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Capitanchik C, Wilkins OG, Wagner N, Gagneur J, Ule J. From computational models of the splicing code to regulatory mechanisms and therapeutic implications. Nat Rev Genet 2024:10.1038/s41576-024-00774-2. [PMID: 39358547 DOI: 10.1038/s41576-024-00774-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2024] [Indexed: 10/04/2024]
Abstract
Since the discovery of RNA splicing and its role in gene expression, researchers have sought a set of rules, an algorithm or a computational model that could predict the splice isoforms, and their frequencies, produced from any transcribed gene in a specific cellular context. Over the past 30 years, these models have evolved from simple position weight matrices to deep-learning models capable of integrating sequence data across vast genomic distances. Most recently, new model architectures are moving the field closer to context-specific alternative splicing predictions, and advances in sequencing technologies are expanding the type of data that can be used to inform and interpret such models. Together, these developments are driving improved understanding of splicing regulatory mechanisms and emerging applications of the splicing code to the rational design of RNA- and splicing-based therapeutics.
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Affiliation(s)
- Charlotte Capitanchik
- The Francis Crick Institute, London, UK
- UK Dementia Research Institute at King's College London, London, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, UK
| | - Oscar G Wilkins
- The Francis Crick Institute, London, UK
- UCL Queen Square Motor Neuron Disease Centre, Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, UCL, London, UK
| | - Nils Wagner
- School of Computation, Information and Technology, Technical University of Munich, Garching, Germany
- Helmholtz Association - Munich School for Data Science (MUDS), Munich, Germany
| | - Julien Gagneur
- School of Computation, Information and Technology, Technical University of Munich, Garching, Germany.
- Institute of Human Genetics, School of Medicine, Technical University of Munich, Munich, Germany.
- Computational Health Center, Helmholtz Center Munich, Neuherberg, Germany.
| | - Jernej Ule
- The Francis Crick Institute, London, UK.
- UK Dementia Research Institute at King's College London, London, UK.
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, UK.
- National Institute of Chemistry, Ljubljana, Slovenia.
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2
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Ottesen EW, Singh NN, Seo J, Singh RN. U1 snRNA interactions with deep intronic sequences regulate splicing of multiple exons of spinal muscular atrophy genes. Front Neurosci 2024; 18:1412893. [PMID: 39086841 PMCID: PMC11289892 DOI: 10.3389/fnins.2024.1412893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 07/02/2024] [Indexed: 08/02/2024] Open
Abstract
Introduction The U1 small nuclear RNA (snRNA) forms ribonucleoprotein particles (RNPs) such as U1 snRNP and U1-TAF15 snRNP. U1 snRNP is one of the most studied RNPs due to its critical role in pre-mRNA splicing in defining the 5' splice site (5'ss) of every exon through direct interactions with sequences at exon/intron junctions. Recent reports support the role of U1 snRNP in all steps of transcription, namely initiation, elongation, and termination. Functions of U1-TAF15 snRNP are less understood, though it associates with the transcription machinery and may modulate pre-mRNA splicing by interacting with the 5'ss and/or 5'ss-like sequences within the pre-mRNA. An anti-U1 antisense oligonucleotide (ASO) that sequesters the 5' end of U1 snRNA inhibits the functions of U1 snRNP, including transcription and splicing. However, it is not known if the inhibition of U1 snRNP influences post-transcriptional regulation of pre-mRNA splicing through deep intronic sequences. Methods We examined the effect of an anti-U1 ASO that sequesters the 5' end of U1 snRNA on transcription and splicing of all internal exons of the spinal muscular atrophy (SMA) genes, SMN1 and SMN2. Our study was enabled by the employment of a multi-exon-skipping detection assay (MESDA) that discriminates against prematurely terminated transcripts. We employed an SMN2 super minigene to determine if anti-U1 ASO differently affects splicing in the context of truncated introns. Results We observed substantial skipping of multiple internal exons of SMN1 and SMN2 triggered by anti-U1 treatment. Suggesting a role for U1 snRNP in interacting with deep intronic sequences, early exons of the SMN2 super minigene with truncated introns were resistant to anti-U1 induced skipping. Consistently, overexpression of engineered U1 snRNAs targeting the 5'ss of early SMN1 and SMN2 exons did not prevent exon skipping caused by anti-U1 treatment. Discussion Our results uncover a unique role of the U1 snRNA-associated RNPs in splicing regulation executed through deep intronic sequences. Findings are significant for developing novel therapies for SMA based on deep intronic targets.
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Affiliation(s)
| | | | | | - Ravindra N. Singh
- Department of Biomedical Sciences, Iowa State University, Ames, IA, United States
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3
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Love KS, Johnstone CP, Peterman EL, Gaglione S, Galloway KE. Model-guided design of microRNA-based gene circuits supports precise dosage of transgenic cargoes into diverse primary cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.25.600629. [PMID: 38979370 PMCID: PMC11230401 DOI: 10.1101/2024.06.25.600629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
To realize the potential of engineered cells in therapeutic applications, transgenes must be expressed within the window of therapeutic efficacy. Differences in copy number and other sources of extrinsic noise generate variance in transgene expression and limit the performance of synthetic gene circuits. In a therapeutic context, supraphysiological expression of transgenes can compromise engineered phenotypes and lead to toxicity. To ensure a narrow range of transgene expression, we design and characterize Compact microRNA-Mediated Attenuator of Noise and Dosage (ComMAND), a single-transcript, microRNA-based incoherent feedforward loop. We experimentally tune the ComMAND output profile, and we model the system to explore additional tuning strategies. By comparing ComMAND to two-gene implementations, we highlight the precise control afforded by the single-transcript architecture, particularly at relatively low copy numbers. We show that ComMAND tightly regulates transgene expression from lentiviruses and precisely controls expression in primary human T cells, primary rat neurons, primary mouse embryonic fibroblasts, and human induced pluripotent stem cells. Finally, ComMAND effectively sets levels of the clinically relevant transgenes FMRP1 and FXN within a narrow window. Together, ComMAND is a compact tool well-suited to precisely specify expression of therapeutic cargoes.
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Affiliation(s)
- Kasey S. Love
- Department of Biological Engineering, MIT, 25 Ames St., Cambridge, MA 02139, USA
| | | | - Emma L. Peterman
- Department of Chemical Engineering, MIT, 25 Ames St., Cambridge, MA 02139, USA
| | - Stephanie Gaglione
- Department of Chemical Engineering, MIT, 25 Ames St., Cambridge, MA 02139, USA
| | - Kate E. Galloway
- Department of Chemical Engineering, MIT, 25 Ames St., Cambridge, MA 02139, USA
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4
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Shine M, Gordon J, Schärfen L, Zigackova D, Herzel L, Neugebauer KM. Co-transcriptional gene regulation in eukaryotes and prokaryotes. Nat Rev Mol Cell Biol 2024; 25:534-554. [PMID: 38509203 PMCID: PMC11199108 DOI: 10.1038/s41580-024-00706-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2024] [Indexed: 03/22/2024]
Abstract
Many steps of RNA processing occur during transcription by RNA polymerases. Co-transcriptional activities are deemed commonplace in prokaryotes, in which the lack of membrane barriers allows mixing of all gene expression steps, from transcription to translation. In the past decade, an extraordinary level of coordination between transcription and RNA processing has emerged in eukaryotes. In this Review, we discuss recent developments in our understanding of co-transcriptional gene regulation in both eukaryotes and prokaryotes, comparing methodologies and mechanisms, and highlight striking parallels in how RNA polymerases interact with the machineries that act on nascent RNA. The development of RNA sequencing and imaging techniques that detect transient transcription and RNA processing intermediates has facilitated discoveries of transcription coordination with splicing, 3'-end cleavage and dynamic RNA folding and revealed physical contacts between processing machineries and RNA polymerases. Such studies indicate that intron retention in a given nascent transcript can prevent 3'-end cleavage and cause transcriptional readthrough, which is a hallmark of eukaryotic cellular stress responses. We also discuss how coordination between nascent RNA biogenesis and transcription drives fundamental aspects of gene expression in both prokaryotes and eukaryotes.
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Affiliation(s)
- Morgan Shine
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Jackson Gordon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Leonard Schärfen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Dagmar Zigackova
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Lydia Herzel
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Berlin, Germany.
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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5
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Sun L, Hong W, Wang S, Xu Y, Li C. Association of HLA-E single nucleotide polymorphisms with human myeloid leukemia. HLA 2024; 103:e15440. [PMID: 38605657 DOI: 10.1111/tan.15440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 02/12/2024] [Accepted: 02/29/2024] [Indexed: 04/13/2024]
Abstract
Single nucleotide polymorphisms (SNPs) of HLA-E are related to the occurrence of many diseases, but their functions remain unclear. In this study, the function of SNPs at HLA-E rs76971248 and rs1264457 on the myeloid leukemia cells was analyzed by a progressive procedure, included genotyping, mRNA transcription, regulatory element, protein expression, and anti-tumor effect. The frequencies of rs76971248 G and rs1264457 G were found higher in myeloid leukemia patients than those in healthy blood donors (p < 0.05). For myeloid leukemia, rs76971248 T was protective, while rs1264457 G was susceptible. We also found that rs76971248 affected HLA-E mRNA transcription and membrane HLA-E (mHLA-E) expression in K562 cells through differently binding to transcription factor HOXA5 (p < 0.0001), while rs1264457 affected mHLA-E expression by changing mRNA transcription and an encoding amino acid (p < 0.01). In contrast, the expression of soluble HLA-E (sHLA-E) was not influenced by both rs1264457 and rs76971248. The higher HLA-E expression was detected among myeloid leukemia patients, and the K562 cells with higher HLA-E molecules played a significant inhibitory effect on the killing activity of NK-92MI cells (p < 0.05). In conclusion, the higher HLA-E expression of myeloid leukemia cells is promoted by rs76971248 G and rs1264457 G, which helps escape from NK-92MI cells' killing.
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Affiliation(s)
- Liyan Sun
- Department of Transfusion Medicine, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
- Shenzhen Institution of Transfusion Medicine, Shenzhen Blood Center, Shenzhen, China
| | - Wenxu Hong
- Shenzhen Institution of Transfusion Medicine, Shenzhen Blood Center, Shenzhen, China
- Shenzhen Institute of Dermatology, Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen, China
| | - Songxing Wang
- Shenzhen Institution of Transfusion Medicine, Shenzhen Blood Center, Shenzhen, China
| | - Yunping Xu
- Department of Transfusion Medicine, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
- Shenzhen Institution of Transfusion Medicine, Shenzhen Blood Center, Shenzhen, China
| | - Chengyao Li
- Department of Transfusion Medicine, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
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Scott HM, Smith MH, Coleman AK, Armijo KS, Chapman MJ, Apostalo SL, Wagner AR, Watson RO, Patrick KL. Serine/arginine-rich splicing factor 7 promotes the type I interferon response by activating Irf7 transcription. Cell Rep 2024; 43:113816. [PMID: 38393946 PMCID: PMC11056844 DOI: 10.1016/j.celrep.2024.113816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/19/2023] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
Tight regulation of macrophage immune gene expression is required to fight infection without risking harmful inflammation. The contribution of RNA-binding proteins (RBPs) to shaping the macrophage response to pathogens remains poorly understood. Transcriptomic analysis reveals that a member of the serine/arginine-rich (SR) family of mRNA processing factors, SRSF7, is required for optimal expression of a cohort of interferon-stimulated genes in macrophages. Using genetic and biochemical assays, we discover that in addition to its canonical role in regulating alternative splicing, SRSF7 drives transcription of interferon regulatory transcription factor 7 (IRF7) to promote antiviral immunity. At the Irf7 promoter, SRSF7 maximizes STAT1 transcription factor binding and RNA polymerase II elongation via cooperation with the H4K20me1 histone methyltransferase KMT5a (SET8). These studies define a role for an SR protein in activating transcription and reveal an RBP-chromatin network that orchestrates macrophage antiviral gene expression.
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Affiliation(s)
- Haley M Scott
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Mackenzie H Smith
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Aja K Coleman
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Kaitlyn S Armijo
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Morgan J Chapman
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Summer L Apostalo
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Allison R Wagner
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Robert O Watson
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA
| | - Kristin L Patrick
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health, College of Medicine, Bryan, TX 77807, USA.
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Alfonso-Gonzalez C, Hilgers V. (Alternative) transcription start sites as regulators of RNA processing. Trends Cell Biol 2024:S0962-8924(24)00033-3. [PMID: 38531762 DOI: 10.1016/j.tcb.2024.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/28/2024]
Abstract
Alternative transcription start site usage (ATSS) is a widespread regulatory strategy that enables genes to choose between multiple genomic loci for initiating transcription. This mechanism is tightly controlled during development and is often altered in disease states. In this review, we examine the growing evidence highlighting a role for transcription start sites (TSSs) in the regulation of mRNA isoform selection during and after transcription. We discuss how the choice of transcription initiation sites influences RNA processing and the importance of this crosstalk for cell identity and organism function. We also speculate on possible mechanisms underlying the integration of transcriptional and post-transcriptional processes.
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Affiliation(s)
- Carlos Alfonso-Gonzalez
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; Faculty of Biology, Albert Ludwigs University, 79104 Freiburg, Germany; International Max Planck Research School for Molecular and Cellular Biology (IMPRS- MCB), 79108 Freiburg, Germany
| | - Valérie Hilgers
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany.
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8
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Calvo-Roitberg E, Carroll CL, Venev SV, Kim G, Mick ST, Dekker J, Fiszbein A, Pai AA. mRNA initiation and termination are spatially coordinated. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.05.574404. [PMID: 38260419 PMCID: PMC10802295 DOI: 10.1101/2024.01.05.574404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The expression of a precise mRNA transcriptome is crucial for establishing cell identity and function, with dozens of alternative isoforms produced for a single gene sequence. The regulation of mRNA isoform usage occurs by the coordination of co-transcriptional mRNA processing mechanisms across a gene. Decisions involved in mRNA initiation and termination underlie the largest extent of mRNA isoform diversity, but little is known about any relationships between decisions at both ends of mRNA molecules. Here, we systematically profile the joint usage of mRNA transcription start sites (TSSs) and polyadenylation sites (PASs) across tissues and species. Using both short and long read RNA-seq data, we observe that mRNAs preferentially using upstream TSSs also tend to use upstream PASs, and congruently, the usage of downstream sites is similarly paired. This observation suggests that mRNA 5' end choice may directly influence mRNA 3' ends. Our results suggest a novel "Positional Initiation-Termination Axis" (PITA), in which the usage of alternative terminal sites are coupled based on the order in which they appear in the genome. PITA isoforms are more likely to encode alternative protein domains and use conserved sites. PITA is strongly associated with the length of genomic features, such that PITA is enriched in longer genes with more area devoted to regions that regulate alternative 5' or 3' ends. Strikingly, we found that PITA genes are more likely than non-PITA genes to have multiple, overlapping chromatin structural domains related to pairing of ordinally coupled start and end sites. In turn, PITA coupling is also associated with fast RNA Polymerase II (RNAPII) trafficking across these long gene regions. Our findings indicate that a combination of spatial and kinetic mechanisms couple transcription initiation and mRNA 3' end decisions based on ordinal position to define the expression mRNA isoforms.
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Affiliation(s)
| | | | - Sergey V. Venev
- Department of Systems Biology, University Massachusetts Chan Medical School, Worcester, MA
| | - GyeungYun Kim
- Department of Biology, Boston University, Boston, MA
| | | | - Job Dekker
- Department of Systems Biology, University Massachusetts Chan Medical School, Worcester, MA
- Howard Hughes Medical Institute, Chevy Chase, MD
| | - Ana Fiszbein
- Department of Biology, Boston University, Boston, MA
- Center for Computing & Data Sciences, Boston University, Boston, MA
| | - Athma A. Pai
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA
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9
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Lee S, Aubee JI, Lai EC. Regulation of alternative splicing and polyadenylation in neurons. Life Sci Alliance 2023; 6:e202302000. [PMID: 37793776 PMCID: PMC10551640 DOI: 10.26508/lsa.202302000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/06/2023] Open
Abstract
Cell-type-specific gene expression is a fundamental feature of multicellular organisms and is achieved by combinations of regulatory strategies. Although cell-restricted transcription is perhaps the most widely studied mechanism, co-transcriptional and post-transcriptional processes are also central to the spatiotemporal control of gene functions. One general category of expression control involves the generation of multiple transcript isoforms from an individual gene, whose balance and cell specificity are frequently tightly regulated via diverse strategies. The nervous system makes particularly extensive use of cell-specific isoforms, specializing the neural function of genes that are expressed more broadly. Here, we review regulatory strategies and RNA-binding proteins that direct neural-specific isoform processing. These include various classes of alternative splicing and alternative polyadenylation events, both of which broadly diversify the neural transcriptome. Importantly, global alterations of splicing and alternative polyadenylation are characteristic of many neural pathologies, and recent genetic studies demonstrate how misregulation of individual neural isoforms can directly cause mutant phenotypes.
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Affiliation(s)
- Seungjae Lee
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Joseph I Aubee
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
| | - Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA
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10
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Shenasa H, Bentley DL. Pre-mRNA splicing and its cotranscriptional connections. Trends Genet 2023; 39:672-685. [PMID: 37236814 PMCID: PMC10524715 DOI: 10.1016/j.tig.2023.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/23/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023]
Abstract
Transcription of eukaryotic genes by RNA polymerase II (Pol II) yields RNA precursors containing introns that must be spliced out and the flanking exons ligated together. Splicing is catalyzed by a dynamic ribonucleoprotein complex called the spliceosome. Recent evidence has shown that a large fraction of splicing occurs cotranscriptionally as the RNA chain is extruded from Pol II at speeds of up to 5 kb/minute. Splicing is more efficient when it is tethered to the transcription elongation complex, and this linkage permits functional coupling of splicing with transcription. We discuss recent progress that has uncovered a network of connections that link splicing to transcript elongation and other cotranscriptional RNA processing events.
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Affiliation(s)
- Hossein Shenasa
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA
| | - David L Bentley
- Department of Biochemistry and Molecular Genetics, RNA Bioscience Initiative, University of Colorado School of Medicine, PO Box 6511, Aurora, CO 80045, USA.
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11
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Helzer KT, Sharifi MN, Sperger JM, Shi Y, Annala M, Bootsma ML, Reese SR, Taylor A, Kaufmann KR, Krause HK, Schehr JL, Sethakorn N, Kosoff D, Kyriakopoulos C, Burkard ME, Rydzewski NR, Yu M, Harari PM, Bassetti M, Blitzer G, Floberg J, Sjöström M, Quigley DA, Dehm SM, Armstrong AJ, Beltran H, McKay RR, Feng FY, O'Regan R, Wisinski KB, Emamekhoo H, Wyatt AW, Lang JM, Zhao SG. Fragmentomic analysis of circulating tumor DNA-targeted cancer panels. Ann Oncol 2023; 34:813-825. [PMID: 37330052 PMCID: PMC10527168 DOI: 10.1016/j.annonc.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 06/19/2023] Open
Abstract
BACKGROUND The isolation of cell-free DNA (cfDNA) from the bloodstream can be used to detect and analyze somatic alterations in circulating tumor DNA (ctDNA), and multiple cfDNA-targeted sequencing panels are now commercially available for Food and Drug Administration (FDA)-approved biomarker indications to guide treatment. More recently, cfDNA fragmentation patterns have emerged as a tool to infer epigenomic and transcriptomic information. However, most of these analyses used whole-genome sequencing, which is insufficient to identify FDA-approved biomarker indications in a cost-effective manner. PATIENTS AND METHODS We used machine learning models of fragmentation patterns at the first coding exon in standard targeted cancer gene cfDNA sequencing panels to distinguish between cancer and non-cancer patients, as well as the specific tumor type and subtype. We assessed this approach in two independent cohorts: a published cohort from GRAIL (breast, lung, and prostate cancers, non-cancer, n = 198) and an institutional cohort from the University of Wisconsin (UW; breast, lung, prostate, bladder cancers, n = 320). Each cohort was split 70%/30% into training and validation sets. RESULTS In the UW cohort, training cross-validated accuracy was 82.1%, and accuracy in the independent validation cohort was 86.6% despite a median ctDNA fraction of only 0.06. In the GRAIL cohort, to assess how this approach performs in very low ctDNA fractions, training and independent validation were split based on ctDNA fraction. Training cross-validated accuracy was 80.6%, and accuracy in the independent validation cohort was 76.3%. In the validation cohort where the ctDNA fractions were all <0.05 and as low as 0.0003, the cancer versus non-cancer area under the curve was 0.99. CONCLUSIONS To our knowledge, this is the first study to demonstrate that sequencing from targeted cfDNA panels can be utilized to analyze fragmentation patterns to classify cancer types, dramatically expanding the potential capabilities of existing clinically used panels at minimal additional cost.
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Affiliation(s)
- K T Helzer
- Department of Human Oncology, University of Wisconsin, Madison
| | - M N Sharifi
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - J M Sperger
- Department of Medicine, University of Wisconsin, Madison, USA
| | - Y Shi
- Department of Human Oncology, University of Wisconsin, Madison
| | - M Annala
- Department of Urologic Sciences, Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada; Prostate Cancer Research Center, Faculty of Medicine and Health Technology, Tampere University and Tays Cancer Center, Tampere, Finland
| | - M L Bootsma
- Department of Human Oncology, University of Wisconsin, Madison
| | - S R Reese
- Department of Human Oncology, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - A Taylor
- Department of Medicine, University of Wisconsin, Madison, USA
| | - K R Kaufmann
- Department of Medicine, University of Wisconsin, Madison, USA
| | - H K Krause
- Department of Medicine, University of Wisconsin, Madison, USA
| | - J L Schehr
- Carbone Cancer Center, University of Wisconsin, Madison
| | - N Sethakorn
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - D Kosoff
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - C Kyriakopoulos
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - M E Burkard
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - N R Rydzewski
- Department of Human Oncology, University of Wisconsin, Madison
| | - M Yu
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison
| | - P M Harari
- Department of Human Oncology, University of Wisconsin, Madison; Carbone Cancer Center, University of Wisconsin, Madison
| | - M Bassetti
- Department of Human Oncology, University of Wisconsin, Madison; Carbone Cancer Center, University of Wisconsin, Madison
| | - G Blitzer
- Department of Human Oncology, University of Wisconsin, Madison; Carbone Cancer Center, University of Wisconsin, Madison
| | - J Floberg
- Department of Human Oncology, University of Wisconsin, Madison; Carbone Cancer Center, University of Wisconsin, Madison
| | - M Sjöström
- Department of Radiation Oncology, University of California San Francisco, San Francisco; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco
| | - D A Quigley
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco; Departments of Epidemiology and Biostatistics; Urology, University of California San Francisco, San Francisco
| | - S M Dehm
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis
| | - A J Armstrong
- Duke Cancer Institute Center for Prostate and Urologic Cancers, Department of Medicine, Duke University, Durham
| | - H Beltran
- Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston
| | - R R McKay
- Moores Cancer Center, University of California San Diego, La Jolla
| | - F Y Feng
- Department of Radiation Oncology, University of California San Francisco, San Francisco; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis; Division of Hematology and Oncology, Department of Medicine, University of California San Francisco, San Francisco
| | - R O'Regan
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA; Department of Medicine, University of Rochester, Rochester, USA
| | - K B Wisinski
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - H Emamekhoo
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - A W Wyatt
- Department of Urologic Sciences, Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada; Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, Canada
| | - J M Lang
- Carbone Cancer Center, University of Wisconsin, Madison; Department of Medicine, University of Wisconsin, Madison, USA
| | - S G Zhao
- Department of Human Oncology, University of Wisconsin, Madison; Carbone Cancer Center, University of Wisconsin, Madison; William S. Middleton Memorial Veterans' Hospital, Madison, USA.
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12
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Chakraborty A, Mondal S, Mahajan S, Sharma VK. High-quality genome assemblies provide clues on the evolutionary advantage of blue peafowl over green peafowl. Heliyon 2023; 9:e18571. [PMID: 37576271 PMCID: PMC10412995 DOI: 10.1016/j.heliyon.2023.e18571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 07/14/2023] [Accepted: 07/20/2023] [Indexed: 08/15/2023] Open
Abstract
An intriguing example of differential adaptability is the case of two Asian peafowl species, Pavo cristatus (blue peafowl) and Pavo muticus (green peafowl), where the former has a "Least Concern" conservation status and the latter is an "Endangered" species. To understand the genetic basis of this differential adaptability of the two peafowl species, a comparative analysis of these species is much needed to gain the genomic and evolutionary insights. Thus, we constructed a high-quality genome assembly of blue peafowl with an N50 value of 84.81 Mb (pseudochromosome-level assembly), and a high-confidence coding gene set to perform the genomic and evolutionary analyses of blue and green peafowls with 49 other avian species. The analyses revealed adaptive evolution of genes related to neuronal development, immunity, and skeletal muscle development in these peafowl species. Major genes related to axon guidance such as NEO1 and UNC5, semaphorin (SEMA), and ephrin receptor showed adaptive evolution in peafowl species. However, blue peafowl showed the presence of 42% more coding genes compared to the green peafowl along with a higher number of species-specific gene clusters, segmental duplicated genes and expanded gene families, and comparatively higher evolution in neuronal and developmental pathways. Blue peafowl also showed longer branch length compared to green peafowl in the species phylogenetic tree. These genomic insights obtained from the high-quality genome assembly of P. cristatus constructed in this study provide new clues on the superior adaptability of the blue peafowl over green peafowl despite having a recent species divergence time.
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Affiliation(s)
- Abhisek Chakraborty
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, Madhya Pradesh, India
| | - Samuel Mondal
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, Madhya Pradesh, India
| | - Shruti Mahajan
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, Madhya Pradesh, India
| | - Vineet K. Sharma
- MetaBioSys Group, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, Madhya Pradesh, India
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13
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Bergfort A, Neugebauer KM. The promoter as a trip navigator: Guiding alternative polyadenylation site destinations. Mol Cell 2023; 83:2395-2397. [PMID: 37478824 DOI: 10.1016/j.molcel.2023.06.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 07/23/2023]
Abstract
Alfonso-Gonzalez et al.1 present an innovative combination of long-read-sequencing approaches that reveal coupling of alternative transcription start sites and alternative polyadenylation site usage on a global level.
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Affiliation(s)
- Alexandra Bergfort
- 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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14
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Uriostegui-Arcos M, Mick ST, Shi Z, Rahman R, Fiszbein A. Splicing activates transcription from weak promoters upstream of alternative exons. Nat Commun 2023; 14:3435. [PMID: 37301863 PMCID: PMC10256964 DOI: 10.1038/s41467-023-39200-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 06/02/2023] [Indexed: 06/12/2023] Open
Abstract
Transcription and splicing are intrinsically coupled. Alternative splicing of internal exons can fine-tune gene expression through a recently described phenomenon called exon-mediated activation of transcription starts (EMATS). However, the association of this phenomenon with human diseases remains unknown. Here, we develop a strategy to activate gene expression through EMATS and demonstrate its potential for treatment of genetic diseases caused by loss of expression of essential genes. We first identified a catalog of human EMATS genes and provide a list of their pathological variants. To test if EMATS can be used to activate gene expression, we constructed stable cell lines expressing a splicing reporter based on the alternative splicing of motor neuron 2 (SMN2) gene. Using small molecules and antisense oligonucleotides (ASOs) currently used for treatment of spinal muscular atrophy, we demonstrated that increase of inclusion of alternative exons can trigger an activation of gene expression up to 45-fold by enhancing transcription in EMATS-like genes. We observed the strongest effects in genes under the regulation of weak human promoters located proximal to highly included skipped exons.
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Affiliation(s)
| | - Steven T Mick
- Biology Department, Boston University, Boston, 02215, USA
| | - Zhuo Shi
- Biology Department, Massachusetts Institute of Technology, Cambridge, 02139, USA
| | - Rufuto Rahman
- Biology Department, Boston University, Boston, 02215, USA
| | - Ana Fiszbein
- Biology Department, Boston University, Boston, 02215, USA.
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15
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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] [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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16
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Rogalska ME, Vivori C, Valcárcel J. Regulation of pre-mRNA splicing: roles in physiology and disease, and therapeutic prospects. Nat Rev Genet 2023; 24:251-269. [PMID: 36526860 DOI: 10.1038/s41576-022-00556-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2022] [Indexed: 12/23/2022]
Abstract
The removal of introns from mRNA precursors and its regulation by alternative splicing are key for eukaryotic gene expression and cellular function, as evidenced by the numerous pathologies induced or modified by splicing alterations. Major recent advances have been made in understanding the structures and functions of the splicing machinery, in the description and classification of physiological and pathological isoforms and in the development of the first therapies for genetic diseases based on modulation of splicing. Here, we review this progress and discuss important remaining challenges, including predicting splice sites from genomic sequences, understanding the variety of molecular mechanisms and logic of splicing regulation, and harnessing this knowledge for probing gene function and disease aetiology and for the design of novel therapeutic approaches.
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Affiliation(s)
- Malgorzata Ewa Rogalska
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Claudia Vivori
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain
- The Francis Crick Institute, London, UK
| | - Juan Valcárcel
- Genome Biology Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
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17
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Montez M, Majchrowska M, Krzyszton M, Bokota G, Sacharowski S, Wrona M, Yatusevich R, Massana F, Plewczynski D, Swiezewski S. Promoter-pervasive transcription causes RNA polymerase II pausing to boost DOG1 expression in response to salt. EMBO J 2023; 42:e112443. [PMID: 36705062 PMCID: PMC9975946 DOI: 10.15252/embj.2022112443] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/02/2023] [Accepted: 01/09/2023] [Indexed: 01/28/2023] Open
Abstract
Eukaryotic genomes are pervasively transcribed by RNA polymerase II. Yet, the molecular and biological implications of such a phenomenon are still largely puzzling. Here, we describe noncoding RNA transcription upstream of the Arabidopsis thaliana DOG1 gene, which governs salt stress responses and is a key regulator of seed dormancy. We find that expression of the DOG1 gene is induced by salt stress, thereby causing a delay in seed germination. We uncover extensive transcriptional activity on the promoter of the DOG1 gene, which produces a variety of lncRNAs. These lncRNAs, named PUPPIES, are co-directionally transcribed and extend into the DOG1 coding region. We show that PUPPIES RNAs respond to salt stress and boost DOG1 expression, resulting in delayed germination. This positive role of pervasive PUPPIES transcription on DOG1 gene expression is associated with augmented pausing of RNA polymerase II, slower transcription and higher transcriptional burst size. These findings highlight the positive role of upstream co-directional transcription in controlling transcriptional dynamics of downstream genes.
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Affiliation(s)
- Miguel Montez
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Maria Majchrowska
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Michal Krzyszton
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Grzegorz Bokota
- Laboratory of Functional and Structural Genomics, Centre of New TechnologiesUniversity of WarsawWarsawPoland
| | - Sebastian Sacharowski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Magdalena Wrona
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Ruslan Yatusevich
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Ferran Massana
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Dariusz Plewczynski
- Laboratory of Functional and Structural Genomics, Centre of New TechnologiesUniversity of WarsawWarsawPoland
- Laboratory of Bioinformatics and Computational Genomics, Faculty of Mathematics and Information ScienceWarsaw University of TechnologyWarsawPoland
| | - Szymon Swiezewski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
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18
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Boumpas P, Merabet S, Carnesecchi J. Integrating transcription and splicing into cell fate: Transcription factors on the block. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1752. [PMID: 35899407 DOI: 10.1002/wrna.1752] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/22/2022] [Accepted: 07/01/2022] [Indexed: 11/10/2022]
Abstract
Transcription factors (TFs) are present in all life forms and conserved across great evolutionary distances in eukaryotes. From yeast to complex multicellular organisms, they are pivotal players of cell fate decision by orchestrating gene expression at diverse molecular layers. Notably, TFs fine-tune gene expression by coordinating RNA fate at both the expression and splicing levels. They regulate alternative splicing, an essential mechanism for cell plasticity, allowing the production of many mRNA and protein isoforms in precise cell and tissue contexts. Despite this apparent role in splicing, how TFs integrate transcription and splicing to ultimately orchestrate diverse cell functions and cell fate decisions remains puzzling. We depict substantial studies in various model organisms underlining the key role of TFs in alternative splicing for promoting tissue-specific functions and cell fate. Furthermore, we emphasize recent advances describing the molecular link between the transcriptional and splicing activities of TFs. As TFs can bind both DNA and/or RNA to regulate transcription and splicing, we further discuss their flexibility and compatibility for DNA and RNA substrates. Finally, we propose several models integrating transcription and splicing activities of TFs in the coordination and diversification of cell and tissue identities. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Processing > Splicing Mechanisms.
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Affiliation(s)
- Panagiotis Boumpas
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
| | - Samir Merabet
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
| | - Julie Carnesecchi
- Institut de Génomique Fonctionnelle de Lyon, UMR5242, Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique, Université Claude Bernard-Lyon 1, Lyon, France
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19
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Mehta Z, Touma M. Post-Transcriptional Modification by Alternative Splicing and Pathogenic Splicing Variants in Cardiovascular Development and Congenital Heart Defects. Int J Mol Sci 2023; 24:ijms24021555. [PMID: 36675070 PMCID: PMC9862068 DOI: 10.3390/ijms24021555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Advancements in genomics, bioinformatics, and genome editing have uncovered new dimensions in gene regulation. Post-transcriptional modifications by the alternative splicing of mRNA transcripts are critical regulatory mechanisms of mammalian gene expression. In the heart, there is an expanding interest in elucidating the role of alternative splicing in transcriptome regulation. Substantial efforts were directed toward investigating this process in heart development and failure. However, few studies shed light on alternative splicing products and their dysregulation in congenital heart defects (CHDs). While elegant reports showed the crucial roles of RNA binding proteins (RBPs) in orchestrating splicing transitions during heart development and failure, the impact of RBPs dysregulation or genetic variation on CHDs has not been fully addressed. Herein, we review the current understanding of alternative splicing and RBPs' roles in heart development and CHDs. Wediscuss the impact of perinatal splicing transition and its dysregulation in CHDs. We further summarize the discoveries made of causal splicing variants in key transcription factors that are implicated in CHDs. An improved understanding of the roles of alternative splicing in heart development and CHDs may potentially inform novel preventive and therapeutic advancements for newborn infants with CHDs.
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Affiliation(s)
- Zubin Mehta
- Neonatal/Congenital Heart Laboratory, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Children’s Discovery and Innovation Institute, Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Eli and Edythe Broad Stem Cell Research Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Marlin Touma
- Neonatal/Congenital Heart Laboratory, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Children’s Discovery and Innovation Institute, Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Eli and Edythe Broad Stem Cell Research Center, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Correspondence:
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20
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Weiner AI, Zhao G, Zayas HM, Holcomb NP, Adams-Tzivelekidis S, Wong J, Gentile ME, Reddy D, Wei J, Palashikar G, Quansah KK, Vaughan AE. ΔNp63 drives dysplastic alveolar remodeling and restricts epithelial plasticity upon severe lung injury. Cell Rep 2022; 41:111805. [PMID: 36516758 PMCID: PMC9808897 DOI: 10.1016/j.celrep.2022.111805] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 10/13/2022] [Accepted: 11/18/2022] [Indexed: 12/15/2022] Open
Abstract
The lung exhibits a robust, multifaceted regenerative response to severe injuries such as influenza infection, during which quiescent lung-resident epithelial progenitors participate in two distinct reparative pathways: functionally beneficial regeneration via alveolar type 2 (AT2) cell proliferation and differentiation, and dysplastic tissue remodeling via intrapulmonary airway-resident basal p63+ progenitors. Here we show that the basal cell transcription factor ΔNp63 is required for intrapulmonary basal progenitors to participate in dysplastic alveolar remodeling following injury. We find that ΔNp63 restricts the plasticity of intrapulmonary basal progenitors by maintaining either active or repressive histone modifications at key differentiation gene loci. Following loss of ΔNp63, intrapulmonary basal progenitors are capable of either airway or alveolar differentiation depending on their surrounding environment both in vitro and in vivo. Uncovering these regulatory mechanisms of dysplastic repair and lung basal cell fate choice highlight potential therapeutic targets to promote functional alveolar regeneration following severe lung injuries.
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Affiliation(s)
- Aaron I Weiner
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gan Zhao
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hanna M Zayas
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicolas P Holcomb
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephanie Adams-Tzivelekidis
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joanna Wong
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Maria E Gentile
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dyuthi Reddy
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joey Wei
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gargi Palashikar
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kwaku K Quansah
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrew E Vaughan
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Penn Lung Biology Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.
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21
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Murray A, Mendieta JP, Vollmers C, Schmitz RJ. Simple and accurate transcriptional start site identification using Smar2C2 and examination of conserved promoter features. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 112:583-596. [PMID: 36030508 PMCID: PMC9827901 DOI: 10.1111/tpj.15957] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/12/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
The precise and accurate identification and quantification of transcriptional start sites (TSSs) is key to understanding the control of transcription. The core promoter consists of the TSS and proximal non-coding sequences, which are critical in transcriptional regulation. Therefore, the accurate identification of TSSs is important for understanding the molecular regulation of transcription. Existing protocols for TSS identification are challenging and expensive, leaving high-quality data available for a small subset of organisms. This sparsity of data impairs study of TSS usage across tissues or in an evolutionary context. To address these shortcomings, we developed Smart-Seq2 Rolling Circle to Concatemeric Consensus (Smar2C2), which identifies and quantifies TSSs and transcription termination sites. Smar2C2 incorporates unique molecular identifiers that allowed for the identification of as many as 70 million sites, with no known upper limit. We have also generated TSS data sets from as little as 40 pg of total RNA, which was the smallest input tested. In this study, we used Smar2C2 to identify TSSs in Glycine max (soybean), Oryza sativa (rice), Sorghum bicolor (sorghum), Triticum aestivum (wheat) and Zea mays (maize) across multiple tissues. This wide panel of plant TSSs facilitated the identification of evolutionarily conserved features, such as novel patterns in the dinucleotides that compose the initiator element (Inr), that correlated with promoter expression levels across all species examined. We also discovered sequence variations in known promoter motifs that are positioned reliably close to the TSS, such as differences in the TATA box and in the Inr that may prove significant to our understanding and control of transcription initiation. Smar2C2 allows for the easy study of these critical sequences, providing a tool to facilitate discovery.
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Affiliation(s)
- Andrew Murray
- Department of Plant BiologyUniversity of GeorgiaAthensGA30602USA
| | | | - Chris Vollmers
- Deparment of Biomolecular EngineeringUniversity of California Santa CruzSanta CruzCA95064USA
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22
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Hug N, Aitken S, Longman D, Raab M, Armes H, Mann AR, Rio-Machin A, Fitzgibbon J, Rouault-Pierre K, Cáceres JF. A dual role for the RNA helicase DHX34 in NMD and pre-mRNA splicing and its function in hematopoietic differentiation. RNA (NEW YORK, N.Y.) 2022; 28:1224-1238. [PMID: 35768279 PMCID: PMC9380745 DOI: 10.1261/rna.079277.122] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/22/2022] [Indexed: 05/27/2023]
Abstract
The DExD/H-box RNA helicase DHX34 is a nonsense-mediated decay (NMD) factor that together with core NMD factors coregulates NMD targets in nematodes and in vertebrates. Here, we show that DHX34 is also associated with the human spliceosomal catalytic C complex. Mapping of DHX34 endogenous binding sites using cross-linking immunoprecipitation (CLIP) revealed that DHX34 is preferentially associated with pre-mRNAs and locates at exon-intron boundaries. Accordingly, we observed that DHX34 regulates a large number of alternative splicing (AS) events in mammalian cells in culture, establishing a dual role for DHX34 in both NMD and pre-mRNA splicing. We previously showed that germline DHX34 mutations associated to familial myelodysplasia (MDS)/acute myeloid leukemia (AML) predisposition abrogate its activity in NMD. Interestingly, we observe now that DHX34 regulates the splicing of pre-mRNAs that have been linked to AML/MDS predisposition. This is consistent with silencing experiments in hematopoietic stem/progenitor cells (HSPCs) showing that loss of DHX34 results in differentiation blockade of both erythroid and myeloid lineages, which is a hallmark of AML development. Altogether, these data unveil new cellular functions of DHX34 and suggest that alterations in the levels and/or activity of DHX34 could contribute to human disease.
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Affiliation(s)
- Nele Hug
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Stuart Aitken
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Dasa Longman
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Michaela Raab
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Hannah Armes
- Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Abigail R Mann
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Ana Rio-Machin
- Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Jude Fitzgibbon
- Centre for Genomics and Computational Biology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Kevin Rouault-Pierre
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Javier F Cáceres
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
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23
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Terrone S, Valat J, Fontrodona N, Giraud G, Claude JB, Combe E, Lapendry A, Polvèche H, Ameur LB, Duvermy A, Modolo L, Bernard P, Mortreux F, Auboeuf D, Bourgeois C. RNA helicase-dependent gene looping impacts messenger RNA processing. Nucleic Acids Res 2022; 50:9226-9246. [PMID: 36039747 PMCID: PMC9458439 DOI: 10.1093/nar/gkac717] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 07/25/2022] [Accepted: 08/25/2022] [Indexed: 12/24/2022] Open
Abstract
DDX5 and DDX17 are DEAD-box RNA helicase paralogs which regulate several aspects of gene expression, especially transcription and splicing, through incompletely understood mechanisms. A transcriptome analysis of DDX5/DDX17-depleted human cells confirmed the large impact of these RNA helicases on splicing and revealed a widespread deregulation of 3' end processing. In silico analyses and experiments in cultured cells showed the binding and functional contribution of the genome organizing factor CTCF to chromatin sites at or near a subset of DDX5/DDX17-dependent exons that are characterized by a high GC content and a high density of RNA Polymerase II. We propose the existence of an RNA helicase-dependent relationship between CTCF and the dynamics of transcription across DNA and/or RNA structured regions, that contributes to the processing of internal and terminal exons. Moreover, local DDX5/DDX17-dependent chromatin loops spatially connect RNA helicase-regulated exons with their cognate promoter, and we provide the first direct evidence that de novo gene looping modifies alternative splicing and polyadenylation. Overall our findings uncover the impact of DDX5/DDX17-dependent chromatin folding on pre-messenger RNA processing.
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Affiliation(s)
| | | | - Nicolas Fontrodona
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | | | - Jean-Baptiste Claude
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | | | - Audrey Lapendry
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Hélène Polvèche
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France,CECS/AFM, I-STEM, 28 rue Henri Desbruères, F-91100, Corbeil-Essonnes, France
| | - Lamya Ben Ameur
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Arnaud Duvermy
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Laurent Modolo
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Pascal Bernard
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Franck Mortreux
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Didier Auboeuf
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie, F-69364 Lyon, France
| | - Cyril F Bourgeois
- To whom correspondence should be addressed. Tel: +33 47272 8663; Fax: +33 47272 8674;
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Viakhireva I, Kalinchenko N, Vasilyev E, Chistousova GV, Filatova A, Marakhonov A, Rubtsov PM, Skoblov M, Tiulpakov A. A Founder Mutation in the POMC 5'-UTR Causes Proopiomelanocortin Deficiency Through Splicing-Mediated Decrease of mRNA. J Clin Endocrinol Metab 2022; 107:e3654-e3660. [PMID: 35775692 DOI: 10.1210/clinem/dgac397] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Indexed: 11/19/2022]
Abstract
CONTEXT The syndrome of adrenal insufficiency, obesity, and red hair is a rare autosomal recessive disorder. The majority of disease-causing variants associated with the syndrome are located in the coding region of the POMC gene. OBJECTIVE This work describes 7 unrelated patients who shared a novel homozygous mutation in the 5'-untranslated region (UTR) of the POMC gene and functionally characterize this novel variant. METHODS Whole-exome sequencing (WES) with autozygosity mapping, Sanger sequencing, model expression system studies, and RNA sequencing were used for identification of the disease-causing variant and its subsequent functional characterization. Seven unrelated patients of the Perm Tatar ethnic group presented with hypoglycemia and excessive weight gain, low plasma adrenocorticotropin, and cortisol. Five of 7 children had red hair; 6 of 7 patients also showed signs of bronchial obstruction. RESULTS WES showed shared autozygosity regions overlapping the POMC gene. Sanger sequencing of the POMC 5'-UTR detected a homozygous variant chr2:25391366C > T (hg19) at the splice donor site of intron 1. As demonstrated by the model expression system, the variant led to a significant decrease in the POMC messenger RNA level. Analyses of the patients' haplotypes were suggestive of the founder effect. We estimate that the mutation must have occurred at least 4.27 generations ago (95% CI, 0.86-7.67). CONCLUSION This report presents a new molecular mechanism of POMC deficiency and contributes to the information on phenotypic variability in patients with this disorder.
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Affiliation(s)
- Iuliia Viakhireva
- Department of Endocrine Genetics, Research Centre for Medical Genetics, 115522 Moscow, Russian Federation
| | | | - Evgeny Vasilyev
- Endocrinology Research Centre, Moscow 117036, Russian Federation
| | | | - Alexandra Filatova
- Department of Endocrine Genetics, Research Centre for Medical Genetics, 115522 Moscow, Russian Federation
| | - Andrey Marakhonov
- Department of Endocrine Genetics, Research Centre for Medical Genetics, 115522 Moscow, Russian Federation
| | - Petr M Rubtsov
- Engelhardt Institute of Molecular Biology of Russian Academy of Sciences, Moscow 119991, Russian Federation
| | - Mikhail Skoblov
- Department of Endocrine Genetics, Research Centre for Medical Genetics, 115522 Moscow, Russian Federation
| | - Anatoly Tiulpakov
- Department of Endocrine Genetics, Research Centre for Medical Genetics, 115522 Moscow, Russian Federation
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25
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Wright CJ, Smith CWJ, Jiggins CD. Alternative splicing as a source of phenotypic diversity. Nat Rev Genet 2022; 23:697-710. [PMID: 35821097 DOI: 10.1038/s41576-022-00514-4] [Citation(s) in RCA: 120] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2022] [Indexed: 12/27/2022]
Abstract
A major goal of evolutionary genetics is to understand the genetic processes that give rise to phenotypic diversity in multicellular organisms. Alternative splicing generates multiple transcripts from a single gene, enriching the diversity of proteins and phenotypic traits. It is well established that alternative splicing contributes to key innovations over long evolutionary timescales, such as brain development in bilaterians. However, recent developments in long-read sequencing and the generation of high-quality genome assemblies for diverse organisms has facilitated comparisons of splicing profiles between closely related species, providing insights into how alternative splicing evolves over shorter timescales. Although most splicing variants are probably non-functional, alternative splicing is nonetheless emerging as a dynamic, evolutionarily labile process that can facilitate adaptation and contribute to species divergence.
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Affiliation(s)
- Charlotte J Wright
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK. .,Department of Zoology, University of Cambridge, Cambridge, UK.
| | | | - Chris D Jiggins
- Department of Zoology, University of Cambridge, Cambridge, UK.
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26
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Hardwick SA, Hu W, Joglekar A, Fan L, Collier PG, Foord C, Balacco J, Lanjewar S, Sampson MM, Koopmans F, Prjibelski AD, Mikheenko A, Belchikov N, Jarroux J, Lucas AB, Palkovits M, Luo W, Milner TA, Ndhlovu LC, Smit AB, Trojanowski JQ, Lee VMY, Fedrigo O, Sloan SA, Tombácz D, Ross ME, Jarvis E, Boldogkői Z, Gan L, Tilgner HU. Single-nuclei isoform RNA sequencing unlocks barcoded exon connectivity in frozen brain tissue. Nat Biotechnol 2022; 40:1082-1092. [PMID: 35256815 PMCID: PMC9287170 DOI: 10.1038/s41587-022-01231-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 01/20/2022] [Indexed: 12/11/2022]
Abstract
Single-nuclei RNA sequencing characterizes cell types at the gene level. However, compared to single-cell approaches, many single-nuclei cDNAs are purely intronic, lack barcodes and hinder the study of isoforms. Here we present single-nuclei isoform RNA sequencing (SnISOr-Seq). Using microfluidics, PCR-based artifact removal, target enrichment and long-read sequencing, SnISOr-Seq increased barcoded, exon-spanning long reads 7.5-fold compared to naive long-read single-nuclei sequencing. We applied SnISOr-Seq to adult human frontal cortex and found that exons associated with autism exhibit coordinated and highly cell-type-specific inclusion. We found two distinct combination patterns: those distinguishing neural cell types, enriched in TSS-exon, exon-polyadenylation-site and non-adjacent exon pairs, and those with multiple configurations within one cell type, enriched in adjacent exon pairs. Finally, we observed that human-specific exons are almost as tightly coordinated as conserved exons, implying that coordination can be rapidly established during evolution. SnISOr-Seq enables cell-type-specific long-read isoform analysis in human brain and in any frozen or hard-to-dissociate sample.
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Affiliation(s)
- Simon A Hardwick
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Wen Hu
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Anoushka Joglekar
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Li Fan
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Paul G Collier
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | - Careen Foord
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | | | - Samantha Lanjewar
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | | | - Frank Koopmans
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - Andrey D Prjibelski
- Center for Algorithmic Biotechnology, Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia
| | - Alla Mikheenko
- Center for Algorithmic Biotechnology, Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia
| | - Natan Belchikov
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
- Physiology, Biophysics & Systems Biology Program, Weill Cornell Medicine, New York, NY, USA
| | - Julien Jarroux
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | | | - Miklós Palkovits
- Human Brain Tissue Bank, Semmelweis University, Budapest, Hungary
| | - Wenjie Luo
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Teresa A Milner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Lishomwa C Ndhlovu
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - John Q Trojanowski
- Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Virginia M Y Lee
- Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | | | - Steven A Sloan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Dóra Tombácz
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - M Elizabeth Ross
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA
| | | | - Zsolt Boldogkői
- Department of Medical Biology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Li Gan
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Hagen U Tilgner
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
- Center for Neurogenetics, Weill Cornell Medicine, New York, NY, USA.
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Screening thousands of transcribed coding and non-coding regions reveals sequence determinants of RNA polymerase II elongation potential. Nat Struct Mol Biol 2022; 29:613-620. [PMID: 35681023 DOI: 10.1038/s41594-022-00785-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 04/28/2022] [Indexed: 01/07/2023]
Abstract
Precise regulation of transcription by RNA polymerase II (RNAPII) is critical for organismal growth and development. However, what determines whether an engaged RNAPII will synthesize a full-length transcript or terminate prematurely is poorly understood. Notably, RNAPII is far more susceptible to termination when transcribing non-coding RNAs than when synthesizing protein-coding mRNAs, but the mechanisms underlying this are unclear. To investigate the impact of transcribed sequence on elongation potential, we developed a method to screen the effects of thousands of INtegrated Sequences on Expression of RNA and Translation using high-throughput sequencing (INSERT-seq). We found that higher AT content in non-coding RNAs, rather than specific sequence motifs, drives RNAPII termination. Further, we demonstrate that 5' splice sites autonomously stimulate processive transcription, even in the absence of polyadenylation signals. Our results reveal a potent role for the transcribed sequence in dictating gene output and demonstrate the power of INSERT-seq toward illuminating these contributions.
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28
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Yuen M, Worgan L, Iwanski J, Pappas CT, Joshi H, Churko JM, Arbuckle S, Kirk EP, Zhu Y, Roscioli T, Gregorio CC, Cooper ST. Neonatal-lethal dilated cardiomyopathy due to a homozygous LMOD2 donor splice-site variant. Eur J Hum Genet 2022; 30:450-457. [PMID: 35082396 PMCID: PMC8989920 DOI: 10.1038/s41431-022-01043-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/23/2021] [Accepted: 01/07/2022] [Indexed: 12/29/2022] Open
Abstract
Dilated cardiomyopathy (DCM) is characterized by cardiac enlargement and impaired ventricular contractility leading to heart failure. A single report identified variants in leiomodin-2 (LMOD2) as a cause of neonatally-lethal DCM. Here, we describe two siblings with DCM who died shortly after birth due to heart failure. Exome sequencing identified a homozygous LMOD2 variant in both siblings, (GRCh38)chr7:g.123656237G > A; NM_207163.2:c.273 + 1G > A, ablating the donor 5' splice-site of intron-1. Pre-mRNA splicing studies and western blot analysis on cDNA derived from proband cardiac tissue, MyoD-transduced proband skin fibroblasts and HEK293 cells transfected with LMOD2 gene constructs established variant-associated absence of canonically spliced LMOD2 mRNA and full-length LMOD2 protein. Immunostaining of proband heart tissue unveiled abnormally short actin-thin filaments. Our data are consistent with LMOD2 c.273 + 1G > A abolishing/reducing LMOD2 transcript expression by: (1) variant-associated perturbation in initiation of transcription due to ablation of the intron-1 donor; and/or (2) degradation of aberrant LMOD2 transcripts (resulting from use of alternative transcription start-sites or cryptic splice-sites) by nonsense-mediated decay. LMOD2 expression is critical for life and the absence of LMOD2 is associated with thin filament shortening and severe cardiac contractile dysfunction. This study describes the first splice-site variant in LMOD2 and confirms the role of LMOD2 variants in DCM.
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Affiliation(s)
- Michaela Yuen
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Westmead, NSW, Australia.
- Discipline of Child and Adolescent Health, Sydney Medical School, University of Sydney, Camperdown, NSW, Australia.
| | - Lisa Worgan
- Department of Medical Genomics, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Jessika Iwanski
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, USA
| | - Christopher T Pappas
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, USA
| | - Himanshu Joshi
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Jared M Churko
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, USA
| | - Susan Arbuckle
- Department of Histopathology, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - Edwin P Kirk
- New South Wales Health Pathology, Randwick Genomics Laboratory, Randwick, NSW, Australia
- School of Women's and Children's Health, University of New South Wales, Randwick, NSW, Australia
- Centre for Clinical Genetics, Sydney Children's Hospital, Randwick, NSW, Australia
| | - Ying Zhu
- New South Wales Health Pathology, Randwick Genomics Laboratory, Randwick, NSW, Australia
| | - Tony Roscioli
- New South Wales Health Pathology, Randwick Genomics Laboratory, Randwick, NSW, Australia
- Centre for Clinical Genetics, Sydney Children's Hospital, Randwick, NSW, Australia
- Neuroscience Research Australia (NeuRA), University of New South Wales, Sydney, NSW, Australia
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, USA
| | - Sandra T Cooper
- Kids Neuroscience Centre, The Children's Hospital at Westmead, Westmead, NSW, Australia
- Discipline of Child and Adolescent Health, Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
- The Children's Medical Research Institute, Westmead, NSW, Australia
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29
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Reprogramming RNA processing: an emerging therapeutic landscape. Trends Pharmacol Sci 2022; 43:437-454. [PMID: 35331569 DOI: 10.1016/j.tips.2022.02.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 12/13/2022]
Abstract
The production of a mature mRNA requires coordination of multiple processing steps, which ultimately control its content, localization, and stability. These steps include some of the largest macromolecular machines in the cell, which were, until recently, considered undruggable due to their biological complexity. Building from an expanded understanding of the underlying mechanisms that drive these processes, a new wave of therapeutics is seeking to target RNA processing. With a focus on impacting gene regulation at the RNA level, such modalities offer potential for sequence-specific resolution in drug design. Here, we review our current understanding of RNA-processing events and their role in gene regulation, with a focus on the therapeutic opportunities that have emerged within this landscape.
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30
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Nicolet BP, Jansen SBG, Heideveld E, Ouwehand WH, van den Akker E, von Lindern M, Wolkers MC. Circular RNAs exhibit limited evidence for translation, or translation regulation of the mRNA counterpart in terminal hematopoiesis. RNA (NEW YORK, N.Y.) 2022; 28:194-209. [PMID: 34732567 PMCID: PMC8906552 DOI: 10.1261/rna.078754.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
Each day, about 1012 erythrocytes and platelets are released into the bloodstream. This substantial output from hematopoietic stem cells is tightly regulated by transcriptional and epigenetic factors. Whether and how circular RNAs (circRNAs) contribute to the differentiation and/or identity of hematopoietic cells is to date not known. We recently reported that erythrocytes and platelets contain the highest levels and numbers of circRNAs among hematopoietic cells. Here, we provide the first detailed analysis of circRNA expression during erythroid and megakaryoid differentiation. CircRNA expression not only significantly increased upon enucleation, but also had limited overlap between progenitor cells and mature cells, suggesting that circRNA expression stems from regulated processes rather than resulting from mere accumulation. To study circRNA function in hematopoiesis, we first compared the expression levels of circRNAs with the translation efficiency of their mRNA counterpart. We found that only one out of 2531 (0.04%) circRNAs associated with mRNA-translation regulation. Furthermore, irrespective of thousands of identified putative open reading frames, deep ribosome-footprinting sequencing, and mass spectrometry analysis provided little evidence for translation of endogenously expressed circRNAs. In conclusion, circRNAs alter their expression profile during terminal hematopoietic differentiation, yet their contribution to regulate cellular processes remains enigmatic.
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Affiliation(s)
- Benoit P Nicolet
- Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, 1066CX Amsterdam, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
| | - Sjoert B G Jansen
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge CB2 0AW, United Kingdom
| | - Esther Heideveld
- Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, 1066CX Amsterdam, The Netherlands
| | - Willem H Ouwehand
- Department of Haematology, University of Cambridge and NHS Blood and Transplant, Cambridge CB2 0AW, United Kingdom
| | - Emile van den Akker
- Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, 1066CX Amsterdam, The Netherlands
| | - Marieke von Lindern
- Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, 1066CX Amsterdam, The Netherlands
| | - Monika C Wolkers
- Department of Hematopoiesis, Sanquin Research and Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, 1066CX Amsterdam, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
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Fiszbein A, McGurk M, Calvo-Roitberg E, Kim G, Burge CB, Pai AA. Widespread occurrence of hybrid internal-terminal exons in human transcriptomes. SCIENCE ADVANCES 2022; 8:eabk1752. [PMID: 35044812 PMCID: PMC8769537 DOI: 10.1126/sciadv.abk1752] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 11/23/2021] [Indexed: 06/12/2023]
Abstract
Messenger RNA isoform differences are predominantly driven by alternative first, internal, and last exons. Despite the importance of classifying exons to understand isoform structure, few tools examine isoform-specific exon usage. We recently observed that alternative transcription start sites often arise near internal exons, often creating “hybrid” first/internal exons. To systematically detect hybrid exons, we built the hybrid-internal-terminal (HIT) pipeline to classify exons depending on their isoform-specific usage. On the basis of splice junction reads in RNA sequencing data and probabilistic modeling, the HIT index identified thousands of previously misclassified hybrid first-internal and internal-last exons. Hybrid exons are enriched in long genes and genes involved in RNA splicing and have longer flanking introns and strong splice sites. Their usage varies considerably across human tissues. By developing the first method to classify exons according to isoform contexts, our findings document the occurrence of hybrid exons, a common quirk of the human transcriptome.
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Affiliation(s)
- Ana Fiszbein
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biology, Boston University, Boston, MA, USA
| | - Michael McGurk
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - GyeungYun Kim
- Department of Biology, Boston University, Boston, MA, USA
| | - Christopher B. Burge
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Athma A. Pai
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA
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32
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Tan JY, Marques AC. The activity of human enhancers is modulated by the splicing of their associated lncRNAs. PLoS Comput Biol 2022; 18:e1009722. [PMID: 35015755 PMCID: PMC8803168 DOI: 10.1371/journal.pcbi.1009722] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 01/31/2022] [Accepted: 12/05/2021] [Indexed: 11/19/2022] Open
Abstract
Pervasive enhancer transcription is at the origin of more than half of all long noncoding RNAs in humans. Transcription of enhancer-associated long noncoding RNAs (elncRNA) contribute to their cognate enhancer activity and gene expression regulation in cis. Recently, splicing of elncRNAs was shown to be associated with elevated enhancer activity. However, whether splicing of elncRNA transcripts is a mere consequence of accessibility at highly active enhancers or if elncRNA splicing directly impacts enhancer function, remains unanswered. We analysed genetically driven changes in elncRNA splicing, in humans, to address this outstanding question. We showed that splicing related motifs within multi-exonic elncRNAs evolved under selective constraints during human evolution, suggesting the processing of these transcripts is unlikely to have resulted from transcription across spurious splice sites. Using a genome-wide and unbiased approach, we used nucleotide variants as independent genetic factors to directly assess the causal relationship that underpin elncRNA splicing and their cognate enhancer activity. We found that the splicing of most elncRNAs is associated with changes in chromatin signatures at cognate enhancers and target mRNA expression. We provide evidence that efficient and conserved processing of enhancer-associated elncRNAs contributes to enhancer activity. Most, if not all, active enhancers are transcribed, giving rise to a plethora of transcripts, including enhancer-associated long noncoding RNAs (elncRNAs). Changes in elncRNA levels impacts cognate enhancer activity. Recently splicing of elncRNA has also been found to associate with enhancer activity. Whether this associations reflects a contribution of elncRNA splicing to increased enhancer activity or else is simply the consequence of increased chromatin accessibility that promotes transcriptional elongation and allows for spurious splicing events remains unknown. We show that natural selection has acted, at the species and population level, to preserve DNA elements required for frequent and efficient elncRNA splicing Importantly, using a genome-wide and unbiased statistical population genomics approach, we demonstrate that elncRNA splicing is associated with cognate enhancer function, contributing to chromatin status and enhancer activity. Our results provides strong evidence that efficient elncRNA splicing contributes to enhancer activity genome-wide.
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Affiliation(s)
- Jennifer Yihong Tan
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- * E-mail: (JYT); (ACM)
| | - Ana Claudia Marques
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- * E-mail: (JYT); (ACM)
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Paz I, Argoetti A, Cohen N, Even N, Mandel-Gutfreund Y. RBPmap: A Tool for Mapping and Predicting the Binding Sites of RNA-Binding Proteins Considering the Motif Environment. Methods Mol Biol 2022; 2404:53-65. [PMID: 34694603 DOI: 10.1007/978-1-0716-1851-6_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
RNA-binding proteins (RBPs) play a key role in post-transcriptional regulation via binding to coding and non-coding RNAs. Recent development in experimental technologies, aimed to identify the targets of RBPs, has significantly broadened our knowledge on protein-RNA interactions. However, for many RBPs in many organisms and cell types, experimental RNA-binding data is not available. In this chapter we describe a computational approach, named RBPmap, available as a web service via http://rbpmap.technion.ac.il/ and as a stand-alone version for download. RBPmap was designed for mapping and predicting the binding sites of any RBP within a nucleic acid sequence, given the availability of an experimentally defined binding motif of the RBP. The algorithm searches for a sub-sequence that significantly matches the RBP motif, considering the clustering propensity of other weak matches within the motif environment. Here, we present different applications of RBPmap for discovering the involvement of RBPs and their targets in a variety of cellular processes, in health and disease states. Finally, we demonstrate the performance of RBPmap in predicting the binding targets of RBPs in large-scale RNA-binding data, reinforcing the strength of the tool in distinguishing cognate binding sites from weak motifs.
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Affiliation(s)
- Inbal Paz
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Amir Argoetti
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Noa Cohen
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
- Department of Computer Sciences, Technion-Israel Institute of Technology, Haifa, Israel
| | - Niv Even
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
- Department of Computer Sciences, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yael Mandel-Gutfreund
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
- Department of Computer Sciences, Technion-Israel Institute of Technology, Haifa, Israel.
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Huminiecki Ł. Virtual Gene Concept and a Corresponding Pragmatic Research Program in Genetical Data Science. ENTROPY (BASEL, SWITZERLAND) 2021; 24:17. [PMID: 35052043 PMCID: PMC8774939 DOI: 10.3390/e24010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/02/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
Mendel proposed an experimentally verifiable paradigm of particle-based heredity that has been influential for over 150 years. The historical arguments have been reflected in the near past as Mendel's concept has been diversified by new types of omics data. As an effect of the accumulation of omics data, a virtual gene concept forms, giving rise to genetical data science. The concept integrates genetical, functional, and molecular features of the Mendelian paradigm. I argue that the virtual gene concept should be deployed pragmatically. Indeed, the concept has already inspired a practical research program related to systems genetics. The program includes questions about functionality of structural and categorical gene variants, about regulation of gene expression, and about roles of epigenetic modifications. The methodology of the program includes bioinformatics, machine learning, and deep learning. Education, funding, careers, standards, benchmarks, and tools to monitor research progress should be provided to support the research program.
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Affiliation(s)
- Łukasz Huminiecki
- Evolutionary, Computational, and Statistical Genetics, Department of Molecula Biology, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Postępu 36A, Jastrzębiec, 05-552 Warsaw, Poland
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Tran TT, Linga VG, Al-Obaide MAI, Bello-Germino D, Hoda M, Adesanya O, Vasylyeva TL. Congenital nephrotic syndrome in a Hispanic Guatemalan newborn associated with a NPHS1 variant: A case report. Biomed Rep 2021; 16:4. [PMID: 34900253 PMCID: PMC8652645 DOI: 10.3892/br.2021.1487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/05/2021] [Indexed: 11/06/2022] Open
Abstract
Congenital nephrotic syndrome (CNS) is an autosomal recessive disorder usually detected in the first 3 months of life when the syndromes effects manifest, including edema and a failure to gain weight. A baby boy was admitted to the Neonatal Intensive Care Unit for prematurity (35 weeks) with unremarkable maternal prenatal laboratory tests. The patient had persistent systemic hypertension, hypoproteinemia, hypoalbuminemia and nephrotic range proteinuria. CNS was diagnosed, and genetic testing showed a homozygous variant, c.3024A>G (AGA>AGG) in exon 22 of the nephrin locus. Bioinformatics analysis suggested the genetic condition was likely a result of malfunctional DNA binding sites of transcription factors FOXL1 and FOXC1.
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Affiliation(s)
- Thu T Tran
- Department of Pediatrics, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
| | - Vijay G Linga
- Department of Pediatrics, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
| | - Mohammed A I Al-Obaide
- Department of Pediatrics, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
| | - Daniella Bello-Germino
- Department of Pediatrics, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
| | - Mehar Hoda
- Department of Pediatrics, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
| | - Olubukunola Adesanya
- Department of Pediatrics, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
| | - Tetyana L Vasylyeva
- Department of Pediatrics, Texas Tech University Health Sciences Center, Amarillo, TX 79106, USA
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36
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Santos-Rodriguez G, Voineagu I, Weatheritt RJ. Evolutionary dynamics of circular RNAs in primates. eLife 2021; 10:e69148. [PMID: 34542404 PMCID: PMC8516421 DOI: 10.7554/elife.69148] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 09/06/2021] [Indexed: 12/13/2022] Open
Abstract
Many primate genes produce circular RNAs (circRNAs). However, the extent of circRNA conservation between closely related species remains unclear. By comparing tissue-specific transcriptomes across over 70 million years of primate evolution, we identify that within 3 million years circRNA expression profiles diverged such that they are more related to species identity than organ type. However, our analysis also revealed a subset of circRNAs with conserved neural expression across tens of millions of years of evolution. By comparing to species-specific circRNAs, we identified that the downstream intron of the conserved circRNAs display a dramatic lengthening during evolution due to the insertion of novel retrotransposons. Our work provides comparative analyses of the mechanisms promoting circRNAs to generate increased transcriptomic complexity in primates.
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Affiliation(s)
- Gabriela Santos-Rodriguez
- EMBL Australia, Garvan Institute of Medical ResearchDarlinghurstAustralia
- St. Vincent Clinical School, University of New South WalesDarlinghurstAustralia
| | - Irina Voineagu
- School of Biotechnology and Biomolecular Sciences, University of New South WalesSydneyAustralia
| | - Robert J Weatheritt
- EMBL Australia, Garvan Institute of Medical ResearchDarlinghurstAustralia
- St. Vincent Clinical School, University of New South WalesDarlinghurstAustralia
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Coding variants in the PCNT and CEP295 genes contribute to breast cancer risk in Chinese women. Pathol Res Pract 2021; 225:153581. [PMID: 34418690 DOI: 10.1016/j.prp.2021.153581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/02/2021] [Accepted: 08/02/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND Centrioles play pivotal roles in the assembly of centrosomes, their dysfunction is associated with multiple inherited diseases or cancers. To date, few studies have focused on the associations between coding single nucleotide polymorphisms (SNPs) in the centriole duplication cycle genes and the risk of breast cancer in Chinese women. METHODS Twenty-one SNPs were selected from the coding regions of 10 critical centriole genes. The associations between the selected SNPs and breast cancer susceptibility were assessed in a case-control study of Chinese women, which included 1032 cases and 1063 controls. Potential biological functions in the influence of protein stability and the profile of expression quantitative trait loci (eQTL) of the identified SNPs were further evaluated using in silico databases. RESULTS Multivariate logistic regression analyses revealed that a missense SNP rs7279204 in PCNT was significantly associated with an increased risk of breast cancer (additive model: adjusted OR=1.19, 95% CI: 1.02-1.38), while a missense SNP rs77922978 in CEP295 was significantly associated with a decreased risk of breast cancer (additive model: adjusted OR=0.74, 95% CI: 0.56-0.97). Stratification analyses suggested that rs7279204 and rs77922978 exhibited different effects among later first live birth, ER-negative and PR-negative women (P<0.05). Moreover, rs77922978 showed significant differences for ER and PR status strata (heterogeneity test P=0.028, P=0.046). In addition, bioinformatic analyses indicated that the two variants may possess potential functions of reducing the protein stability of their host genes. Further eQTL analysis showed that the rs7279204 was not only correlated with the expression of its host gene PCNT, but also correlated with the expression of its nearby genes, implying its potential roles in regulation of some cancer susceptibility genes. CONCLUSIONS The SNPs rs7279204 and rs77922978 within the coding region of the PCNT and CEP295 genes may contribute to the susceptibility of breast cancer in Han Chinese population.
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Robinson EK, Jagannatha P, Covarrubias S, Cattle M, Smaliy V, Safavi R, Shapleigh B, Abu-Shumays R, Jain M, Cloonan SM, Akeson M, Brooks AN, Carpenter S. Inflammation drives alternative first exon usage to regulate immune genes including a novel iron-regulated isoform of Aim2. eLife 2021; 10:69431. [PMID: 34047695 PMCID: PMC8260223 DOI: 10.7554/elife.69431] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 05/21/2021] [Indexed: 12/11/2022] Open
Abstract
Determining the layers of gene regulation within the innate immune response is critical to our understanding of the cellular responses to infection and dysregulation in disease. We identified a conserved mechanism of gene regulation in human and mouse via changes in alternative first exon (AFE) usage following inflammation, resulting in changes to the isoforms produced. Of these AFE events, we identified 95 unannotated transcription start sites in mice using a de novo transcriptome generated by long-read native RNA-sequencing, one of which is in the cytosolic receptor for dsDNA and known inflammatory inducible gene, Aim2. We show that this unannotated AFE isoform of Aim2 is the predominant isoform expressed during inflammation and contains an iron-responsive element in its 5′UTR enabling mRNA translation to be regulated by iron levels. This work highlights the importance of examining alternative isoform changes and translational regulation in the innate immune response and uncovers novel regulatory mechanisms of Aim2.
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Affiliation(s)
- Elektra K Robinson
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, United States
| | - Pratibha Jagannatha
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, United States.,Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, United States
| | - Sergio Covarrubias
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, United States
| | - Matthew Cattle
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, United States
| | - Valeriya Smaliy
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, United States
| | - Rojin Safavi
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, United States
| | - Barbara Shapleigh
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, United States
| | - Robin Abu-Shumays
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, United States
| | - Miten Jain
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, United States
| | - Suzanne M Cloonan
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medicine, New York, United States
| | - Mark Akeson
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, United States
| | - Angela N Brooks
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, United States
| | - Susan Carpenter
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, United States
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Dwyer K, Agarwal N, Pile L, Ansari A. Gene Architecture Facilitates Intron-Mediated Enhancement of Transcription. Front Mol Biosci 2021; 8:669004. [PMID: 33968994 PMCID: PMC8097089 DOI: 10.3389/fmolb.2021.669004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/31/2021] [Indexed: 12/28/2022] Open
Abstract
Introns impact several vital aspects of eukaryotic organisms like proteomic plasticity, genomic stability, stress response and gene expression. A role for introns in the regulation of gene expression at the level of transcription has been known for more than thirty years. The molecular basis underlying the phenomenon, however, is still not entirely clear. An important clue came from studies performed in budding yeast that indicate that the presence of an intron within a gene results in formation of a multi-looped gene architecture. When looping is defective, these interactions are abolished, and there is no enhancement of transcription despite normal splicing. In this review, we highlight several potential mechanisms through which looping interactions may enhance transcription. The promoter-5′ splice site interaction can facilitate initiation of transcription, the terminator-3′ splice site interaction can enable efficient termination of transcription, while the promoter-terminator interaction can enhance promoter directionality and expedite reinitiation of transcription. Like yeast, mammalian genes also exhibit an intragenic interaction of the promoter with the gene body, especially exons. Such promoter-exon interactions may be responsible for splicing-dependent transcriptional regulation. Thus, the splicing-facilitated changes in gene architecture may play a critical role in regulation of transcription in yeast as well as in higher eukaryotes.
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Affiliation(s)
- Katherine Dwyer
- Department of Biological Science, Wayne State University, Detroit, MI, United States
| | - Neha Agarwal
- Department of Biological Science, Wayne State University, Detroit, MI, United States
| | - Lori Pile
- Department of Biological Science, Wayne State University, Detroit, MI, United States
| | - Athar Ansari
- Department of Biological Science, Wayne State University, Detroit, MI, United States
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40
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Rambout X, Maquat LE. The nuclear cap-binding complex as choreographer of gene transcription and pre-mRNA processing. Genes Dev 2021; 34:1113-1127. [PMID: 32873578 PMCID: PMC7462061 DOI: 10.1101/gad.339986.120] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this review, Rambout and Maquat discuss known roles of the nuclear cap-binding complex (CBC) during the transcription of genes that encode proteins, stitching together past studies from diverse groups to describe the continuum of CBC-mediated checks and balances in eukaryotic cells. The largely nuclear cap-binding complex (CBC) binds to the 5′ caps of RNA polymerase II (RNAPII)-synthesized transcripts and serves as a dynamic interaction platform for a myriad of RNA processing factors that regulate gene expression. While influence of the CBC can extend into the cytoplasm, here we review the roles of the CBC in the nucleus, with a focus on protein-coding genes. We discuss differences between CBC function in yeast and mammals, covering the steps of transcription initiation, release of RNAPII from pausing, transcription elongation, cotranscriptional pre-mRNA splicing, transcription termination, and consequences of spurious transcription. We describe parameters known to control the binding of generic or gene-specific cofactors that regulate CBC activities depending on the process(es) targeted, illustrating how the CBC is an ever-changing choreographer of gene expression.
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Affiliation(s)
- Xavier Rambout
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, New York 14642, USA
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, New York 14642, USA
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41
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Zhu G, Guo YA, Ho D, Poon P, Poh ZW, Wong PM, Gan A, Chang MM, Kleftogiannis D, Lau YT, Tay B, Lim WJ, Chua C, Tan TJ, Koo SL, Chong DQ, Yap YS, Tan I, Ng S, Skanderup AJ. Tissue-specific cell-free DNA degradation quantifies circulating tumor DNA burden. Nat Commun 2021; 12:2229. [PMID: 33850132 PMCID: PMC8044092 DOI: 10.1038/s41467-021-22463-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Accepted: 03/11/2021] [Indexed: 02/08/2023] Open
Abstract
Profiling of circulating tumor DNA (ctDNA) may offer a non-invasive approach to monitor disease progression. Here, we develop a quantitative method, exploiting local tissue-specific cell-free DNA (cfDNA) degradation patterns, that accurately estimates ctDNA burden independent of genomic aberrations. Nucleosome-dependent cfDNA degradation at promoters and first exon-intron junctions is strongly associated with differential transcriptional activity in tumors and blood. A quantitative model, based on just 6 regulatory regions, could accurately predict ctDNA levels in colorectal cancer patients. Strikingly, a model restricted to blood-specific regulatory regions could predict ctDNA levels across both colorectal and breast cancer patients. Using compact targeted sequencing (<25 kb) of predictive regions, we demonstrate how the approach could enable quantitative low-cost tracking of ctDNA dynamics and disease progression. Circulating tumour DNA (ctDNA) represents a non-invasive option to monitor cancer progression. Here, the authors perform deep sequencing of plasma cell-free DNA, and find that nucleosome-dependent cfDNA degradation at 6 specific regulatory regions is predictive of ctDNA burden.
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Affiliation(s)
- Guanhua Zhu
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Yu A Guo
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Danliang Ho
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Polly Poon
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Zhong Wee Poh
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Pui Mun Wong
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Anna Gan
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Mei Mei Chang
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | | | - Yi Ting Lau
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore
| | - Brenda Tay
- National Cancer Center Singapore, Singapore, Singapore
| | - Wan Jun Lim
- National Cancer Center Singapore, Singapore, Singapore
| | - Clarinda Chua
- National Cancer Center Singapore, Singapore, Singapore
| | - Tira J Tan
- National Cancer Center Singapore, Singapore, Singapore
| | - Si-Lin Koo
- National Cancer Center Singapore, Singapore, Singapore
| | - Dawn Q Chong
- National Cancer Center Singapore, Singapore, Singapore
| | - Yoon Sim Yap
- National Cancer Center Singapore, Singapore, Singapore
| | - Iain Tan
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore. .,National Cancer Center Singapore, Singapore, Singapore. .,Duke-NUS Medical School, National University of Singapore, Singapore, Singapore.
| | - Sarah Ng
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore.
| | - Anders J Skanderup
- Genome Institute of Singapore (GIS), A*STAR, Singapore, Singapore. .,National Cancer Center Singapore, Singapore, Singapore.
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Hall NAL, Husain SM, Lee H, Tunbridge EM. Long read transcript profiling of ion channel splice isoforms. Methods Enzymol 2021; 654:345-364. [PMID: 34120721 DOI: 10.1016/bs.mie.2021.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Alternative splicing of RNA transcripts allows a single gene to generate multiple products and is a key means of generating functionally diverse voltage-gated ion channels. Splicing can be regulated according to cell type, cell state, and stage of development to produce a bespoke complement of protein isoforms. Characterizing the identities of full-length transcript isoforms is essential in order to fully understand a gene's expression and function. However, the repertoire of transcript isoforms is not well characterized for most genes. Long read nanopore sequencing allows full-length isoforms to be sequenced, therefore identifying full-length transcripts. Using this approach, we recently discovered that the human CACNA1C gene gives rise to a far greater repertoire of splice isoforms than previously appreciated. Here we provide a detailed overview of the technical approach we used to achieve this. The method described in this chapter combines long read nanopore sequencing with PCR targeting to selectively sequence transcripts of a specific gene of interest.
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Affiliation(s)
- Nicola A L Hall
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom; Oxford Health NHS Foundation Trust, Oxford, United Kingdom
| | - Syed M Husain
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom; Oxford Health NHS Foundation Trust, Oxford, United Kingdom
| | - Hami Lee
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom; Oxford Health NHS Foundation Trust, Oxford, United Kingdom
| | - Elizabeth M Tunbridge
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom; Oxford Health NHS Foundation Trust, Oxford, United Kingdom.
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43
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Understanding transcription across scales: From base pairs to chromosomes. Mol Cell 2021; 81:1601-1616. [PMID: 33770487 DOI: 10.1016/j.molcel.2021.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/23/2021] [Accepted: 02/26/2021] [Indexed: 02/07/2023]
Abstract
The influence of genome organization on transcription is central to our understanding of cell type specification. Higher-order genome organization is established through short- and long-range DNA interactions. Coordination of these interactions, from single atoms to entire chromosomes, plays a fundamental role in transcriptional control of gene expression. Loss of this coupling can result in disease. Analysis of transcriptional regulation typically involves disparate experimental approaches, from structural studies that define angstrom-level interactions to cell-biological and genomic approaches that assess mesoscale relationships. Thus, to fully understand the mechanisms that regulate gene expression, it is critical to integrate the findings gained across these distinct size scales. In this review, I illustrate fundamental ways in which cells regulate transcription in the context of genome organization.
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44
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Hanna R, Flamier A, Barabino A, Bernier G. G-quadruplexes originating from evolutionary conserved L1 elements interfere with neuronal gene expression in Alzheimer's disease. Nat Commun 2021; 12:1828. [PMID: 33758195 PMCID: PMC7987966 DOI: 10.1038/s41467-021-22129-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 03/03/2021] [Indexed: 02/06/2023] Open
Abstract
DNA sequences containing consecutive guanines organized in 4-interspaced tandem repeats can form stable single-stranded secondary structures, called G-quadruplexes (G4). Herein, we report that the Polycomb group protein BMI1 is enriched at heterochromatin regions containing putative G4 DNA sequences, and that G4 structures accumulate in cells with reduced BMI1 expression and/or relaxed chromatin, including sporadic Alzheimer's disease (AD) neurons. In AD neurons, G4 structures preferentially accumulate in lamina-associated domains, and this is rescued by re-establishing chromatin compaction. ChIP-seq analyses reveal that G4 peaks correspond to evolutionary conserved Long Interspersed Element-1 (L1) sequences predicted to be transcriptionally active. Hence, G4 structures co-localize with RNAPII, and inhibition of transcription can reverse the G4 phenotype without affecting chromatin's state, thus uncoupling both components. Intragenic G4 structures affecting splicing events are furthermore associated with reduced neuronal gene expression in AD. Active L1 sequences are thus at the origin of most G4 structures observed in human neurons.
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Affiliation(s)
- Roy Hanna
- Stem Cell and Developmental Biology Laboratory, Hôpital Maisonneuve-Rosemont, Montreal, QC, Canada
| | - Anthony Flamier
- Stem Cell and Developmental Biology Laboratory, Hôpital Maisonneuve-Rosemont, Montreal, QC, Canada
- Whitehead Institute of Biomedical Research, Cambridge, MA, USA
| | - Andrea Barabino
- Stem Cell and Developmental Biology Laboratory, Hôpital Maisonneuve-Rosemont, Montreal, QC, Canada
| | - Gilbert Bernier
- Stem Cell and Developmental Biology Laboratory, Hôpital Maisonneuve-Rosemont, Montreal, QC, Canada.
- Department of Neurosciences, University of Montreal, Montreal, QC, Canada.
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45
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Caizzi L, Monteiro-Martins S, Schwalb B, Lysakovskaia K, Schmitzova J, Sawicka A, Chen Y, Lidschreiber M, Cramer P. Efficient RNA polymerase II pause release requires U2 snRNP function. Mol Cell 2021; 81:1920-1934.e9. [PMID: 33689748 DOI: 10.1016/j.molcel.2021.02.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 01/07/2021] [Accepted: 02/10/2021] [Indexed: 12/21/2022]
Abstract
Transcription by RNA polymerase II (Pol II) is coupled to pre-mRNA splicing, but the underlying mechanisms remain poorly understood. Co-transcriptional splicing requires assembly of a functional spliceosome on nascent pre-mRNA, but whether and how this influences Pol II transcription remains unclear. Here we show that inhibition of pre-mRNA branch site recognition by the spliceosome component U2 snRNP leads to a widespread and strong decrease in new RNA synthesis from human genes. Multiomics analysis reveals that inhibition of U2 snRNP function increases the duration of Pol II pausing in the promoter-proximal region, impairs recruitment of the pause release factor P-TEFb, and reduces Pol II elongation velocity at the beginning of genes. Our results indicate that efficient release of paused Pol II into active transcription elongation requires the formation of functional spliceosomes and that eukaryotic mRNA biogenesis relies on positive feedback from the splicing machinery to the transcription machinery.
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Affiliation(s)
- Livia Caizzi
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Sara Monteiro-Martins
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Björn Schwalb
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Kseniia Lysakovskaia
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Jana Schmitzova
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Anna Sawicka
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ying Chen
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Michael Lidschreiber
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
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Spatial integration of transcription and splicing in a dedicated compartment sustains monogenic antigen expression in African trypanosomes. Nat Microbiol 2021; 6:289-300. [PMID: 33432154 PMCID: PMC7610597 DOI: 10.1038/s41564-020-00833-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 11/16/2020] [Indexed: 12/13/2022]
Abstract
Highly selective gene expression is a key requirement for antigenic variation in several pathogens, allowing evasion of host immune responses and maintenance of persistent infections 1. African trypanosomes, parasites that cause lethal diseases in humans and livestock, employ an antigenic variation mechanism that involves monogenic antigen expression from a pool of >2600 antigen-coding genes 2. In other eukaryotes, the expression of individual genes can be enhanced by mechanisms involving the juxtaposition of otherwise distal chromosomal loci in the three-dimensional nuclear space 3–5. However, trypanosomes lack classical enhancer sequences or regulated transcription initiation 6,7. In this context, it has remained unclear how genome architecture contributes to monogenic transcription elongation and transcript processing. Here, we show that the single expressed antigen coding gene displays a specific inter-chromosomal interaction with a major mRNA splicing locus. Chromosome conformation capture (Hi-C) revealed a dynamic reconfiguration of this inter-chromosomal interaction upon activation of another antigen. Super-resolution microscopy showed the interaction to be heritable and splicing dependent. We find a specific association of the two genomic loci with the antigen exclusion complex, whereby VEX1 occupied the splicing locus and VEX2 the antigen coding locus. Following VEX2 depletion, loss of monogenic antigen expression was accompanied by increased interactions between previously silent antigen genes and the splicing locus. Our results reveal a mechanism to ensure monogenic expression, where antigen transcription and mRNA splicing occur in a specific nuclear compartment. These findings suggest a new means of post-transcriptional gene regulation.
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Thompson MG, Dittmar M, Mallory MJ, Bhat P, Ferretti MB, Fontoura BM, Cherry S, Lynch KW. Viral-induced alternative splicing of host genes promotes influenza replication. eLife 2020; 9:55500. [PMID: 33269701 PMCID: PMC7735754 DOI: 10.7554/elife.55500] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 12/02/2020] [Indexed: 12/17/2022] Open
Abstract
Viral infection induces the expression of numerous host genes that impact the outcome of infection. Here, we show that infection of human lung epithelial cells with influenza A virus (IAV) also induces a broad program of alternative splicing of host genes. Although these splicing-regulated genes are not enriched for canonical regulators of viral infection, we find that many of these genes do impact replication of IAV. Moreover, in several cases, specific inhibition of the IAV-induced splicing pattern also attenuates viral infection. We further show that approximately a quarter of the IAV-induced splicing events are regulated by hnRNP K, a host protein required for efficient splicing of the IAV M transcript in nuclear speckles. Finally, we find an increase in hnRNP K in nuclear speckles upon IAV infection, which may alter accessibility of hnRNP K for host transcripts thereby leading to a program of host splicing changes that promote IAV replication.
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Affiliation(s)
- Matthew G Thompson
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Philadelphia, United States.,Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
| | - Mark Dittmar
- Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Michael J Mallory
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
| | - Prasanna Bhat
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, United States
| | - Max B Ferretti
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States.,Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Beatriz Ma Fontoura
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, United States
| | - Sara Cherry
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Philadelphia, United States.,Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States.,Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Kristen W Lynch
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Philadelphia, United States.,Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
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Transcriptome-wide analysis and modelling of prognostic alternative splicing signatures in invasive breast cancer: a prospective clinical study. Sci Rep 2020; 10:16504. [PMID: 33020551 PMCID: PMC7536242 DOI: 10.1038/s41598-020-73700-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 08/28/2020] [Indexed: 02/07/2023] Open
Abstract
Aberrant alternative splicing (AS) has been highly involved in the tumorigenesis and progression of most cancers. The potential role of AS in invasive breast cancer (IBC) remains largely unknown. In this study, RNA sequencing of IBC samples from The Cancer Genome Atlas was acquired. AS events were screened by conducting univariate and multivariate Cox analysis and least absolute shrinkage and selection operator regression. In total, 2146 survival-related AS events were identified from 1551 parental genes, of which 93 were related to prognosis, and a prognostic marker model containing 14 AS events was constructed. We also constructed the regulatory network of splicing factors (SFs) and AS events, and identified DDX39B as the node SF gene, and verified the accuracy of the network through experiments. Next, we performed quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) in triple negative breast cancer patients with different responses to neoadjuvant chemotherapy, and found that the exon-specific expression of EPHX2, C6orf141, and HERC4 was associated with the different status of patients that received neoadjuvant chemotherapy. In conclusion, this study found that DDX39B, EPHX2 (exo7), and HERC4 (exo23) can be used as potential targets for the treatment of breast cancer, which provides a new idea for the treatment of breast cancer.
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Motter MM, Corva PM, Soria LA. Expression of calpastatin isoforms in three skeletal muscles of Angus steers and their association with fiber type composition and proteolytic potential. Meat Sci 2020; 171:108267. [PMID: 32745871 DOI: 10.1016/j.meatsci.2020.108267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/24/2020] [Accepted: 07/24/2020] [Indexed: 10/23/2022]
Abstract
This study aimed to evaluate the expression of calpastatin (CAST) isoforms and their potential associations with fiber type composition (%RA), calpastatin activity (CA) and myofibril fragmentation index (MFI) in three muscles with known differences in tenderness (infraspinatus, triceps brachii and semitendinosus) of Angus steers. Expression of total CAST (CAST-T) and CAST isoforms I, II, III (2-3) and III (2-4) (including or not exon 3) was evaluated by qRT-PCR. CAST expression and CA were significantly higher and MFI was lower in semitendinosus, the muscle with the highest %RA of IIX fibers. Differential expression of isoforms defined the variability in CAST-T among muscles. Semitendinosus had a higher expression of isoforms II and III (2-3), but lower expression of III (2-4) compared to the other two muscles. Relative expression of isoforms II and III that were defined by promoter preference linked to alternative splicing, seem to be the main factors explaining differences in CAST expression and ultimately in MFI among muscles.
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Affiliation(s)
- Mariana M Motter
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Genética, Chorroarín 280 (1427), Buenos Aires, Argentina
| | - Pablo M Corva
- Universidad Nacional de Mar del Plata, Facultad de Ciencias Agrarias, Unidad Integrada Balcarce, Departamento de Producción Animal, CC276 (CP7620) Balcarce, Argentina
| | - Liliana A Soria
- Universidad de Buenos Aires, Facultad de Ciencias Veterinarias, Cátedra de Genética, Chorroarín 280 (1427), Buenos Aires, Argentina.
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50
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Stanković D, Claudius AK, Schertel T, Bresser T, Uhlirova M. A Drosophila model to study retinitis pigmentosa pathology associated with mutations in the core splicing factor Prp8. Dis Model Mech 2020; 13:dmm043174. [PMID: 32424050 PMCID: PMC7328144 DOI: 10.1242/dmm.043174] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 05/04/2020] [Indexed: 12/30/2022] Open
Abstract
Retinitis pigmentosa (RP) represents genetically heterogeneous and clinically variable disease characterized by progressive degeneration of photoreceptors resulting in a gradual loss of vision. The autosomal dominant RP type 13 (RP13) has been linked to the malfunction of PRPF8, an essential component of the spliceosome. Over 20 different RP-associated PRPF8 mutations have been identified in human patients. However, the cellular and molecular consequences of their expression in vivo in specific tissue contexts remain largely unknown. Here, we establish a Drosophila melanogaster model for RP13 by introducing the nine distinct RP mutations into the fly PRPF8 ortholog prp8 and express the mutant proteins in precise spatiotemporal patterns using the Gal4/UAS system. We show that all nine RP-Prp8 mutant proteins negatively impact developmental timing, albeit to a different extent, when expressed in the endocrine cells producing the primary insect moulting hormone. In the developing eye primordium, uncommitted epithelial precursors rather than differentiated photoreceptors appeared sensitive to Prp8 malfunction. Expression of the two most pathogenic variants, Prp8S>F and Prp8H>R, induced apoptosis causing alterations to the adult eye morphology. The affected tissue mounted stress and cytoprotective responses, while genetic programs underlying neuronal function were attenuated. Importantly, the penetrance and expressivity increased under prp8 heterozygosity. In contrast, blocking apoptosis alleviated cell loss but not the redox imbalance. Remarkably, the pathogenicity of the RP-Prp8 mutations in Drosophila correlates with the severity of clinical phenotypes in patients carrying the equivalent mutations, highlighting the suitability of the Drosophila model for in-depth functional studies of the mechanisms underlying RP13 etiology.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Dimitrije Stanković
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
| | - Ann-Katrin Claudius
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
| | - Thomas Schertel
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
| | - Tina Bresser
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
| | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne 50931, Germany
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