of Bacterial Effector Proteins Uncovers a Role for the Human Retromer in Salmonella Infection. Cell Syst 2018; 7:323-338.e6. [PMID: 30077634 DOI: 10.1016/j.cels.2018.06.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/21/2018] [Accepted: 06/21/2018] [Indexed: 11/26/2022]
Abstract
Intracellular bacterial pathogens secrete a repertoire of effector proteins into host cells that are required to hijack cellular pathways and cause disease. Despite decades of research, the molecular functions of most bacterial effectors remain unclear. To address this gap, we generated quantitative genetic interaction profiles between 36 validated and putative effectors from three evolutionarily divergent human bacterial pathogens and 4,190 yeast deletion strains. Correlating effector-generated profiles with those of yeast mutants, we recapitulated known biology for several effectors with remarkable specificity and predicted previously unknown functions for others. Biochemical and functional validation in human cells revealed a role for an uncharacterized component of the Salmonella SPI-2 translocon, SseC, in regulating maintenance of the Salmonella vacuole through interactions with components of the host retromer complex. These results exhibit the power of genetic interaction profiling to discover and dissect complex biology at the host-pathogen interface.
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Affiliation(s)
- Kristin L Patrick
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA
| | - Jason A Wojcechowskyj
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA 94158, USA; J. David Gladstone Institute, San Francisco, CA 94158, USA
| | - Samantha L Bell
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA
| | - Morgan N Riba
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA
| | - Tao Jing
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Sara Talmage
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA
| | - Pengbiao Xu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Ana L Cabello
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA; Department of Veterinary Pathobiology, Texas A&M College of Veterinary Medicine and Biomedical Sciences, College Station, TX 77843, USA; Norman Borlaug Center, Texas A&M University, College Station, TX 77843, USA
| | - Jiewei Xu
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA 94158, USA
| | - Michael Shales
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA 94158, USA
| | - David Jimenez-Morales
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA 94158, USA; J. David Gladstone Institute, San Francisco, CA 94158, USA
| | - Thomas A Ficht
- Department of Veterinary Pathobiology, Texas A&M College of Veterinary Medicine and Biomedical Sciences, College Station, TX 77843, USA
| | - Paul de Figueiredo
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA; Department of Veterinary Pathobiology, Texas A&M College of Veterinary Medicine and Biomedical Sciences, College Station, TX 77843, USA; Norman Borlaug Center, Texas A&M University, College Station, TX 77843, USA
| | - James E Samuel
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA
| | - Pingwei Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA; Quantitative Biosciences Institute (QBI), University of California, San Francisco, CA 94158, USA; J. David Gladstone Institute, San Francisco, CA 94158, USA.
| | - Robert O Watson
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX 77802, USA.
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10
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Herzel L, Straube K, Neugebauer KM. Long-read sequencing of nascent RNA reveals coupling among RNA processing events. Genome Res 2018; 28:1008-1019. [PMID: 29903723 PMCID: PMC6028129 DOI: 10.1101/gr.232025.117] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/24/2018] [Indexed: 12/13/2022]
Abstract
Pre-mRNA splicing is accomplished by the spliceosome, a megadalton complex that assembles de novo on each intron. Because spliceosome assembly and catalysis occur cotranscriptionally, we hypothesized that introns are removed in the order of their transcription in genomes dominated by constitutive splicing. Remarkably little is known about splicing order and the regulatory potential of nascent transcript remodeling by splicing, due to the limitations of existing methods that focus on analysis of mature splicing products (mRNAs) rather than substrates and intermediates. Here, we overcome this obstacle through long-read RNA sequencing of nascent, multi-intron transcripts in the fission yeast Schizosaccharomyces pombe. Most multi-intron transcripts were fully spliced, consistent with rapid cotranscriptional splicing. However, an unexpectedly high proportion of transcripts were either fully spliced or fully unspliced, suggesting that splicing of any given intron is dependent on the splicing status of other introns in the transcript. Supporting this, mild inhibition of splicing by a temperature-sensitive mutation in prp2, the homolog of vertebrate U2AF65, increased the frequency of fully unspliced transcripts. Importantly, fully unspliced transcripts displayed transcriptional read-through at the polyA site and were degraded cotranscriptionally by the nuclear exosome. Finally, we show that cellular mRNA levels were reduced in genes with a high number of unspliced nascent transcripts during caffeine treatment, showing regulatory significance of cotranscriptional splicing. Therefore, overall splicing of individual nascent transcripts, 3′ end formation, and mRNA half-life depend on the splicing status of neighboring introns, suggesting crosstalk among spliceosomes and the polyA cleavage machinery during transcription elongation.
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Affiliation(s)
- Lydia Herzel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Korinna Straube
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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11
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Venkataramanan S, Douglass S, Galivanche AR, Johnson TL. The chromatin remodeling complex Swi/Snf regulates splicing of meiotic transcripts in Saccharomyces cerevisiae. Nucleic Acids Res 2017. [PMID: 28637241 PMCID: PMC5570110 DOI: 10.1093/nar/gkx373] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Despite its relatively streamlined genome, there are important examples of regulated RNA splicing in Saccharomyces cerevisiae, such as splicing of meiotic transcripts. Like other eukaryotes, S. cerevisiae undergoes a dramatic reprogramming of gene expression during meiosis, including regulated splicing of a number of crucial meiosis-specific RNAs. Splicing of a subset of these is dependent upon the splicing activator Mer1. Here we show a crucial role for the chromatin remodeler Swi/Snf in regulation of splicing of meiotic genes and find that the complex affects meiotic splicing in two ways. First, we show that Swi/Snf regulates nutrient-dependent downregulation of ribosomal protein encoding RNAs, leading to the redistribution of spliceosomes from this abundant class of intron-containing RNAs (the ribosomal protein genes) to Mer1-regulated transcripts. We also demonstrate that Mer1 expression is dependent on Snf2, its acetylation state and histone H3 lysine 9 acetylation at the MER1 locus. Hence, Snf2 exerts systems level control of meiotic gene expression through two temporally distinct mechanisms, demonstrating that it is a key regulator of meiotic splicing in S. cerevisiae. We also reveal an evolutionarily conserved mechanism whereby the cell redirects its energy from maintaining its translational capacity to the process of meiosis.
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Affiliation(s)
- Srivats Venkataramanan
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095, USA.,Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
| | - Stephen Douglass
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095, USA.,Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
| | - Anoop R Galivanche
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095, USA.,Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
| | - Tracy L Johnson
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095, USA.,Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
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12
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Nissen KE, Homer CM, Ryan CJ, Shales M, Krogan NJ, Patrick KL, Guthrie C. The histone variant H2A.Z promotes splicing of weak introns. Genes Dev 2017; 31:688-701. [PMID: 28446597 PMCID: PMC5411709 DOI: 10.1101/gad.295287.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/22/2017] [Indexed: 12/12/2022]
Abstract
In this study, Nissen et al. investigated the function of the highly conserved histone variant H2A.Z in pre-mRNA splicing using the intron-rich model yeast S. pombe. The findings suggest that H2A.Z occupancy promotes cotranscriptional splicing of suboptimal introns that may otherwise be discarded via proofreading ATPases. Multiple lines of evidence implicate chromatin in the regulation of premessenger RNA (pre-mRNA) splicing. However, the influence of chromatin factors on cotranscriptional splice site usage remains unclear. Here we investigated the function of the highly conserved histone variant H2A.Z in pre-mRNA splicing using the intron-rich model yeast Schizosaccharomyces pombe. Using epistatic miniarray profiles (EMAPs) to survey the genetic interaction landscape of the Swr1 nucleosome remodeling complex, which deposits H2A.Z, we uncovered evidence for functional interactions with components of the spliceosome. In support of these genetic connections, splicing-specific microarrays show that H2A.Z and the Swr1 ATPase are required during temperature stress for the efficient splicing of a subset of introns. Notably, affected introns are enriched for H2A.Z occupancy and more likely to contain nonconsensus splice sites. To test the significance of the latter correlation, we mutated the splice sites in an affected intron to consensus and found that this suppressed the requirement for H2A.Z in splicing of that intron. These data suggest that H2A.Z occupancy promotes cotranscriptional splicing of suboptimal introns that may otherwise be discarded via proofreading ATPases. Consistent with this model, we show that overexpression of splicing ATPase Prp16 suppresses both the growth and splicing defects seen in the absence of H2A.Z.
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Affiliation(s)
- Kelly E Nissen
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco 94158, California, USA
| | - Christina M Homer
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco 94158, California, USA
| | - Colm J Ryan
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland
| | - Michael Shales
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco 94158, California, USA.,California Institute for Quantitative Biosciences (QB3), San Francisco 94158, California, USA
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco 94158, California, USA.,California Institute for Quantitative Biosciences (QB3), San Francisco 94158, California, USA.,J. David Gladstone Institutes, San Francisco 94158, California, USA
| | - Kristin L Patrick
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco 94158, California, USA.,Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, Texas 77807, USA
| | - Christine Guthrie
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco 94158, California, USA
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13
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Abstract
Alternative splicing represents an important level of the regulation of gene function in eukaryotic organisms. It plays a critical role in virtually every biological process within an organism, including regulation of cell division and cell death, differentiation of tissues in the embryo and the adult organism, as well as in cellular response to diverse environmental factors. In turn, studies of the last decade have shown that alternative splicing itself is controlled by different mechanisms. Unfortunately, there is no clear understanding of how these diverse mechanisms, or determinants, regulate and constrain the set of alternative RNA species produced from any particular gene in every cell of the human body. Here, we provide a consolidated overview of alternative splicing determinants including RNA-protein interactions, epigenetic regulation via chromatin remodeling, coupling of transcription-to-alternative splicing, effect of secondary structures in pre-RNA, and function of the RNA quality control systems. We also extensively and critically discuss some mechanistic insights on coordinated inclusion/exclusion of exons during the formation of mature RNA molecules. We conclude that the final structure of RNA is pre-determined by a complex interplay between cis- and trans-acting factors. Altogether, currently available empirical data significantly expand our understanding of the functioning of the alternative splicing machinery of cells in normal and pathological conditions. On the other hand, there are still many blind spots that require further deep investigations.
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14
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Alpert T, Herzel L, Neugebauer KM. Perfect timing: splicing and transcription rates in living cells. Wiley Interdiscip Rev RNA 2016; 8. [PMID: 27873472 DOI: 10.1002/wrna.1401] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/12/2016] [Accepted: 09/26/2016] [Indexed: 12/27/2022]
Abstract
An important step toward understanding gene regulation is the elucidation of the time necessary for the completion of individual steps. Measurement of reaction rates can reveal potential nodes for regulation. For example, measurements of in vivo transcription elongation rates reveal regulation by DNA sequence, gene architecture, and chromatin. Pre-mRNA splicing is regulated by transcription elongation rates and vice versa, yet the rates of RNA processing reactions remain largely elusive. Since the 1980s, numerous model systems and approaches have been used to determine the precise timing of splicing in vivo. Because splicing can be co-transcriptional, the position of Pol II when splicing is detected has been used as a proxy for time by some investigators. In addition to these 'distance-based' measurements, 'time-based' measurements have been possible through live cell imaging, metabolic labeling of RNA, and gene induction. Yet splicing rates can be convolved by the time it takes for transcription, spliceosome assembly and spliceosome disassembly. The variety of assays and systems used has, perhaps not surprisingly, led to reports of widely differing splicing rates in vivo. Recently, single molecule RNA-seq has indicated that splicing occurs more quickly than previously deduced. Here we comprehensively review these findings and discuss evidence that splicing and transcription rates are closely coordinated, facilitating the efficiency of gene expression. On the other hand, introduction of splicing delays through as yet unknown mechanisms provide opportunity for regulation. More work is needed to understand how cells optimize the rates of gene expression for a range of biological conditions. WIREs RNA 2017, 8:e1401. doi: 10.1002/wrna.1401 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Tara Alpert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Lydia Herzel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
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15
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Vijaykrishna N, Melangath G, Kumar R, Khandelia P, Bawa P, Varadarajan R, Vijayraghavan U. The Fission Yeast Pre-mRNA-processing Factor 18 (prp18+) Has Intron-specific Splicing Functions with Links to G1-S Cell Cycle Progression. J Biol Chem 2016; 291:27387-27402. [PMID: 27875300 DOI: 10.1074/jbc.m116.751289] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/11/2016] [Indexed: 12/24/2022] Open
Abstract
The fission yeast genome, which contains numerous short introns, is an apt model for studies on fungal splicing mechanisms and splicing by intron definition. Here we perform a domain analysis of the evolutionarily conserved Schizosaccharomyces pombe pre-mRNA-processing factor, SpPrp18. Our mutational and biophysical analyses of the C-terminal α-helical bundle reveal critical roles for the conserved region as well as helix five. We generate a novel conditional missense mutant, spprp18-5 To assess the role of SpPrp18, we performed global splicing analyses on cells depleted of prp18+ and the conditional spprp18-5 mutant, which show widespread but intron-specific defects. In the absence of functional SpPrp18, primer extension analyses on a tfIId+ intron 1-containing minitranscript show accumulated pre-mRNA, whereas the lariat intron-exon 2 splicing intermediate was undetectable. These phenotypes also occurred in cells lacking both SpPrp18 and SpDbr1 (lariat debranching enzyme), a genetic background suitable for detection of lariat RNAs. These data indicate a major precatalytic splicing arrest that is corroborated by the genetic interaction between spprp18-5 and spprp2-1, a mutant in the early acting U2AF59 protein. Interestingly, SpPrp18 depletion caused cell cycle arrest before S phase. The compromised splicing of transcripts coding for G1-S regulators, such as Res2, a transcription factor, and Skp1, a regulated proteolysis factor, are shown. The cumulative effects of SpPrp18-dependent intron splicing partly explain the G1 arrest upon the loss of SpPrp18. Our study using conditional depletion of spprp18+ and the spprp18-5 mutant uncovers an intron-specific splicing function and early spliceosomal interactions and suggests links with cell cycle progression.
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Affiliation(s)
| | | | - Rakesh Kumar
- From the Department of Microbiology and Cell Biology and
| | | | | | - Raghavan Varadarajan
- the Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
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16
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Allemand E, Myers MP, Garcia-Bernardo J, Harel-Bellan A, Krainer AR, Muchardt C. A Broad Set of Chromatin Factors Influences Splicing. PLoS Genet 2016; 12:e1006318. [PMID: 27662573 DOI: 10.1371/journal.pgen.1006318] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 08/23/2016] [Indexed: 01/21/2023] Open
Abstract
Several studies propose an influence of chromatin on pre-mRNA splicing, but it is still unclear how widespread and how direct this phenomenon is. We find here that when assembled in vivo, the U2 snRNP co-purifies with a subset of chromatin-proteins, including histones and remodeling complexes like SWI/SNF. Yet, an unbiased RNAi screen revealed that the outcome of splicing is influenced by a much larger variety of chromatin factors not all associating with the spliceosome. The availability of this broad range of chromatin factors impacting splicing further unveiled their very context specific effect, resulting in either inclusion or skipping, depending on the exon under scrutiny. Finally, a direct assessment of the impact of chromatin on splicing using an in vitro co-transcriptional splicing assay with pre-mRNAs transcribed from a nucleosomal template, demonstrated that chromatin impacts nascent pre-mRNP in their competence for splicing. Altogether, our data show that numerous chromatin factors associated or not with the spliceosome can affect the outcome of splicing, possibly as a function of the local chromatin environment that by default interferes with the efficiency of splicing. Splicing is an RNA editing step allowing to produce multiple transcripts from a single gene. The gene itself is organized in chromatin, associating DNA and multiple proteins. Some proteins regulating the compaction of the chromatin also affect RNA splicing. Yet, it was unclear whether these chromatin proteins were exceptions or whether chromatin very generally affected the outcome of splicing. Here, we show that a subset of chromatin proteins is physically in interaction with the enzyme responsible for RNA splicing. In addition, several chromatin proteins not found directly associated with the splicing machinery were also able to influence RNA splicing, suggesting that chromatin compaction very globally plays a role in splicing. This finding was confirmed using the first in vitro assay combining transcription and splicing in the context of chromatin; this assay showed that assembling DNA with chromatin proteins influences the efficiency of splicing.
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17
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Fair BJ, Pleiss JA. The power of fission: yeast as a tool for understanding complex splicing. Curr Genet 2016; 63:375-380. [PMID: 27628706 DOI: 10.1007/s00294-016-0647-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 08/29/2016] [Accepted: 08/31/2016] [Indexed: 01/12/2023]
Abstract
Pre-mRNA splicing is an essential component of eukaryotic gene expression. Many metazoans, including humans, regulate alternative splicing patterns to generate expansions of their proteome from a limited number of genes. Importantly, a considerable fraction of human disease causing mutations manifest themselves through altering the sequences that shape the splicing patterns of genes. Thus, understanding the mechanistic bases of this complex pathway will be an essential component of combating these diseases. Dating almost to the initial discovery of splicing, researchers have taken advantage of the genetic tractability of budding yeast to identify the components and decipher the mechanisms of splicing. However, budding yeast lacks the complex splicing machinery and alternative splicing patterns most relevant to humans. More recently, many researchers have turned their efforts to study the fission yeast, Schizosaccharomyces pombe, which has retained many features of complex splicing, including degenerate splice site sequences, the usage of exonic splicing enhancers, and SR proteins. Here, we review recent work using fission yeast genetics to examine pre-mRNA splicing, highlighting its promise for modeling the complex splicing seen in higher eukaryotes.
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Affiliation(s)
- Benjamin Jung Fair
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Jeffrey A Pleiss
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.
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18
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Abstract
During the last decade, a host of epigenetic mechanisms were found to contribute to cancer and other human diseases. Several genomic studies have revealed that ∼20% of malignancies have alterations of the subunits of polymorphic BRG-/BRM-associated factor (BAF) and Polybromo-associated BAF (PBAF) complexes, making them among the most frequently mutated complexes in cancer. Recurrent mutations arise in genes encoding several BAF/PBAF subunits, including ARID1A, ARID2, PBRM1, SMARCA4, and SMARCB1 These subunits share some degree of conservation with subunits from related adenosine triphosphate (ATP)-dependent chromatin remodeling complexes in model organisms, in which a large body of work provides insight into their roles in cancer. Here, we review the roles of BAF- and PBAF-like complexes in these organisms, and relate these findings to recent discoveries in cancer epigenomics. We review several roles of BAF and PBAF complexes in cancer, including transcriptional regulation, DNA repair, and regulation of chromatin architecture and topology. More recent results highlight the need for new techniques to study these complexes.
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Affiliation(s)
- Courtney Hodges
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Jacob G Kirkland
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Gerald R Crabtree
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
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19
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Larson A, Fair BJ, Pleiss JA. Interconnections Between RNA-Processing Pathways Revealed by a Sequencing-Based Genetic Screen for Pre-mRNA Splicing Mutants in Fission Yeast. G3 (Bethesda) 2016; 6:1513-23. [PMID: 27172183 DOI: 10.1534/g3.116.027508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Pre-mRNA splicing is an essential component of eukaryotic gene expression and is highly conserved from unicellular yeasts to humans. Here, we present the development and implementation of a sequencing-based reverse genetic screen designed to identify nonessential genes that impact pre-mRNA splicing in the fission yeast Schizosaccharomyces pombe, an organism that shares many of the complex features of splicing in higher eukaryotes. Using a custom-designed barcoding scheme, we simultaneously queried ∼3000 mutant strains for their impact on the splicing efficiency of two endogenous pre-mRNAs. A total of 61 nonessential genes were identified whose deletions resulted in defects in pre-mRNA splicing; enriched among these were factors encoding known or predicted components of the spliceosome. Included among the candidates identified here are genes with well-characterized roles in other RNA-processing pathways, including heterochromatic silencing and 3ʹ end processing. Splicing-sensitive microarrays confirm broad splicing defects for many of these factors, revealing novel functional connections between these pathways.
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20
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Saldi T, Cortazar MA, Sheridan RM, Bentley DL. Coupling of RNA Polymerase II Transcription Elongation with Pre-mRNA Splicing. J Mol Biol 2016; 428:2623-2635. [PMID: 27107644 DOI: 10.1016/j.jmb.2016.04.017] [Citation(s) in RCA: 175] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/27/2016] [Accepted: 04/12/2016] [Indexed: 01/07/2023]
Abstract
Pre-mRNA maturation frequently occurs at the same time and place as transcription by RNA polymerase II. The co-transcriptionality of mRNA processing has permitted the evolution of mechanisms that functionally couple transcription elongation with diverse events that occur on the nascent RNA. This review summarizes the current understanding of the relationship between transcriptional elongation through a chromatin template and co-transcriptional splicing including alternative splicing decisions that affect the expression of most human genes.
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Affiliation(s)
- Tassa Saldi
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, P.O. Box 6511, Aurora, CO 80045, USA
| | - Michael A Cortazar
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, P.O. Box 6511, Aurora, CO 80045, USA
| | - Ryan M Sheridan
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, P.O. Box 6511, Aurora, CO 80045, USA
| | - David L Bentley
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, P.O. Box 6511, Aurora, CO 80045, USA.
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21
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Marina RJ, Sturgill D, Bailly MA, Thenoz M, Varma G, Prigge MF, Nanan KK, Shukla S, Haque N, Oberdoerffer S. TET-catalyzed oxidation of intragenic 5-methylcytosine regulates CTCF-dependent alternative splicing. EMBO J 2015; 35:335-55. [PMID: 26711177 DOI: 10.15252/embj.201593235] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/25/2015] [Indexed: 01/09/2023] Open
Abstract
Intragenic 5-methylcytosine and CTCF mediate opposing effects on pre-mRNA splicing: CTCF promotes inclusion of weak upstream exons through RNA polymerase II pausing, whereas 5-methylcytosine evicts CTCF, leading to exon exclusion. However, the mechanisms governing dynamic DNA methylation at CTCF-binding sites were unclear. Here, we reveal the methylcytosine dioxygenases TET1 and TET2 as active regulators of CTCF-mediated alternative splicing through conversion of 5-methylcytosine to its oxidation derivatives. 5-hydroxymethylcytosine and 5-carboxylcytosine are enriched at an intragenic CTCF-binding sites in the CD45 model gene and are associated with alternative exon inclusion. Reduced TET levels culminate in increased 5-methylcytosine, resulting in CTCF eviction and exon exclusion. In vitro analyses establish the oxidation derivatives are not sufficient to stimulate splicing, but efficiently promote CTCF association. We further show genomewide that reciprocal exchange of 5-hydroxymethylcytosine and 5-methylcytosine at downstream CTCF-binding sites is a general feature of alternative splicing in naïve and activated CD4(+) T cells. These findings significantly expand our current concept of the pre-mRNA "splicing code" to include dynamic intragenic DNA methylation catalyzed by the TET proteins.
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Affiliation(s)
- Ryan J Marina
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - David Sturgill
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Marc A Bailly
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Morgan Thenoz
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Garima Varma
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Maria F Prigge
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Kyster K Nanan
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Sanjeev Shukla
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Nazmul Haque
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
| | - Shalini Oberdoerffer
- Center for Cancer Research, Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD, USA
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