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Choquet K, Chaumont LP, Bache S, Baxter-Koenigs AR, Churchman LS. Genetic regulation of nascent RNA maturation revealed by direct RNA nanopore sequencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.29.610338. [PMID: 39257732 PMCID: PMC11383983 DOI: 10.1101/2024.08.29.610338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2024]
Abstract
Quantitative trait loci analyses have revealed an important role for genetic variants in regulating alternative splicing (AS) and alternative cleavage and polyadenylation (APA) in humans. Yet, these studies are generally performed with mature mRNA, so they report on the outcome rather than the processes of RNA maturation and thus may overlook how variants directly modulate pre-mRNA processing. The order in which the many introns of a human gene are removed can substantially influence AS, while nascent RNA polyadenylation can affect RNA stability and decay. However, how splicing order and poly(A) tail length are regulated by genetic variation has never been explored. Here, we used direct RNA nanopore sequencing to investigate allele-specific pre-mRNA maturation in 12 human lymphoblastoid cell lines. We found frequent splicing order differences between alleles and uncovered significant single nucleotide polymorphism (SNP)-splicing order associations in 17 genes. This included SNPs located in or near splice sites as well as more distal intronic and exonic SNPs. Moreover, several genes showed allele-specific poly(A) tail lengths, many of which also had a skewed allelic abundance ratio. HLA class I transcripts, which encode proteins that play an essential role in antigen presentation, showed the most allele-specific splicing orders, which frequently co-occurred with allele-specific AS, APA or poly(A) tail length differences. Together, our results expose new layers of genetic regulation of pre-mRNA maturation and highlight the power of long-read RNA sequencing for allele-specific analyses.
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Affiliation(s)
- Karine Choquet
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, Canada
- Research Centre on Aging, CIUSSS de l'Estrie-CHUS, Sherbrooke, Canada
| | - Louis-Philippe Chaumont
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, Canada
- Research Centre on Aging, CIUSSS de l'Estrie-CHUS, Sherbrooke, Canada
| | - Simon Bache
- Department of Biochemistry and Functional Genomics, Université de Sherbrooke, Sherbrooke, Canada
- Research Centre on Aging, CIUSSS de l'Estrie-CHUS, Sherbrooke, Canada
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Hérault C, Pihl T, Hudry B. Cellular sex throughout the organism underlies somatic sexual differentiation. Nat Commun 2024; 15:6925. [PMID: 39138201 PMCID: PMC11322332 DOI: 10.1038/s41467-024-51228-6] [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: 11/09/2023] [Accepted: 08/01/2024] [Indexed: 08/15/2024] Open
Abstract
Sex chromosomes underlie the development of male or female sex organs across species. While systemic signals derived from sex organs prominently contribute to sex-linked differences, it is unclear whether the intrinsic presence of sex chromosomes in somatic tissues has a specific function. Here, we use genetic tools to show that cellular sex is crucial for sexual differentiation throughout the body in Drosophila melanogaster. We reveal that every somatic cell converts the intrinsic presence of sex chromosomes into the active production of a sex determinant, a female specific serine- and arginine-rich (SR) splicing factor. This discovery dismisses the mosaic model which posits that only a subset of cells has the potential to sexually differentiate. Using cell-specific sex reversals, we show that this prevalence of cellular sex drives sex differences in organ size and body weight and is essential for fecundity. These findings demonstrate that cellular sex drives differentiation programs at an organismal scale and highlight the importance of cellular sex pathways in sex trait evolution.
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Affiliation(s)
- Chloé Hérault
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, Nice, France
| | - Thomas Pihl
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, Nice, France
| | - Bruno Hudry
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, Nice, France.
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3
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O’Brien MJ, Schrader JM, Ansari A. TFIIB-Termination Factor Interaction Affects Termination of Transcription on Genome-Wide Scale. Int J Mol Sci 2024; 25:8643. [PMID: 39201330 PMCID: PMC11354755 DOI: 10.3390/ijms25168643] [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: 07/05/2024] [Revised: 08/02/2024] [Accepted: 08/06/2024] [Indexed: 09/02/2024] Open
Abstract
Apart from its well-established role in the initiation of transcription, the general transcription factor TFIIB has been implicated in the termination step as well. The ubiquity of TFIIB involvement in termination as well as mechanistic details of its termination function, however, remain largely unexplored. Using GRO-seq analyses, we compared the terminator readthrough phenotype in the sua7-1 mutant (TFIIBsua7-1) and the isogenic wild type (TFIIBWT) strains. Approximately 74% of genes analyzed exhibited a 2-3-fold increase in readthrough of the poly(A)-termination signal in the TFIIBsua7-1 mutant compared to TFIIBWT cells. To understand the mechanistic basis of TFIIB's role in termination, we performed the mass spectrometry of TFIIB-affinity purified from chromatin and soluble cellular fractions-from TFIIBsua7-1 and TFIIBWT cells. TFIIB purified from the chromatin fraction of TFIIBWT cells exhibited significant enrichment of CF1A and Rat1 termination complexes. There was, however, a drastic decrease in TFIIB interaction with CF1A and Rat1 complexes in the TFIIBsua7-1 mutant. ChIP assays revealed about a 90% decline in the recruitment of termination factors in the TFIIBsua7-1 mutant compared to wild type cells. The overall conclusion of these results is that TFIIB affects the termination of transcription on a genome-wide scale, and the TFIIB-termination factor interaction plays a crucial role in the process.
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Affiliation(s)
| | | | - Athar Ansari
- Department of Biological Science, 5047 Gullen Mall, Wayne State University, Detroit, MI 48202, USA; (M.J.O.); (J.M.S.)
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Ozbulut HC, Hilgers V. Neuronal RNA processing: cross-talk between transcriptional regulation and RNA-binding proteins. Front Mol Neurosci 2024; 17:1426410. [PMID: 39149613 PMCID: PMC11324583 DOI: 10.3389/fnmol.2024.1426410] [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: 05/01/2024] [Accepted: 07/22/2024] [Indexed: 08/17/2024] Open
Abstract
In the nervous system, alternative RNA processing is particularly prevalent, which results in the expression of thousands of transcript variants found in no other tissue. Neuron-specific RNA-binding proteins co-transcriptionally regulate alternative splicing, alternative polyadenylation, and RNA editing, thereby shaping the RNA identity of nervous system cells. Recent evidence suggests that interactions between RNA-binding proteins and cis-regulatory elements such as promoters and enhancers play a role in the determination of neuron-specific expression profiles. Here, we discuss possible mechanisms through which transcription and RNA processing cross-talk to generate the uniquely complex neuronal transcriptome, with a focus on alternative 3'-end formation.
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Affiliation(s)
- Hasan Can Ozbulut
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg, Germany
- Faculty of Biology, Albert Ludwig University, Freiburg, Germany
- International Max Planck Research School for Immunobiology, Epigenetics, and Metabolism (IMPRS-IEM), Freiburg, Germany
| | - Valérie Hilgers
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg, Germany
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Fernandes M, Mario de Andrade E, Reis da Silva SG, Romagnoli VDS, Ortega JM, Antônio de Oliveira Mendes T. Geneapp: A web application for visualizing alternative splicing for biomedicine. Comput Biol Med 2024; 178:108789. [PMID: 38936077 DOI: 10.1016/j.compbiomed.2024.108789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 06/29/2024]
Abstract
Alternative Splicing (AS) is an essential mechanism for eukaryotes. However, the consequences of deleting a single exon can be dramatic for the organism and can lead to cancer in humans. Additionally, alternative 5' and 3' splice sites, which define the boundaries of exons, also play key roles to human disorders. Therefore, Investigating AS events is crucial for understanding the molecular basis of human diseases and developing therapeutic strategies. Workflow for AS event analysis can be sampling followed by data analysis with bioinformatics to identify the different AS events in the control and case samples, data visualization for curation, and selection of relevant targets for experimental validation. The raw output of the analysis software does not favor the inspection of events by bioinformaticians requiring custom scripts for data visualization. In this work, we propose the Geneapp application with three modules: GeneappScript, GeneappServer, and GeneappExplorer. GeneappScript is a wrapper that assists in identifying AS in samples compared in two different approaches, while GeneappServer integrates data from AS analysis already performed by the user. In GeneappExplorer, the user visualizes the previous dataset by exploring AS events in genes with functional annotation. This targeted screens that Geneapp allows to perform helps in the identification of targets for experimental validation to confirm the hypotheses under study. The Geneapp is freely available for non-commercial use at https://geneapp.net to advance research on AS for bioinformatics.
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Affiliation(s)
- Miquéias Fernandes
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil.
| | - Edson Mario de Andrade
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil
| | - Saymon Gazolla Reis da Silva
- Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil
| | - Vinícius Dos Santos Romagnoli
- Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil
| | - José Miguel Ortega
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Tiago Antônio de Oliveira Mendes
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil.
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6
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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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7
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Ge B, Dong K, Li R, Bi X, Liu Q, Zhang W, Chen Y, Lu C. Isolation and functional characterization of cold-induced gene (AmCIP) promoter from Ammopiptanthus mongolicus. Gene 2024; 909:148311. [PMID: 38401831 DOI: 10.1016/j.gene.2024.148311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 02/08/2024] [Accepted: 02/21/2024] [Indexed: 02/26/2024]
Abstract
AmCIP is a dehydrin-like protein which involved in abiotic stress tolerance in xerophytes evergreen woody plant A. mongolicus. AmCIP could be induced in the cotyledon and radicle during cold acclimation. To further elucidate the regulation of the upstream region of the gene, we isolated and characterized the promoter of AmCIP. Herein, a 1115 bp 5'-flanking region of AmCIP genomic DNA was isolated and cloned by genome walking from A. mongolicus and the segment sequence was identified as "PrAmCIP" promoter. Analysis of the promoter sequence revealed the presences of some basic cis-acting elements, which were related to various environmental stresses and plant hormones. GUS histochemical staining of transgene tobacco showed that PrAmCIP was induced by 4℃, 55℃, NaCl, mannitol and ABA, whereas it could hardly drive GUS gene expression under normal conditions. Furthermore, we constructed three deletion fragments and genetically transformed them into Arabidopsis thaliana. GUS histochemical staining showed that the MYCATERD1 element of the CP7 fragment (-189 ∼ -1) may be a key element in response to drought. In conclusion, we provide an inducible promoter, PrAmCIP, which can be applied to the development of transgenic plants for abiotic stresse tolerance.
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Affiliation(s)
- Bohao Ge
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Kuo Dong
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Rongchen Li
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Xiaorui Bi
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Qianru Liu
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Weiwei Zhang
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Yuzhen Chen
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
| | - Cunfu Lu
- State Key Laboratory of Efficient Production of Forest Resources, National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
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8
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Xi S, Nguyen T, Murray S, Lorenz P, Mellor J. Size fractionated NET-Seq reveals a conserved architecture of transcription units around yeast genes. Yeast 2024; 41:222-241. [PMID: 38433440 DOI: 10.1002/yea.3931] [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: 10/30/2023] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 03/05/2024] Open
Abstract
Genomes from yeast to humans are subject to pervasive transcription. A single round of pervasive transcription is sufficient to alter local chromatin conformation, nucleosome dynamics and gene expression, but is hard to distinguish from background signals. Size fractionated native elongating transcript sequencing (sfNET-Seq) was developed to precisely map nascent transcripts independent of expression levels. RNAPII-associated nascent transcripts are fractionation into different size ranges before library construction. When anchored to the transcription start sites (TSS) of annotated genes, the combined pattern of the output metagenes gives the expected reference pattern. Bioinformatic pattern matching to the reference pattern identified 9542 transcription units in Saccharomyces cerevisiae, of which 47% are coding and 53% are noncoding. In total, 3113 (33%) are unannotated noncoding transcription units. Anchoring all transcription units to the TSS or polyadenylation site (PAS) of annotated genes reveals distinctive architectures of linked pairs of divergent transcripts approximately 200nt apart. The Reb1 transcription factor is enriched 30nt downstream of the PAS only when an upstream (TSS -60nt with respect to PAS) noncoding transcription unit co-occurs with a downstream (TSS +150nt) coding transcription unit and acts to limit levels of upstream antisense transcripts. The potential for extensive transcriptional interference is evident from low abundance unannotated transcription units with variable TSS (median -240nt) initiating within a 500nt window upstream of, and transcribing over, the promoters of protein-coding genes. This study confirms a highly interleaved yeast genome with different types of transcription units altering the chromatin landscape in distinctive ways, with the potential to exert extensive regulatory control.
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Affiliation(s)
- Shidong Xi
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Tania Nguyen
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Struan Murray
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Phil Lorenz
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Jane Mellor
- Department of Biochemistry, University of Oxford, Oxford, UK
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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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Niederau PA, Eglé P, Willig S, Parsons J, Hoernstein SNW, Decker EL, Reski R. Multifactorial analysis of terminator performance on heterologous gene expression in Physcomitrella. PLANT CELL REPORTS 2024; 43:43. [PMID: 38246952 PMCID: PMC10800305 DOI: 10.1007/s00299-023-03088-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 11/02/2023] [Indexed: 01/23/2024]
Abstract
KEY MESSAGE Characterization of Physcomitrella 3'UTRs across different promoters yields endogenous single and double terminators for usage in molecular pharming. The production of recombinant proteins for health applications accounts for a large share of the biopharmaceutical market. While many drugs are produced in microbial and mammalian systems, plants gain more attention as expression hosts to produce eukaryotic proteins. In particular, the good manufacturing practice (GMP)-compliant moss Physcomitrella (Physcomitrium patens) has outstanding features, such as excellent genetic amenability, reproducible bioreactor cultivation, and humanized protein glycosylation patterns. In this study, we selected and characterized novel terminators for their effects on heterologous gene expression. The Physcomitrella genome contains 53,346 unique 3'UTRs (untranslated regions) of which 7964 transcripts contain at least one intron. Over 91% of 3'UTRs exhibit more than one polyadenylation site, indicating the prevalence of alternative polyadenylation in Physcomitrella. Out of all 3'UTRs, 14 terminator candidates were selected and characterized via transient Dual-Luciferase assays, yielding a collection of endogenous terminators performing equally high as established heterologous terminators CaMV35S, AtHSP90, and NOS. High performing candidates were selected for testing as double terminators which impact reporter levels, dependent on terminator identity and positioning. Testing of 3'UTRs among the different promoters NOS, CaMV35S, and PpActin5 showed an increase of more than 1000-fold between promoters PpActin5 and NOS, whereas terminators increased reporter levels by less than tenfold, demonstrating the stronger effect promoters play as compared to terminators. Among selected terminator attributes, the number of polyadenylation sites as well as polyadenylation signals were found to influence terminator performance the most. Our results improve the biotechnology platform Physcomitrella and further our understanding of how terminators influence gene expression in plants in general.
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Affiliation(s)
| | - Pauline Eglé
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Sandro Willig
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Juliana Parsons
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Eva L Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany.
- Signalling Research Centre BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.
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11
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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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12
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Alfonso-Gonzalez C, Arrigoni L, Ozbulut HC, Falk S, Bönisch U, Hilgers V. Identification of regulatory links between transcription and RNA processing with long-read sequencing. STAR Protoc 2023; 4:102505. [PMID: 37733595 PMCID: PMC10517278 DOI: 10.1016/j.xpro.2023.102505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/07/2023] [Accepted: 07/21/2023] [Indexed: 09/23/2023] Open
Abstract
We present a detailed protocol for sequencing full-length mRNA isoforms using the Oxford nanopore long-read sequencing technology. We describe steps for poly(A) RNA isolation, library preparation, and cDNA size selection. We then detail procedures for sequencing and processing and a computational framework to identify exon couplings and assign mRNA 5' ends and 3' ends to each other. Our approach enables the identification of links between transcription initiation and co-transcriptional RNA processing events. For complete details on the use and execution of this protocol, please refer to Alfonso-Gonzalez et al.1.
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Affiliation(s)
- Carlos Alfonso-Gonzalez
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; Faculty of Biology, Albert Ludwig University, 79104 Freiburg, Germany; International Max Planck Research School for Molecular and Cellular Biology (IMPRS- MCB), 79108 Freiburg, Germany.
| | - Laura Arrigoni
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Hasan Can Ozbulut
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; Faculty of Biology, Albert Ludwig University, 79104 Freiburg, Germany
| | - Stefanie Falk
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Ulrike Bönisch
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Valérie Hilgers
- Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
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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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14
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Zhu P, Schon M, Questa J, Nodine M, Dean C. Causal role of a promoter polymorphism in natural variation of the Arabidopsis floral repressor gene FLC. Curr Biol 2023; 33:4381-4391.e3. [PMID: 37729909 DOI: 10.1016/j.cub.2023.08.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 07/06/2023] [Accepted: 08/25/2023] [Indexed: 09/22/2023]
Abstract
Noncoding polymorphism frequently associates with phenotypic variation, but causation and mechanism are rarely established. Noncoding single-nucleotide polymorphisms (SNPs) characterize the major haplotypes of the Arabidopsis thaliana floral repressor gene FLOWERING LOCUS C (FLC). This noncoding polymorphism generates a range of FLC expression levels, determining the requirement for and the response to winter cold. The major adaptive determinant of these FLC haplotypes was shown to be the autumnal levels of FLC expression. Here, we investigate how noncoding SNPs influence FLC transcriptional output. We identify an upstream transcription start site (uTSS) cluster at FLC, whose usage is increased by an A variant at the promoter SNP-230. This variant is present in relatively few Arabidopsis accessions, with the majority containing G at this site. We demonstrate a causal role for the A variant at -230 in reduced FLC transcriptional output. The G variant upregulates FLC expression redundantly with the major transcriptional activator FRIGIDA (FRI). We demonstrate an additive interaction of SNP-230 with an intronic SNP+259, which also differentially influences uTSS usage. Combinatorial interactions between noncoding SNPs and transcriptional activators thus generate quantitative variation in FLC transcription that has facilitated the adaptation of Arabidopsis accessions to distinct climates.
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Affiliation(s)
- Pan Zhu
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Schon
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Julia Questa
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Michael Nodine
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6708 PB, the Netherlands; Gregor Mendel Institute, Vienna Biocenter, Vienna 1030, Austria
| | - Caroline Dean
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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15
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Zhou J, Li QQ. Stress responses of plants through transcriptome plasticity by mRNA alternative polyadenylation. MOLECULAR HORTICULTURE 2023; 3:19. [PMID: 37789388 PMCID: PMC10536700 DOI: 10.1186/s43897-023-00066-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/07/2023] [Indexed: 10/05/2023]
Abstract
The sessile nature of plants confines their responsiveness to changing environmental conditions. Gene expression regulation becomes a paramount mechanism for plants to adjust their physiological and morphological behaviors. Alternative polyadenylation (APA) is known for its capacity to augment transcriptome diversity and plasticity, thereby furnishing an additional set of tools for modulating gene expression. APA has also been demonstrated to exhibit intimate associations with plant stress responses. In this study, we review APA dynamic features and consequences in plants subjected to both biotic and abiotic stresses. These stresses include adverse environmental stresses, and pathogenic attacks, such as cadmium toxicity, high salt, hypoxia, oxidative stress, cold, heat shock, along with bacterial, fungal, and viral infections. We analyzed the overarching research framework employed to elucidate plant APA response and the alignment of polyadenylation site transitions with the modulation of gene expression levels within the ambit of each stress condition. We also proposed a general APA model where transacting factors, including poly(A) factors, epigenetic regulators, RNA m6A modification factors, and phase separation proteins, assume pivotal roles in APA related transcriptome plasticity during stress response in plants.
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Affiliation(s)
- Jiawen Zhou
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, China
| | - Qingshun Quinn Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, Fujian, China.
- Biomedical Sciences, College of Dental Medicine, Western University of Health Sciences, Pomona, CA, 91766, USA.
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Zhang Z, Bae B, Cuddleston WH, Miura P. Coordination of alternative splicing and alternative polyadenylation revealed by targeted long read sequencing. Nat Commun 2023; 14:5506. [PMID: 37679364 PMCID: PMC10484994 DOI: 10.1038/s41467-023-41207-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Nervous system development is associated with extensive regulation of alternative splicing (AS) and alternative polyadenylation (APA). AS and APA have been extensively studied in isolation, but little is known about how these processes are coordinated. Here, the coordination of cassette exon (CE) splicing and APA in Drosophila was investigated using a targeted long-read sequencing approach we call Pull-a-Long-Seq (PL-Seq). This cost-effective method uses cDNA pulldown and Nanopore sequencing combined with an analysis pipeline to quantify inclusion of alternative exons in connection with alternative 3' ends. Using PL-Seq, we identified genes that exhibit significant differences in CE splicing depending on connectivity to short versus long 3'UTRs. Genomic long 3'UTR deletion was found to alter upstream CE splicing in short 3'UTR isoforms and ELAV loss differentially affected CE splicing depending on connectivity to alternative 3'UTRs. This work highlights the importance of considering connectivity to alternative 3'UTRs when monitoring AS events.
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Affiliation(s)
- Zhiping Zhang
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT, USA
- Department of Biology, University of Nevada, Reno, Reno, NV, USA
| | - Bongmin Bae
- Department of Biology, University of Nevada, Reno, Reno, NV, USA
| | | | - Pedro Miura
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT, USA.
- Department of Biology, University of Nevada, Reno, Reno, NV, USA.
- Institute for System Genomics, University of Connecticut, Storrs, CT, USA.
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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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18
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Gallicchio L, Olivares GH, Berry CW, Fuller MT. Regulation and function of alternative polyadenylation in development and differentiation. RNA Biol 2023; 20:908-925. [PMID: 37906624 PMCID: PMC10730144 DOI: 10.1080/15476286.2023.2275109] [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] [Accepted: 10/17/2023] [Indexed: 11/02/2023] Open
Abstract
Alternative processing of nascent mRNAs is widespread in eukaryotic organisms and greatly impacts the output of gene expression. Specifically, alternative cleavage and polyadenylation (APA) is a co-transcriptional molecular process that switches the polyadenylation site (PAS) at which a nascent mRNA is cleaved, resulting in mRNA isoforms with different 3'UTR length and content. APA can potentially affect mRNA translation efficiency, localization, stability, and mRNA seeded protein-protein interactions. APA naturally occurs during development and cellular differentiation, with around 70% of human genes displaying APA in particular tissues and cell types. For example, neurons tend to express mRNAs with long 3'UTRs due to preferential processing at PASs more distal than other PASs used in other cell types. In addition, changes in APA mark a variety of pathological states, including many types of cancer, in which mRNAs are preferentially cleaved at more proximal PASs, causing expression of mRNA isoforms with short 3'UTRs. Although APA has been widely reported, both the function of APA in development and the mechanisms that regulate the choice of 3'end cut sites in normal and pathogenic conditions are still poorly understood. In this review, we summarize current understanding of how APA is regulated during development and cellular differentiation and how the resulting change in 3'UTR content affects multiple aspects of gene expression. With APA being a widespread phenomenon, the advent of cutting-edge scientific techniques and the pressing need for in-vivo studies, there has never been a better time to delve into the intricate mechanisms of alternative cleavage and polyadenylation.
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Affiliation(s)
- Lorenzo Gallicchio
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, USA
| | - Gonzalo H. Olivares
- Escuela de Kinesiología, Facultad de Medicina y Ciencias de la Salud, Center for Integrative Biology (CIB), Universidad Mayor, Chile and Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | | | - Margaret T. Fuller
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, USA
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