1
|
Mondal A, Kolomeisky AB. How Transcription Factors Binding Stimulates Transcriptional Bursting. J Phys Chem Lett 2024; 15:8781-8789. [PMID: 39163638 DOI: 10.1021/acs.jpclett.4c02050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2024]
Abstract
Transcription is a fundamental biological process of transferring genetic information which often occurs in stochastic bursts when periods of intense activity alternate with quiescent phases. Recent experiments identified strong correlations between the association of transcription factors (TFs) to gene promoters on DNA and transcriptional activity. However, the underlying molecular mechanisms of this phenomenon remain not well understood. Here, we present a theoretical framework that allowed us to investigate how binding dynamics of TF influences transcriptional bursting. Our minimal theoretical model incorporates the most relevant physical-chemical features, including TF exchange among multiple binding sites at gene promoters and TF association/dissociation dynamics. Using analytical calculations supported by Monte Carlo computer simulations, it is demonstrated that transcriptional bursting dynamics depends on the strength of TF binding and the number of binding sites. Stronger TF binding affinity prolongs burst duration but reduces variability, while an optimal number of binding sites maximizes transcriptional noise, facilitating cellular adaptation. Our theoretical method explains available experimental observations quantitatively, confirming the model's predictive accuracy. This study provides important insights into molecular mechanisms of gene expression and regulation, offering a new theoretical tool for understanding complex biological processes.
Collapse
Affiliation(s)
- Anupam Mondal
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Anatoly B Kolomeisky
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| |
Collapse
|
2
|
Ramsköld D, Hendriks GJ, Larsson AJM, Mayr JV, Ziegenhain C, Hagemann-Jensen M, Hartmanis L, Sandberg R. Single-cell new RNA sequencing reveals principles of transcription at the resolution of individual bursts. Nat Cell Biol 2024:10.1038/s41556-024-01486-9. [PMID: 39198695 DOI: 10.1038/s41556-024-01486-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Accepted: 07/15/2024] [Indexed: 09/01/2024]
Abstract
Analyses of transcriptional bursting from single-cell RNA-sequencing data have revealed patterns of variation and regulation in the kinetic parameters that could be inferred. Here we profiled newly transcribed (4-thiouridine-labelled) RNA across 10,000 individual primary mouse fibroblasts to more broadly infer bursting kinetics and coordination. We demonstrate that inference from new RNA profiles could separate the kinetic parameters that together specify the burst size, and that the synthesis rate (and not the transcriptional off rate) controls the burst size. Importantly, transcriptome-wide inference of transcriptional on and off rates provided conclusive evidence that RNA polymerase II transcribes genes in bursts. Recent reports identified examples of transcriptional co-bursting, yet no global analyses have been performed. The deep new RNA profiles we generated with allelic resolution demonstrated that co-bursting rarely appears more frequently than expected by chance, except for certain gene pairs, notably paralogues located in close genomic proximity. Altogether, new RNA single-cell profiling critically improves the inference of transcriptional bursting and provides strong evidence for independent transcriptional bursting of mammalian genes.
Collapse
Affiliation(s)
- Daniel Ramsköld
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Gert-Jan Hendriks
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Anton J M Larsson
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Juliane V Mayr
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Christoph Ziegenhain
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | | | - Leonard Hartmanis
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Rickard Sandberg
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden.
| |
Collapse
|
3
|
Chen R, Shi X, Yao X, Gao T, Huang G, Ning D, Cao Z, Xu Y, Liang W, Tian SZ, Zhu Q, Fang L, Zheng M, Hu Y, Cui H, Chen W. Specific multivalent molecules boost CRISPR-mediated transcriptional activation. Nat Commun 2024; 15:7222. [PMID: 39174527 PMCID: PMC11341856 DOI: 10.1038/s41467-024-51694-y] [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: 01/14/2024] [Accepted: 08/15/2024] [Indexed: 08/24/2024] Open
Abstract
CRISPR/Cas-based transcriptional activators can be enhanced by intrinsically disordered regions (IDRs). However, the underlying mechanisms are still debatable. Here, we examine 12 well-known IDRs by fusing them to the dCas9-VP64 activator, of which only seven can augment activation, albeit independently of their phase separation capabilities. Moreover, modular domains (MDs), another class of multivalent molecules, though ineffective in enhancing dCas9-VP64 activity on their own, show substantial enhancement in transcriptional activation when combined with dCas9-VP64-IDR. By varying the number of gRNA binding sites and fusing dCas9-VP64 with different IDRs/MDs, we uncover that optimal, rather than maximal, cis-trans cooperativity enables the most robust activation. Finally, targeting promoter-enhancer pairs yields synergistic effects, which can be further amplified via enhancing chromatin interactions. Overall, our study develops a versatile platform for efficient gene activation and sheds important insights into CRIPSR-based transcriptional activators enhanced with multivalent molecules.
Collapse
Affiliation(s)
- Rui Chen
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Innovative Center for RNA Therapeutics (ICRT), School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, China
| | - Xinyao Shi
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Xiangrui Yao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Tong Gao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Guangyu Huang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Duo Ning
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Zemin Cao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Youxin Xu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Weizheng Liang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Central Laboratory, The First Affiliated Hospital of Hebei North University, Zhangjiakou, Hebei, China
| | - Simon Zhongyuan Tian
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Innovative Center for RNA Therapeutics (ICRT), School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Qionghua Zhu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Innovative Center for RNA Therapeutics (ICRT), School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, China
| | - Liang Fang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Innovative Center for RNA Therapeutics (ICRT), School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, China
| | - Meizhen Zheng
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Innovative Center for RNA Therapeutics (ICRT), School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yuhui Hu
- Department of Pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen, China
- Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Huanhuan Cui
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
- Innovative Center for RNA Therapeutics (ICRT), School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
- Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, China.
| | - Wei Chen
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
- Innovative Center for RNA Therapeutics (ICRT), School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
- Department of Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
- Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, China.
| |
Collapse
|
4
|
Trzaskoma P, Jung S, Pękowska A, Bohrer CH, Wang X, Naz F, Dell’Orso S, Dubois WD, Olivera A, Vartak SV, Zhao Y, Nayak S, Overmiller A, Morasso MI, Sartorelli V, Larson DR, Chow CC, Casellas R, O’Shea JJ. 3D chromatin architecture, BRD4, and Mediator have distinct roles in regulating genome-wide transcriptional bursting and gene network. SCIENCE ADVANCES 2024; 10:eadl4893. [PMID: 39121214 PMCID: PMC11313860 DOI: 10.1126/sciadv.adl4893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 07/08/2024] [Indexed: 08/11/2024]
Abstract
Discontinuous transcription is evolutionarily conserved and a fundamental feature of gene regulation; yet, the exact mechanisms underlying transcriptional bursting are unresolved. Analyses of bursting transcriptome-wide have focused on the role of cis-regulatory elements, but other factors that regulate this process remain elusive. We applied mathematical modeling to single-cell RNA sequencing data to infer bursting dynamics transcriptome-wide under multiple conditions to identify possible molecular mechanisms. We found that Mediator complex subunit 26 (MED26) primarily regulates frequency, MYC regulates burst size, while cohesin and Bromodomain-containing protein 4 (BRD4) can modulate both. Despite comparable effects on RNA levels among these perturbations, acute depletion of MED26 had the most profound impact on the entire gene regulatory network, acting downstream of chromatin spatial architecture and without affecting TATA box-binding protein (TBP) recruitment. These results indicate that later steps in the initiation of transcriptional bursts are primary nodes for integrating gene networks in single cells.
Collapse
Affiliation(s)
- Pawel Trzaskoma
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - SeolKyoung Jung
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Aleksandra Pękowska
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
- Dioscuri Centre for Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | | | - Xiang Wang
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Faiza Naz
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Stefania Dell’Orso
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Wendy D. Dubois
- National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ana Olivera
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Supriya V. Vartak
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Yongbing Zhao
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Subhashree Nayak
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Andrew Overmiller
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Maria I. Morasso
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Vittorio Sartorelli
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Daniel R. Larson
- National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Carson C. Chow
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Rafael Casellas
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - John J. O’Shea
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
5
|
Keikhosravi A, Almansour F, Bohrer CH, Fursova NA, Guin K, Sood V, Misteli T, Larson DR, Pegoraro G. High-throughput image processing software for the study of nuclear architecture and gene expression. Sci Rep 2024; 14:18426. [PMID: 39117696 PMCID: PMC11310328 DOI: 10.1038/s41598-024-66600-1] [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: 10/27/2023] [Accepted: 07/02/2024] [Indexed: 08/10/2024] Open
Abstract
High-throughput imaging (HTI) generates complex imaging datasets from a large number of experimental perturbations. Commercial HTI software programs for image analysis workflows typically do not allow full customization and adoption of new image processing algorithms in the analysis modules. While open-source HTI analysis platforms provide individual modules in the workflow, like nuclei segmentation, spot detection, or cell tracking, they are often limited in integrating novel analysis modules or algorithms. Here, we introduce the High-Throughput Image Processing Software (HiTIPS) to expand the range and customization of existing HTI analysis capabilities. HiTIPS incorporates advanced image processing and machine learning algorithms for automated cell and nuclei segmentation, spot signal detection, nucleus tracking, nucleus registration, spot tracking, and quantification of spot signal intensity. Furthermore, HiTIPS features a graphical user interface that is open to integration of new analysis modules for existing analysis pipelines and to adding new analysis modules. To demonstrate the utility of HiTIPS, we present three examples of image analysis workflows for high-throughput DNA FISH, immunofluorescence (IF), and live-cell imaging of transcription in single cells. Altogether, we demonstrate that HiTIPS is a user-friendly, flexible, and open-source HTI software platform for a variety of cell biology applications.
Collapse
Affiliation(s)
- Adib Keikhosravi
- High-Throughput Imaging Facility, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Faisal Almansour
- Cell Biology of Genomes, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University Medical School, Washington, DC, 20057, USA
| | - Christopher H Bohrer
- System Biology of Gene Expression, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Nadezda A Fursova
- System Biology of Gene Expression, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Krishnendu Guin
- Cell Biology of Genomes, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Varun Sood
- Cell Biology of Genomes, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
- System Biology of Gene Expression, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Tom Misteli
- Cell Biology of Genomes, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Daniel R Larson
- System Biology of Gene Expression, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Gianluca Pegoraro
- High-Throughput Imaging Facility, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA.
| |
Collapse
|
6
|
Whitney PH, Lionnet T. The method in the madness: Transcriptional control from stochastic action at the single-molecule scale. Curr Opin Struct Biol 2024; 87:102873. [PMID: 38954990 PMCID: PMC11373363 DOI: 10.1016/j.sbi.2024.102873] [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: 01/12/2024] [Revised: 05/07/2024] [Accepted: 06/05/2024] [Indexed: 07/04/2024]
Abstract
Cell states result from the ordered activation of gene expression by transcription factors. Transcription factors face opposing design constraints: they need to be dynamic to trigger rapid cell state transitions, but also stable enough to maintain terminal cell identities indefinitely. Recent progress in live-cell single-molecule microscopy has helped define the biophysical principles underlying this paradox. Beyond transcription factor activity, single-molecule experiments have revealed that at nearly every level of transcription regulation, control emerges from multiple short-lived stochastic interactions, rather than deterministic, stable interactions typical of other biochemical pathways. This architecture generates consistent outcomes that can be rapidly choreographed. Here, we highlight recent results that demonstrate how order in transcription regulation emerges from the apparent molecular-scale chaos and discuss remaining conceptual challenges.
Collapse
Affiliation(s)
- Peter H Whitney
- Institute for Systems Genetics, New York University School of Medicine, New York, NY 10016, USA; Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
| | - Timothée Lionnet
- Institute for Systems Genetics, New York University School of Medicine, New York, NY 10016, USA; Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA; Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY 11201, USA.
| |
Collapse
|
7
|
Nemsick S, Hansen AS. Molecular models of bidirectional promoter regulation. Curr Opin Struct Biol 2024; 87:102865. [PMID: 38905929 DOI: 10.1016/j.sbi.2024.102865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/30/2024] [Accepted: 05/27/2024] [Indexed: 06/23/2024]
Abstract
Approximately 11% of human genes are transcribed by a bidirectional promoter (BDP), defined as two genes with <1 kb between their transcription start sites. Despite their evolutionary conservation and enrichment for housekeeping genes and oncogenes, the regulatory role of BDPs remains unclear. BDPs have been suggested to facilitate gene coregulation and/or decrease expression noise. This review discusses these potential regulatory functions through the context of six prospective underlying mechanistic models: a single nucleosome free region, shared transcription factor/regulator binding, cooperative negative supercoiling, bimodal histone marks, joint activation by enhancer(s), and RNA-mediated recruitment of regulators. These molecular mechanisms may act independently and/or cooperatively to facilitate the coregulation and/or decreased expression noise predicted of BDPs.
Collapse
Affiliation(s)
- Sarah Nemsick
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; The Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA
| | - Anders S Hansen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; The Gene Regulation Observatory, Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA.
| |
Collapse
|
8
|
Ietswaart R, Smalec BM, Xu A, Choquet K, McShane E, Jowhar ZM, Guegler CK, Baxter-Koenigs AR, West ER, Fu BXH, Gilbert L, Floor SN, Churchman LS. Genome-wide quantification of RNA flow across subcellular compartments reveals determinants of the mammalian transcript life cycle. Mol Cell 2024; 84:2765-2784.e16. [PMID: 38964322 PMCID: PMC11315470 DOI: 10.1016/j.molcel.2024.06.008] [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: 09/23/2022] [Revised: 05/15/2024] [Accepted: 06/11/2024] [Indexed: 07/06/2024]
Abstract
Dissecting the regulatory mechanisms controlling mammalian transcripts from production to degradation requires quantitative measurements of mRNA flow across the cell. We developed subcellular TimeLapse-seq to measure the rates at which RNAs are released from chromatin, exported from the nucleus, loaded onto polysomes, and degraded within the nucleus and cytoplasm in human and mouse cells. These rates varied substantially, yet transcripts from genes with related functions or targeted by the same transcription factors and RNA-binding proteins flowed across subcellular compartments with similar kinetics. Verifying these associations uncovered a link between DDX3X and nuclear export. For hundreds of RNA metabolism genes, most transcripts with retained introns were degraded by the nuclear exosome, while the remaining molecules were exported with stable cytoplasmic lifespans. Transcripts residing on chromatin for longer had extended poly(A) tails, whereas the reverse was observed for cytoplasmic mRNAs. Finally, machine learning identified molecular features that predicted the diverse life cycles of mRNAs.
Collapse
Affiliation(s)
- Robert Ietswaart
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
| | - Brendan M Smalec
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Albert Xu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Karine Choquet
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Erik McShane
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ziad Mohamoud Jowhar
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Chantal K Guegler
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Autum R Baxter-Koenigs
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Emma R West
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | | | - Luke Gilbert
- Arc Institute, Palo Alto, CA 94305, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Urology, University of California, San Francisco, San Francisco, CA 94518, USA
| | - Stephen N Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
9
|
van Haaren MJH, Steller LB, Vastert SJ, Calis JJA, van Loosdregt J. Get Spliced: Uniting Alternative Splicing and Arthritis. Int J Mol Sci 2024; 25:8123. [PMID: 39125692 PMCID: PMC11311815 DOI: 10.3390/ijms25158123] [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: 06/25/2024] [Revised: 07/21/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024] Open
Abstract
Immune responses demand the rapid and precise regulation of gene protein expression. Splicing is a crucial step in this process; ~95% of protein-coding gene transcripts are spliced during mRNA maturation. Alternative splicing allows for distinct functional regulation, as it can affect transcript degradation and can lead to alternative functional protein isoforms. There is increasing evidence that splicing can directly regulate immune responses. For several genes, immune cells display dramatic changes in isoform-level transcript expression patterns upon activation. Recent advances in long-read RNA sequencing assays have enabled an unbiased and complete description of transcript isoform expression patterns. With an increasing amount of cell types and conditions that have been analyzed with such assays, thousands of novel transcript isoforms have been identified. Alternative splicing has been associated with autoimmune diseases, including arthritis. Here, GWASs revealed that SNPs associated with arthritis are enriched in splice sites. In this review, we will discuss how alternative splicing is involved in immune responses and how the dysregulation of alternative splicing can contribute to arthritis pathogenesis. In addition, we will discuss the therapeutic potential of modulating alternative splicing, which includes examples of spliceform-based biomarkers for disease severity or disease subtype, splicing manipulation using antisense oligonucleotides, and the targeting of specific immune-related spliceforms using antibodies.
Collapse
Affiliation(s)
- Maurice J. H. van Haaren
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Levina Bertina Steller
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Sebastiaan J. Vastert
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
- Division of Pediatric Rheumatology and Immunology, Wilhelmina Children’s Hospital, 3584 CX Utrecht, The Netherlands
| | - Jorg J. A. Calis
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Jorg van Loosdregt
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| |
Collapse
|
10
|
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.
Collapse
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.
| |
Collapse
|
11
|
Almansour F, Keikhosravi A, Pegoraro G, Misteli T. Allele-level visualization of transcription and chromatin by high-throughput imaging. Histochem Cell Biol 2024; 162:65-77. [PMID: 38724854 PMCID: PMC11227451 DOI: 10.1007/s00418-024-02289-7] [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: 04/11/2024] [Indexed: 05/21/2024]
Abstract
The spatial arrangement of the genome within the nucleus is a pivotal aspect of cellular organization and function with implications for gene expression and regulation. While all genome organization features, such as loops, domains, and radial positioning, are nonrandom, they are characterized by a high degree of single-cell variability. Imaging approaches are ideally suited to visualize, measure, and study single-cell heterogeneity in genome organization. Here, we describe two methods for the detection of DNA and RNA of individual gene alleles by fluorescence in situ hybridization (FISH) in a high-throughput format. We have optimized combined DNA/RNA FISH approaches either using simultaneous or sequential detection of DNA and nascent RNA. These optimized DNA and RNA FISH protocols were implemented in a 384-well plate format alongside automated image and data analysis and enable accurate detection of individual gene alleles and their gene expression status across a large cell population. We successfully visualized MYC and EGFR DNA and nascent RNA with allele-level resolution in multiple cell types, and we determined the radial position of active and inactive MYC and EGFR alleles. These optimized DNA/RNA detection approaches are versatile and sensitive tools for mapping of chromatin features and gene activity at the single-allele level and at high throughput.
Collapse
Affiliation(s)
- Faisal Almansour
- Cell Biology of Genomes, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University Medical School, Washington, DC, 20057, USA
| | - Adib Keikhosravi
- High-Throughput Imaging Facility, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Gianluca Pegoraro
- High-Throughput Imaging Facility, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA
| | - Tom Misteli
- Cell Biology of Genomes, National Cancer Institute, National Institute of Health, Bethesda, MD, 20892, USA.
| |
Collapse
|
12
|
Chen PT, Levo M, Zoller B, Gregor T. Gene activity fully predicts transcriptional bursting dynamics. ARXIV 2024:arXiv:2304.08770v3. [PMID: 37131882 PMCID: PMC10153294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Transcription commonly occurs in bursts, with alternating productive (ON) and quiescent (OFF) periods, governing mRNA production rates. Yet, how transcription is regulated through bursting dynamics remains unresolved. Here, we conduct real-time measurements of endogenous transcriptional bursting with single-mRNA sensitivity. Leveraging the diverse transcriptional activities in early fly embryos, we uncover stringent relationships between bursting parameters. Specifically, we find that the durations of ON and OFF periods are linked. Regardless of the developmental stage or body-axis position, gene activity levels predict individual alleles' average ON and OFF periods. Lowly transcribing alleles predominantly modulate OFF periods (burst frequency), while highly transcribing alleles primarily tune ON periods (burst size). These relationships persist even under perturbations of cis-regulatory elements or trans-factors and account for bursting dynamics measured in other species. Our results suggest a novel mechanistic constraint governing bursting dynamics rather than a modular control of distinct parameters by distinct regulatory processes.
Collapse
Affiliation(s)
- Po-Ta Chen
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Michal Levo
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Benjamin Zoller
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Stem Cell and Developmental Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| | - Thomas Gregor
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Stem Cell and Developmental Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| |
Collapse
|
13
|
Deng H, Lim B. Protocol to quantify the rate of RNA polymerase II elongation with MS2/MCP- and PP7/PCP-based live-imaging systems in early Drosophila embryos. STAR Protoc 2024; 5:103099. [PMID: 38824639 PMCID: PMC11176837 DOI: 10.1016/j.xpro.2024.103099] [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: 02/22/2024] [Revised: 04/20/2024] [Accepted: 05/09/2024] [Indexed: 06/04/2024] Open
Abstract
The MS2-PP7 two-color live-imaging system provides insights into the spatiotemporal dynamics of nascent transcripts at tagged loci. Here, we present a protocol to quantitatively measure the rate of RNA polymerase II elongation for each actively transcribing nucleus in living Drosophila embryos. The elongation rate is calculated by measuring the effective distance and the time elapsed between MS2 and PP7 trajectories. We describe steps for preparing embryo samples, performing live imaging, and measuring the elongation rate. For complete details on the use and execution of this protocol, please refer to Keller et al.1.
Collapse
Affiliation(s)
- Hao Deng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bomyi Lim
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
14
|
Hosseini SH, Roussel MR. Analytic delay distributions for a family of gene transcription models. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2024; 21:6225-6262. [PMID: 39176425 DOI: 10.3934/mbe.2024273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
Models intended to describe the time evolution of a gene network must somehow include transcription, the DNA-templated synthesis of RNA, and translation, the RNA-templated synthesis of proteins. In eukaryotes, the DNA template for transcription can be very long, often consisting of tens of thousands of nucleotides, and lengthy pauses may punctuate this process. Accordingly, transcription can last for many minutes, in some cases hours. There is a long history of introducing delays in gene expression models to take the transcription and translation times into account. Here we study a family of detailed transcription models that includes initiation, elongation, and termination reactions. We establish a framework for computing the distribution of transcription times, and work out these distributions for some typical cases. For elongation, a fixed delay is a good model provided elongation is fast compared to initiation and termination, and there are no sites where long pauses occur. The initiation and termination phases of the model then generate a nontrivial delay distribution, and elongation shifts this distribution by an amount corresponding to the elongation delay. When initiation and termination are relatively fast, the distribution of elongation times can be approximated by a Gaussian. A convolution of this Gaussian with the initiation and termination time distributions gives another analytic approximation to the transcription time distribution. If there are long pauses during elongation, because of the modularity of the family of models considered, the elongation phase can be partitioned into reactions generating a simple delay (elongation through regions where there are no long pauses), and reactions whose distribution of waiting times must be considered explicitly (initiation, termination, and motion through regions where long pauses are likely). In these cases, the distribution of transcription times again involves a nontrivial part and a shift due to fast elongation processes.
Collapse
Affiliation(s)
- S Hossein Hosseini
- Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Marc R Roussel
- Alberta RNA Research and Training Institute, Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| |
Collapse
|
15
|
Sood V, Holewinski R, Andresson T, Larson DR, Misteli T. Identification of molecular determinants of gene-specific bursting patterns by high-throughput imaging screens. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.597999. [PMID: 38903099 PMCID: PMC11188098 DOI: 10.1101/2024.06.08.597999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Stochastic transcriptional bursting is a universal property of active genes. While different genes exhibit distinct bursting patterns, the molecular mechanisms for gene-specific stochastic bursting are largely unknown. We have developed and applied a high-throughput-imaging based screening strategy to identify cellular factors and molecular mechanisms that determine the bursting behavior of human genes. Focusing on epigenetic regulators, we find that protein acetylation is a strong acute modulator of burst frequency, burst size and heterogeneity of bursting. Acetylation globally affects the Off-time of genes but has gene-specific effects on the On-time. Yet, these effects are not strongly linked to promoter acetylation, which do not correlate with bursting properties, and forced promoter acetylation has variable effects on bursting. Instead, we demonstrate acetylation of the Integrator complex as a key determinant of gene bursting. Specifically, we find that elevated Integrator acetylation decreases bursting frequency. Taken together our results suggest a prominent role of non-histone proteins in determining gene bursting properties, and they identify histone-independent acetylation of a transcription cofactor as an allosteric modulator of bursting via a far-downstream bursting checkpoint.
Collapse
Affiliation(s)
- Varun Sood
- National Cancer Institute, Bethesda, MD, USA
| | - Ronald Holewinski
- Protein Characterization Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Thorkell Andresson
- Protein Characterization Laboratory, National Cancer Institute, Frederick, MD, USA
| | | | - Tom Misteli
- National Cancer Institute, Bethesda, MD, USA
| |
Collapse
|
16
|
Zheng R, Dunlap M, Bobkov GOM, Gonzalez-Figueroa C, Patel KJ, Lyu J, Harvey SE, Chan TW, Quinones-Valdez G, Choudhury M, Le Roux CA, Bartels MD, Vuong A, Flynn RA, Chang HY, Van Nostrand EL, Xiao X, Cheng C. hnRNPM protects against the dsRNA-mediated interferon response by repressing LINE-associated cryptic splicing. Mol Cell 2024; 84:2087-2103.e8. [PMID: 38815579 PMCID: PMC11204102 DOI: 10.1016/j.molcel.2024.05.004] [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: 02/24/2023] [Revised: 01/09/2024] [Accepted: 05/07/2024] [Indexed: 06/01/2024]
Abstract
RNA splicing is pivotal in post-transcriptional gene regulation, yet the exponential expansion of intron length in humans poses a challenge for accurate splicing. Here, we identify hnRNPM as an essential RNA-binding protein that suppresses cryptic splicing through binding to deep introns, maintaining human transcriptome integrity. Long interspersed nuclear elements (LINEs) in introns harbor numerous pseudo splice sites. hnRNPM preferentially binds at intronic LINEs to repress pseudo splice site usage for cryptic splicing. Remarkably, cryptic exons can generate long dsRNAs through base-pairing of inverted ALU transposable elements interspersed among LINEs and consequently trigger an interferon response, a well-known antiviral defense mechanism. Significantly, hnRNPM-deficient tumors show upregulated interferon-associated pathways and elevated immune cell infiltration. These findings unveil hnRNPM as a guardian of transcriptome integrity by repressing cryptic splicing and suggest that targeting hnRNPM in tumors may be used to trigger an inflammatory immune response, thereby boosting cancer surveillance.
Collapse
Affiliation(s)
- Rong Zheng
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mikayla Dunlap
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Georg O M Bobkov
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Carlos Gonzalez-Figueroa
- Department of Integrative Biology and Physiology and the Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Khushali J Patel
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jingyi Lyu
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Samuel E Harvey
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Tracey W Chan
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Giovanni Quinones-Valdez
- Department of Integrative Biology and Physiology and the Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mudra Choudhury
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Charlotte A Le Roux
- Verna & Marrs McLean Department of Biochemistry & Molecular Pharmacology and Therapeutic Innovation Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mason D Bartels
- Verna & Marrs McLean Department of Biochemistry & Molecular Pharmacology and Therapeutic Innovation Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Amy Vuong
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ryan A Flynn
- Center for Personal Dynamic Regulome, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulome, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Eric L Van Nostrand
- Verna & Marrs McLean Department of Biochemistry & Molecular Pharmacology and Therapeutic Innovation Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xinshu Xiao
- Department of Integrative Biology and Physiology and the Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Chonghui Cheng
- Lester & Sue Smith Breast Center, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
17
|
Yuan X, Sabzvar MK, Patil AD, Chinnaswamy K, Howie KL, Andhavaram R, Wang B, Siegler MA, Dumaz A, Stuckey JA, Corey SJ, Maciejewski JP, Visconte V, Yang CY. Comprehensive Analyses of the Effects of the Small-Molecule Inhibitor of the UHM Domain in the Splicing Factor U2AF1 in Leukemia Cells. RESEARCH SQUARE 2024:rs.3.rs-4477663. [PMID: 38883705 PMCID: PMC11177969 DOI: 10.21203/rs.3.rs-4477663/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Mutations in RNA splicing factor genes including SF3B1, U2AF1, SRSF2, and ZRSR2 have been reported to contribute to development of myeloid neoplasms including myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (sAML). Chemical tools targeting cells carrying these mutant genes remain limited and underdeveloped. Among the four proteins, mutant U2AF1 (U2AF1mut) acquires an altered 3' splice site selection preference and co-operates with the wild-type U2AF1 (U2AF1wt) to change various gene isoform patterns to support MDS cells survival and proliferation. U2AF1 mutations in MDS cells are always heterozygous and the cell viability is reduced when exposed to additional insult affecting U2AF1wt function. To investigate if the pharmacological inhibition of U2AF1wt function can provoke drug-induced vulnerability of cells harboring U2AF1 mut , we conducted a fragment-based library screening campaign to discover compounds targeting the U2AF homology domain (UHM) in U2AF1 that is required for the formation of the U2AF1/U2AF2 complex to define the 3' splice site. The most promising hit (SF1-8) selectively inhibited growth of leukemia cell lines overexpressingU2AF1 mut and human primary MDS cells carrying U2AF1 mut . RNA-seq analysis of K562-U2AF1mut following treatment with SF1-8 further revealed alteration of isoform patterns for a set of proteins that impair or rescue pathways associated with endocytosis, intracellular vesicle transport, and secretion. Our data suggested that further optimization of SF1-8 is warranted to obtain chemical probes that can be used to evaluate the therapeutic concept of inducing lethality to U2AF1 mut cells by inhibiting the U2AF1wt protein.
Collapse
Affiliation(s)
- Xinrui Yuan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Mona Kazemi Sabzvar
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Amol D Patil
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | | | - Kathryn L Howie
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Ramaraju Andhavaram
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Borwyn Wang
- Departments of Pediatrics and Cancer Biology, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Maxime A Siegler
- Department of Chemistry, John Hopkins University, Baltimore, MD, 21218, USA
| | - Arda Dumaz
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jeanne A Stuckey
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Seth J Corey
- Departments of Pediatrics and Cancer Biology, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Jaroslaw P Maciejewski
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Valeria Visconte
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Chao-Yie Yang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| |
Collapse
|
18
|
Merens HE, Choquet K, Baxter-Koenigs AR, Churchman LS. Timing is everything: advances in quantifying splicing kinetics. Trends Cell Biol 2024:S0962-8924(24)00070-9. [PMID: 38777664 DOI: 10.1016/j.tcb.2024.03.007] [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: 12/07/2023] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 05/25/2024]
Abstract
Splicing is a highly regulated process critical for proper pre-mRNA maturation and the maintenance of a healthy cellular environment. Splicing events are impacted by ongoing transcription, neighboring splicing events, and cis and trans regulatory factors on the respective pre-mRNA transcript. Within this complex regulatory environment, splicing kinetics have the potential to influence splicing outcomes but have historically been challenging to study in vivo. In this review, we highlight recent technological advancements that have enabled measurements of global splicing kinetics and of the variability of splicing kinetics at single introns. We demonstrate how identifying features that are correlated with splicing kinetics has increased our ability to form potential models for how splicing kinetics may be regulated in vivo.
Collapse
Affiliation(s)
- Hope E Merens
- Harvard University, Department of Genetics, Boston, MA, USA
| | - Karine Choquet
- University of Sherbrooke, Department of Biochemistry and Functional Genomics, Sherbrooke, Québec, Canada
| | | | | |
Collapse
|
19
|
Hermanova Z, Valihrach L, Kriska J, Maheta M, Tureckova J, Kubista M, Anderova M. The deletion of AQP4 and TRPV4 affects astrocyte swelling/volume recovery in response to ischemia-mimicking pathologies. Front Cell Neurosci 2024; 18:1393751. [PMID: 38818517 PMCID: PMC11138210 DOI: 10.3389/fncel.2024.1393751] [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: 02/29/2024] [Accepted: 05/01/2024] [Indexed: 06/01/2024] Open
Abstract
Introduction Astrocytic Transient receptor potential vanilloid 4 (TRPV4) channels, together with Aquaporin 4 (AQP4), are suspected to be the key players in cellular volume regulation, and therefore may affect the development and severity of cerebral edema during ischemia. In this study, we examined astrocytic swelling/volume recovery in mice with TRPV4 and/or AQP4 deletion in response to in vitro ischemic conditions, to determine how the deletion of these channels can affect the development of cerebral edema. Methods We used three models of ischemia-related pathological conditions: hypoosmotic stress, hyperkalemia, and oxygenglucose deprivation (OGD), and observed their effect on astrocyte volume changes in acute brain slices of Aqp4-/-, Trpv4-/- and double knockouts. In addition, we employed single-cell RT-qPCR to assess the effect of TRPV4 and AQP4 deletion on the expression of other ion channels and transporters involved in the homeostatic functioning of astrocytes. Results Quantification of astrocyte volume changes during OGD revealed that the deletion of AQP4 reduces astrocyte swelling, while simultaneous deletion of both AQP4 and TRPV4 leads to a disruption of astrocyte volume recovery during the subsequent washout. Of note, astrocyte exposure to hypoosmotic stress or hyperkalemia revealed no differences in astrocyte swelling in the absence of AQP4, TRPV4, or both channels. Moreover, under ischemia-mimicking conditions, we identified two distinct subpopulations of astrocytes with low and high volumetric responses (LRA and HRA), and their analyses revealed that mainly HRA are affected by the deletion of AQP4, TRPV4, or both channels. Furthermore, gene expression analysis revealed reduced expression of the ion transporters KCC1 and ClC2 as well as the receptors GABAB and NMDA in Trpv4-/- mice. The deletion of AQP4 instead caused reduced expression of the serine/cysteine peptidase inhibitor Serpina3n. Discussion Thus, we showed that in AQP4 or TRPV4 knockouts, not only the specific function of these channels is affected, but also the expression of other proteins, which may modulate the ischemic cascade and thus influence the final impact of ischemia.
Collapse
Affiliation(s)
- Zuzana Hermanova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine CAS, Prague, Czechia
- Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Lukas Valihrach
- Department of Cellular Neurophysiology, Institute of Experimental Medicine CAS, Prague, Czechia
- Laboratory of Gene Expression, Institute of Biotechnology CAS, Vestec, Czechia
| | - Jan Kriska
- Department of Cellular Neurophysiology, Institute of Experimental Medicine CAS, Prague, Czechia
| | - Mansi Maheta
- Laboratory of Gene Expression, Institute of Biotechnology CAS, Vestec, Czechia
| | - Jana Tureckova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine CAS, Prague, Czechia
| | - Mikael Kubista
- Laboratory of Gene Expression, Institute of Biotechnology CAS, Vestec, Czechia
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine CAS, Prague, Czechia
| |
Collapse
|
20
|
Jose AM. Heritable epigenetic changes are constrained by the dynamics of regulatory architectures. eLife 2024; 12:RP92093. [PMID: 38717010 PMCID: PMC11078544 DOI: 10.7554/elife.92093] [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] [Indexed: 05/12/2024] Open
Abstract
Interacting molecules create regulatory architectures that can persist despite turnover of molecules. Although epigenetic changes occur within the context of such architectures, there is limited understanding of how they can influence the heritability of changes. Here, I develop criteria for the heritability of regulatory architectures and use quantitative simulations of interacting regulators parsed as entities, their sensors, and the sensed properties to analyze how architectures influence heritable epigenetic changes. Information contained in regulatory architectures grows rapidly with the number of interacting molecules and its transmission requires positive feedback loops. While these architectures can recover after many epigenetic perturbations, some resulting changes can become permanently heritable. Architectures that are otherwise unstable can become heritable through periodic interactions with external regulators, which suggests that mortal somatic lineages with cells that reproducibly interact with the immortal germ lineage could make a wider variety of architectures heritable. Differential inhibition of the positive feedback loops that transmit regulatory architectures across generations can explain the gene-specific differences in heritable RNA silencing observed in the nematode Caenorhabditis elegans. More broadly, these results provide a foundation for analyzing the inheritance of epigenetic changes within the context of the regulatory architectures implemented using diverse molecules in different living systems.
Collapse
|
21
|
McShane E, Couvillion M, Ietswaart R, Prakash G, Smalec BM, Soto I, Baxter-Koenigs AR, Choquet K, Churchman LS. A kinetic dichotomy between mitochondrial and nuclear gene expression processes. Mol Cell 2024; 84:1541-1555.e11. [PMID: 38503286 PMCID: PMC11236289 DOI: 10.1016/j.molcel.2024.02.028] [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: 09/05/2023] [Revised: 12/12/2023] [Accepted: 02/27/2024] [Indexed: 03/21/2024]
Abstract
Oxidative phosphorylation (OXPHOS) complexes, encoded by both mitochondrial and nuclear DNA, are essential producers of cellular ATP, but how nuclear and mitochondrial gene expression steps are coordinated to achieve balanced OXPHOS subunit biogenesis remains unresolved. Here, we present a parallel quantitative analysis of the human nuclear and mitochondrial messenger RNA (mt-mRNA) life cycles, including transcript production, processing, ribosome association, and degradation. The kinetic rates of nearly every stage of gene expression differed starkly across compartments. Compared with nuclear mRNAs, mt-mRNAs were produced 1,100-fold more, degraded 7-fold faster, and accumulated to 160-fold higher levels. Quantitative modeling and depletion of mitochondrial factors LRPPRC and FASTKD5 identified critical points of mitochondrial regulatory control, revealing that the mitonuclear expression disparities intrinsically arise from the highly polycistronic nature of human mitochondrial pre-mRNA. We propose that resolving these differences requires a 100-fold slower mitochondrial translation rate, illuminating the mitoribosome as a nexus of mitonuclear co-regulation.
Collapse
Affiliation(s)
- Erik McShane
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Mary Couvillion
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Robert Ietswaart
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Gyan Prakash
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Brendan M Smalec
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Iliana Soto
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Autum R Baxter-Koenigs
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Karine Choquet
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
22
|
Damianov A, Lin CH, Huang J, Zhou L, Jami-Alahmadi Y, Peyda P, Wohlschlegel J, Black DL. The splicing regulators RBM5 and RBM10 are subunits of the U2 snRNP engaged with intron branch sites on chromatin. Mol Cell 2024; 84:1496-1511.e7. [PMID: 38537639 PMCID: PMC11057915 DOI: 10.1016/j.molcel.2024.02.039] [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: 09/08/2023] [Revised: 01/12/2024] [Accepted: 02/07/2024] [Indexed: 04/09/2024]
Abstract
Understanding the mechanisms of pre-mRNA splicing is limited by the technical challenges to examining spliceosomes in vivo. Here, we report the isolation of RNP complexes derived from precatalytic A or B-like spliceosomes solubilized from the chromatin pellet of mammalian cell nuclei. We found that these complexes contain U2 snRNP proteins and a portion of the U2 snRNA bound with protected RNA fragments that precisely map to intronic branch sites across the transcriptome. These U2 complexes also contained the splicing regulators RBM5 and RBM10. We found RBM5 and RBM10 bound to nearly all branch site complexes and not simply those at regulated exons. The deletion of a conserved RBM5/RBM10 peptide sequence, including a zinc finger motif, disrupted U2 interaction and rendered the proteins inactive for the repression of many alternative exons. We propose a model where RBM5 and RBM10 regulate splicing as components of the U2 snRNP complex following branch site base pairing.
Collapse
Affiliation(s)
- Andrey Damianov
- Department of Microbiology, Immunology, and Molecular Genetics, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Chia-Ho Lin
- Department of Microbiology, Immunology, and Molecular Genetics, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jeffrey Huang
- Department of Microbiology, Immunology, and Molecular Genetics, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lin Zhou
- Department of Microbiology, Immunology, and Molecular Genetics, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Parham Peyda
- Department of Microbiology, Immunology, and Molecular Genetics, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - James Wohlschlegel
- Department of Biological Chemistry, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
23
|
Coté A, O'Farrell A, Dardani I, Dunagin M, Coté C, Wan Y, Bayatpour S, Drexler HL, Alexander KA, Chen F, Wassie AT, Patel R, Pham K, Boyden ES, Berger S, Phillips-Cremins J, Churchman LS, Raj A. Post-transcriptional splicing can occur in a slow-moving zone around the gene. eLife 2024; 12:RP91357. [PMID: 38577979 PMCID: PMC10997330 DOI: 10.7554/elife.91357] [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] [Indexed: 04/06/2024] Open
Abstract
Splicing is the stepwise molecular process by which introns are removed from pre-mRNA and exons are joined together to form mature mRNA sequences. The ordering and spatial distribution of these steps remain controversial, with opposing models suggesting splicing occurs either during or after transcription. We used single-molecule RNA FISH, expansion microscopy, and live-cell imaging to reveal the spatiotemporal distribution of nascent transcripts in mammalian cells. At super-resolution levels, we found that pre-mRNA formed clouds around the transcription site. These clouds indicate the existence of a transcription-site-proximal zone through which RNA move more slowly than in the nucleoplasm. Full-length pre-mRNA undergo continuous splicing as they move through this zone following transcription, suggesting a model in which splicing can occur post-transcriptionally but still within the proximity of the transcription site, thus seeming co-transcriptional by most assays. These results may unify conflicting reports of co-transcriptional versus post-transcriptional splicing.
Collapse
Affiliation(s)
- Allison Coté
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
| | - Aoife O'Farrell
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
| | - Ian Dardani
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
| | - Margaret Dunagin
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
| | - Chris Coté
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
| | - Yihan Wan
- School of Life Sciences, Westlake UniversityHangzhouChina
| | - Sareh Bayatpour
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
| | - Heather L Drexler
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Katherine A Alexander
- Department of Cell and Developmental Biology, Penn Institute of Epigenetics, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Fei Chen
- Broad Institute of MIT and HarvardCambridgeUnited States
| | - Asmamaw T Wassie
- Department of Cell and Molecular Biology, University of PennsylvaniaPhiladelphiaUnited States
| | - Rohan Patel
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
| | - Kenneth Pham
- Department of Cell and Molecular Biology, University of PennsylvaniaPhiladelphiaUnited States
| | - Edward S Boyden
- Departments of Biological Engineering and Brain and Cognitive Sciences, Media Lab and McGovern Institute, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Shelly Berger
- Department of Cell and Developmental Biology, Penn Institute of Epigenetics, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | | | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical SchoolBostonUnited States
| | - Arjun Raj
- Department of Bioengineering, University of PennsylvaniaPhiladelphiaUnited States
- Department of Genetics, Perelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
| |
Collapse
|
24
|
Shin S, Shi G, Cho HW, Thirumalai D. Transcription-induced active forces suppress chromatin motion. Proc Natl Acad Sci U S A 2024; 121:e2307309121. [PMID: 38489381 PMCID: PMC10963020 DOI: 10.1073/pnas.2307309121] [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: 05/02/2023] [Accepted: 02/06/2024] [Indexed: 03/17/2024] Open
Abstract
The organization of interphase chromosomes in a number of species is starting to emerge thanks to advances in a variety of experimental techniques. However, much less is known about the dynamics, especially in the functional states of chromatin. Some experiments have shown that the motility of individual loci in human interphase chromosome decreases during transcription and increases upon inhibiting transcription. This is a counterintuitive finding because it is thought that the active mechanical force (F) on the order of ten piconewtons, generated by RNA polymerase II (RNAPII) that is presumably transmitted to the gene-rich region of the chromatin, would render it more open, thus enhancing the mobility. We developed a minimal active copolymer model for interphase chromosomes to investigate how F affects the dynamical properties of chromatin. The movements of the loci in the gene-rich region are suppressed in an intermediate range of F and are enhanced at small F values, which has also been observed in experiments. In the intermediate F, the bond length between consecutive loci increases, becoming commensurate with the distance at the minimum of the attractive interaction between nonbonded loci. This results in a transient disorder-to-order transition, leading to a decreased mobility during transcription. Strikingly, the F-dependent change in the locus dynamics preserves the organization of the chromosome at [Formula: see text]. Transient ordering of the loci, which is not found in the polymers with random epigenetic profiles, in the gene-rich region might be a plausible mechanism for nucleating a dynamic network involving transcription factors, RNAPII, and chromatin.
Collapse
Affiliation(s)
- Sucheol Shin
- Department of Chemistry, The University of Texas at Austin, Austin, TX78712
| | - Guang Shi
- Department of Chemistry, The University of Texas at Austin, Austin, TX78712
- Department of Materials Science, University of Illinois, Urbana, IL61801
| | - Hyun Woo Cho
- Department of Fine Chemistry and Center for Functional Biomaterials, Seoul National University of Science and Technology, Seoul01811, Republic of Korea
| | - D. Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, TX78712
- Department of Physics, The University of Texas at Austin, Austin, TX78712
| |
Collapse
|
25
|
Meeussen JVW, Lenstra TL. Time will tell: comparing timescales to gain insight into transcriptional bursting. Trends Genet 2024; 40:160-174. [PMID: 38216391 PMCID: PMC10860890 DOI: 10.1016/j.tig.2023.11.003] [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: 09/13/2023] [Revised: 11/27/2023] [Accepted: 11/27/2023] [Indexed: 01/14/2024]
Abstract
Recent imaging studies have captured the dynamics of regulatory events of transcription inside living cells. These events include transcription factor (TF) DNA binding, chromatin remodeling and modification, enhancer-promoter (E-P) proximity, cluster formation, and preinitiation complex (PIC) assembly. Together, these molecular events culminate in stochastic bursts of RNA synthesis, but their kinetic relationship remains largely unclear. In this review, we compare the timescales of upstream regulatory steps (input) with the kinetics of transcriptional bursting (output) to generate mechanistic models of transcription dynamics in single cells. We highlight open questions and potential technical advances to guide future endeavors toward a quantitative and kinetic understanding of transcription regulation.
Collapse
Affiliation(s)
- Joseph V W Meeussen
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066CX, The Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, The Netherlands Cancer Institute, Oncode Institute, Amsterdam 1066CX, The Netherlands.
| |
Collapse
|
26
|
Duan C, Mooney T, Buerer L, Bowers C, Rong S, Kim SW, Fredericks AM, Monaghan SF, Fairbrother WG. The unusual gene architecture of polyubiquitin is created by dual-specific splice sites. Genome Biol 2024; 25:33. [PMID: 38268025 PMCID: PMC10809524 DOI: 10.1186/s13059-023-03157-8] [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: 06/28/2023] [Accepted: 12/21/2023] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND The removal of introns occurs through the splicing of a 5' splice site (5'ss) with a 3' splice site (3'ss). These two elements are recognized by distinct components of the spliceosome. However, introns in higher eukaryotes contain many matches to the 5' and 3' splice-site motifs that are presumed not to be used. RESULTS Here, we find that many of these sites can be used. We also find occurrences of the AGGT motif that can function as either a 5'ss or a 3'ss-previously referred to as dual-specific splice sites (DSSs)-within introns. Analysis of the Sequence Read Archive reveals a 3.1-fold enrichment of DSSs relative to expectation, implying synergy between the ability to function as a 5'ss and 3'ss. Despite this suggested mechanistic advantage, DSSs are 2.7- and 4.7-fold underrepresented in annotated 5' and 3' splice sites. A curious exception is the polyubiquitin gene UBC, which contains a tandem array of DSSs that precisely delimit the boundary of each ubiquitin monomer. The resulting isoforms splice stochastically to include a variable number of ubiquitin monomers. We found no evidence of tissue-specific or feedback regulation but note the 8.4-fold enrichment of DSS-spliced introns in tandem repeat genes suggests a driving role in the evolution of genes like UBC. CONCLUSIONS We find an excess of unannotated splice sites and the utilization of DSSs in tandem repeats supports the role of splicing in gene evolution. These findings enhance our understanding of the diverse and complex nature of the splicing process.
Collapse
Affiliation(s)
- Chaorui Duan
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Truman Mooney
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Luke Buerer
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Cory Bowers
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, 02903, USA
| | - Stephen Rong
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, 02903, USA
- Center for Computational Molecular Biology, Brown University, Providence, RI, 02903, USA
| | - Seong Won Kim
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, 02903, USA
| | | | - Sean F Monaghan
- Division of Surgical Research, Department of Surgery, Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, 02903, USA
| | - William G Fairbrother
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, 02903, USA.
- Center for Computational Molecular Biology, Brown University, Providence, RI, 02903, USA.
| |
Collapse
|
27
|
Jose AM. Heritable epigenetic changes are constrained by the dynamics of regulatory architectures. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544138. [PMID: 37333369 PMCID: PMC10274868 DOI: 10.1101/2023.06.07.544138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Interacting molecules create regulatory architectures that can persist despite turnover of molecules. Although epigenetic changes occur within the context of such architectures, there is limited understanding of how they can influence the heritability of changes. Here I develop criteria for the heritability of regulatory architectures and use quantitative simulations of interacting regulators parsed as entities, their sensors and the sensed properties to analyze how architectures influence heritable epigenetic changes. Information contained in regulatory architectures grows rapidly with the number of interacting molecules and its transmission requires positive feedback loops. While these architectures can recover after many epigenetic perturbations, some resulting changes can become permanently heritable. Such stable changes can (1) alter steady-state levels while preserving the architecture, (2) induce different architectures that persist for many generations, or (3) collapse the entire architecture. Architectures that are otherwise unstable can become heritable through periodic interactions with external regulators, which suggests that the evolution of mortal somatic lineages with cells that reproducibly interact with the immortal germ lineage could make a wider variety of regulatory architectures heritable. Differential inhibition of the positive feedback loops that transmit regulatory architectures across generations can explain the gene-specific differences in heritable RNA silencing observed in the nematode C. elegans, which range from permanent silencing to recovery from silencing within a few generations and subsequent resistance to silencing. More broadly, these results provide a foundation for analyzing the inheritance of epigenetic changes within the context of the regulatory architectures implemented using diverse molecules in different living systems.
Collapse
|
28
|
Theil AF, Pines A, Kalayci T, Heredia‐Genestar JM, Raams A, Rietveld MH, Sridharan S, Tanis SEJ, Mulder KW, Büyükbabani N, Karaman B, Uyguner ZO, Kayserili H, Hoeijmakers JHJ, Lans H, Demmers JAA, Pothof J, Altunoglu U, El Ghalbzouri A, Vermeulen W. Trichothiodystrophy-associated MPLKIP maintains DBR1 levels for proper lariat debranching and ectodermal differentiation. EMBO Mol Med 2023; 15:e17973. [PMID: 37800682 PMCID: PMC10630875 DOI: 10.15252/emmm.202317973] [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: 05/10/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 10/07/2023] Open
Abstract
The brittle hair syndrome Trichothiodystrophy (TTD) is characterized by variable clinical features, including photosensitivity, ichthyosis, growth retardation, microcephaly, intellectual disability, hypogonadism, and anaemia. TTD-associated mutations typically cause unstable mutant proteins involved in various steps of gene expression, severely reducing steady-state mutant protein levels. However, to date, no such link to instability of gene-expression factors for TTD-associated mutations in MPLKIP/TTDN1 has been established. Here, we present seven additional TTD individuals with MPLKIP mutations from five consanguineous families, with a newly identified MPLKIP variant in one family. By mass spectrometry-based interaction proteomics, we demonstrate that MPLKIP interacts with core splicing factors and the lariat debranching protein DBR1. MPLKIP-deficient primary fibroblasts have reduced steady-state DBR1 protein levels. Using Human Skin Equivalents (HSEs), we observed impaired keratinocyte differentiation associated with compromised splicing and eventually, an imbalanced proteome affecting skin development and, interestingly, also the immune system. Our data show that MPLKIP, through its DBR1 stabilizing role, is implicated in mRNA splicing, which is of particular importance in highly differentiated tissue.
Collapse
Affiliation(s)
- Arjan F Theil
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Alex Pines
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Tuğba Kalayci
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
| | | | - Anja Raams
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Marion H Rietveld
- Department of DermatologyLeiden University Medical Center (LUMC)LeidenThe Netherlands
| | - Sriram Sridharan
- Cancer Science Institute of SingaporeNational University of SingaporeSingaporeSingapore
| | - Sabine EJ Tanis
- Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life SciencesRadboud UniversityNijmegenThe Netherlands
| | - Klaas W Mulder
- Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life SciencesRadboud UniversityNijmegenThe Netherlands
| | - Nesimi Büyükbabani
- Department of Pathology, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Medical GeneticsKoc University HospitalIstanbulTurkey
| | - Birsen Karaman
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Pediatric Basic Sciences, Child Health InstituteIstanbul UniversityIstanbulTurkey
| | - Zehra O Uyguner
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
| | - Hülya Kayserili
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Medical GeneticsKoc University School of Medicine (KUSOM)IstanbulTurkey
| | - Jan HJ Hoeijmakers
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
- Institute for Genome Stability in Aging and Disease, CECAD ForschungszentrumUniversity Hospital of CologneKölnGermany
- Princess Máxima Center for Pediatric OncologyONCODE InstituteUtrechtThe Netherlands
| | - Hannes Lans
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | | | - Joris Pothof
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| | - Umut Altunoglu
- Department of Medical Genetics, Istanbul Faculty of MedicineIstanbul UniversityIstanbulTurkey
- Department of Medical GeneticsKoc University School of Medicine (KUSOM)IstanbulTurkey
| | | | - Wim Vermeulen
- Department of Molecular GeneticsErasmus MC Cancer InstituteRotterdamThe Netherlands
| |
Collapse
|
29
|
Keikhosravi A, Almansour F, Bohrer CH, Fursova NA, Guin K, Sood V, Misteli T, Larson DR, Pegoraro G. HiTIPS: High-Throughput Image Processing Software for the Study of Nuclear Architecture and Gene Expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.02.565366. [PMID: 38076967 PMCID: PMC10705580 DOI: 10.1101/2023.11.02.565366] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/14/2024]
Abstract
High-throughput imaging (HTI) generates complex imaging datasets from a large number of experimental perturbations. Commercial HTI software for image analysis workflows does not allow full customization and adoption of new image processing algorithms in the analysis modules. While open-source HTI analysis platforms provide individual modules in the workflow, like nuclei segmentation, spot detection, or cell tracking, they are often limited in integrating novel analysis modules or algorithms. Here, we introduce the High-Throughput Image Processing Software (HiTIPS) to expand the range and customization of existing HTI analysis capabilities. HiTIPS incorporates advanced image processing and machine learning algorithms for automated cell and nuclei segmentation, spot signal detection, nucleus tracking, spot tracking, and quantification of spot signal intensity. Furthermore, HiTIPS features a graphical user interface that is open to integration of new algorithms for existing analysis pipelines and to adding new analysis pipelines through separate plugins. To demonstrate the utility of HiTIPS, we present three examples of image analysis workflows for high-throughput DNA FISH, immunofluorescence (IF), and live-cell imaging of transcription in single cells. Altogether, we demonstrate that HiTIPS is a user-friendly, flexible, and open-source HTI analysis platform for a variety of cell biology applications.
Collapse
|
30
|
Keller SH, Deng H, Lim B. Regulation of the dynamic RNA Pol II elongation rate in Drosophila embryos. Cell Rep 2023; 42:113225. [PMID: 37837623 PMCID: PMC10842316 DOI: 10.1016/j.celrep.2023.113225] [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: 06/29/2022] [Revised: 08/20/2023] [Accepted: 09/22/2023] [Indexed: 10/16/2023] Open
Abstract
An increasing number of studies have shown the key role that RNA polymerase II (RNA Pol II) elongation plays in gene regulation. We systematically examine how various enhancers, promoters, and gene body composition influence the RNA Pol II elongation rate through a single-cell-resolution live imaging assay. By using reporter constructs containing 5' MS2 and 3' PP7 repeating stem loops, we quantify the rate of RNA Pol II elongation in live Drosophila embryos. We find that promoters and exonic gene lengths have no effect on elongation rate, while enhancers and the presence of long introns may significantly change how quickly RNA Pol II moves across a gene. Furthermore, we observe in multiple constructs that the RNA Pol II elongation rate accelerates after the transcriptional onset of nuclear cycle 14 in Drosophila embryos. Our study provides a single-cell view of various mechanisms that affect the dynamic RNA Pol II elongation rate, ultimately affecting the rate of mRNA production.
Collapse
Affiliation(s)
- Samuel H Keller
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hao Deng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bomyi Lim
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
31
|
Ntini E, Budach S, Vang Ørom UA, Marsico A. Genome-wide measurement of RNA dissociation from chromatin classifies transcripts by their dynamics and reveals rapid dissociation of enhancer lncRNAs. Cell Syst 2023; 14:906-922.e6. [PMID: 37857083 DOI: 10.1016/j.cels.2023.09.005] [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: 10/30/2022] [Revised: 05/24/2023] [Accepted: 09/20/2023] [Indexed: 10/21/2023]
Abstract
Long non-coding RNAs (lncRNAs) are involved in gene expression regulation in cis. Although enriched in the cell chromatin fraction, to what degree this defines their regulatory potential remains unclear. Furthermore, the factors underlying lncRNA chromatin tethering, as well as the molecular basis of efficient lncRNA chromatin dissociation and its impact on enhancer activity and target gene expression, remain to be resolved. Here, we developed chrTT-seq, which combines the pulse-chase metabolic labeling of nascent RNA with chromatin fractionation and transient transcriptome sequencing to follow nascent RNA transcripts from their transcription on chromatin to release and allows the quantification of dissociation dynamics. By incorporating genomic, transcriptomic, and epigenetic metrics, as well as RNA-binding protein propensities, in machine learning models, we identify features that define transcript groups of different chromatin dissociation dynamics. Notably, lncRNAs transcribed from enhancers display reduced chromatin retention, suggesting that, in addition to splicing, their chromatin dissociation may shape enhancer activity.
Collapse
Affiliation(s)
- Evgenia Ntini
- Max-Planck Institute for Molecular Genetics, 14195 Berlin, Germany; Freie Universität Berlin, 14195 Berlin, Germany; Institute of Molecular Biology and Biotechnology, IMBB-FORTH, 70013 Heraklio, Greece.
| | - Stefan Budach
- Max-Planck Institute for Molecular Genetics, 14195 Berlin, Germany; Freie Universität Berlin, 14195 Berlin, Germany
| | - Ulf A Vang Ørom
- Aarhus University, Department of Molecular Biology and Genetics, 8000 Aarhus, Denmark
| | - Annalisa Marsico
- Max-Planck Institute for Molecular Genetics, 14195 Berlin, Germany; Freie Universität Berlin, 14195 Berlin, Germany; Computational Health Center, Helmholtz Center Munich, Munich, Germany.
| |
Collapse
|
32
|
Eichenberger BT, Griesbach E, Mitchell J, Chao JA. Following the Birth, Life, and Death of mRNAs in Single Cells. Annu Rev Cell Dev Biol 2023; 39:253-275. [PMID: 37843928 DOI: 10.1146/annurev-cellbio-022723-024045] [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] [Indexed: 10/18/2023]
Abstract
Recent advances in single-molecule imaging of mRNAs in fixed and living cells have enabled the lives of mRNAs to be studied with unprecedented spatial and temporal detail. These approaches have moved beyond simply being able to observe specific events and have begun to allow an understanding of how regulation is coupled between steps in the mRNA life cycle. Additionally, these methodologies are now being applied in multicellular systems and animals to provide more nuanced insights into the physiological regulation of RNA metabolism.
Collapse
Affiliation(s)
- Bastian T Eichenberger
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland;
- University of Basel, Basel, Switzerland
| | - Esther Griesbach
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland;
| | - Jessica Mitchell
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland;
| | - Jeffrey A Chao
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland;
| |
Collapse
|
33
|
Abstract
Cells must tightly regulate their gene expression programs and yet rapidly respond to acute biochemical and biophysical cues within their environment. This information is transmitted to the nucleus through various signaling cascades, culminating in the activation or repression of target genes. Transcription factors (TFs) are key mediators of these signals, binding to specific regulatory elements within chromatin. While live-cell imaging has conclusively proven that TF-chromatin interactions are highly dynamic, how such transient interactions can have long-term impacts on developmental trajectories and disease progression is still largely unclear. In this review, we summarize our current understanding of the dynamic nature of TF functions, starting with a historical overview of early live-cell experiments. We highlight key factors that govern TF dynamics and how TF dynamics, in turn, affect downstream transcriptional bursting. Finally, we conclude with open challenges and emerging technologies that will further our understanding of transcriptional regulation.
Collapse
Affiliation(s)
- Kaustubh Wagh
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
- Department of Physics, University of Maryland, College Park, Maryland, USA;
| | - Diana A Stavreva
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, Maryland, USA;
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
| |
Collapse
|
34
|
Cameron DP, Grosser J, Ladigan S, Kuzin V, Iliopoulou E, Wiegard A, Benredjem H, Jackson K, Liffers ST, Lueong S, Cheung PF, Vangala D, Pohl M, Viebahn R, Teschendorf C, Wolters H, Usta S, Geng K, Kutter C, Arsenian-Henriksson M, Siveke JT, Tannapfel A, Schmiegel W, Hahn SA, Baranello L. Coinhibition of topoisomerase 1 and BRD4-mediated pause release selectively kills pancreatic cancer via readthrough transcription. SCIENCE ADVANCES 2023; 9:eadg5109. [PMID: 37831776 PMCID: PMC10575591 DOI: 10.1126/sciadv.adg5109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 09/13/2023] [Indexed: 10/15/2023]
Abstract
Pancreatic carcinoma lacks effective therapeutic strategies resulting in poor prognosis. Transcriptional dysregulation due to alterations in KRAS and MYC affects initiation, development, and survival of this tumor type. Using patient-derived xenografts of KRAS- and MYC-driven pancreatic carcinoma, we show that coinhibition of topoisomerase 1 (TOP1) and bromodomain-containing protein 4 (BRD4) synergistically induces tumor regression by targeting promoter pause release. Comparing the nascent transcriptome with the recruitment of elongation and termination factors, we found that coinhibition of TOP1 and BRD4 disrupts recruitment of transcription termination factors. Thus, RNA polymerases transcribe downstream of genes for hundreds of kilobases leading to readthrough transcription. This occurs during replication, perturbing replisome progression and inducing DNA damage. The synergistic effect of TOP1 + BRD4 inhibition is specific to cancer cells leaving normal cells unaffected, highlighting the tumor's vulnerability to transcriptional defects. This preclinical study provides a mechanistic understanding of the benefit of combining TOP1 and BRD4 inhibitors to treat pancreatic carcinomas addicted to oncogenic drivers of transcription and replication.
Collapse
Affiliation(s)
- Donald P. Cameron
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jan Grosser
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Swetlana Ladigan
- Ruhr University Bochum, Faculty of Medicine, Department of Molecular GI Oncology, Bochum, Germany
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Vladislav Kuzin
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Evanthia Iliopoulou
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Anika Wiegard
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Hajar Benredjem
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Kathryn Jackson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Sven T. Liffers
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | - Smiths Lueong
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | - Phyllis F. Cheung
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | - Deepak Vangala
- Ruhr University Bochum, Faculty of Medicine, Department of Molecular GI Oncology, Bochum, Germany
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Michael Pohl
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Richard Viebahn
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Surgery, Bochum, Germany
| | | | - Heiner Wolters
- Department of Visceral and General Surgery, St. Josef-Hospital, Dortmund, Germany
| | - Selami Usta
- Department of Visceral and General Surgery, St. Josef-Hospital, Dortmund, Germany
| | - Keyi Geng
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Claudia Kutter
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | | | - Jens T. Siveke
- Division of Solid Tumor Translational Oncology, German Cancer Consortium (DKTK, partner site Essen) and German Cancer Research Center, DKFZ, Heidelberg, Germany
- Bridge Institute of Experimental Tumor Therapy, West German Cancer Center, University Hospital Essen, Essen, Germany
| | | | - Wolff Schmiegel
- Ruhr University Bochum, Knappschaftskrankenhaus, Department of Internal Medicine, Bochum, Germany
| | - Stephan A. Hahn
- Ruhr University Bochum, Faculty of Medicine, Department of Molecular GI Oncology, Bochum, Germany
| | - Laura Baranello
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
35
|
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.
Collapse
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.
| |
Collapse
|
36
|
Choquet K, Baxter-Koenigs AR, Dülk SL, Smalec BM, Rouskin S, Churchman LS. Pre-mRNA splicing order is predetermined and maintains splicing fidelity across multi-intronic transcripts. Nat Struct Mol Biol 2023; 30:1064-1076. [PMID: 37443198 PMCID: PMC10653200 DOI: 10.1038/s41594-023-01035-2] [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] [Received: 07/19/2022] [Accepted: 06/13/2023] [Indexed: 07/15/2023]
Abstract
Combinatorially, intron excision within a given nascent transcript could proceed down any of thousands of paths, each of which would expose different dynamic landscapes of cis-elements and contribute to alternative splicing. In this study, we found that post-transcriptional multi-intron splicing order in human cells is largely predetermined, with most genes spliced in one or a few predominant orders. Strikingly, these orders were conserved across cell types and stages of motor neuron differentiation. Introns flanking alternatively spliced exons were frequently excised last, after their neighboring introns. Perturbations to the spliceosomal U2 snRNA altered the preferred splicing order of many genes, and these alterations were associated with the retention of other introns in the same transcript. In one gene, early removal of specific introns was sufficient to induce delayed excision of three proximal introns, and this delay was caused by two distinct cis-regulatory mechanisms. Together, our results demonstrate that multi-intron splicing order in human cells is predetermined, is influenced by a component of the spliceosome and ensures splicing fidelity across long pre-mRNAs.
Collapse
Affiliation(s)
- Karine Choquet
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | | | - Sarah-Luisa Dülk
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Brendan M Smalec
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Silvi Rouskin
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
37
|
Livingston NM, Kwon J, Valera O, Saba JA, Sinha NK, Reddy P, Nelson B, Wolfe C, Ha T, Green R, Liu J, Wu B. Bursting translation on single mRNAs in live cells. Mol Cell 2023; 83:2276-2289.e11. [PMID: 37329884 PMCID: PMC10330622 DOI: 10.1016/j.molcel.2023.05.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/27/2023] [Accepted: 05/14/2023] [Indexed: 06/19/2023]
Abstract
Stochasticity has emerged as a mechanism of gene regulation. Much of this so-called "noise" has been attributed to bursting transcription. Although bursting transcription has been studied extensively, the role of stochasticity in translation has not been fully investigated due to the lack of enabling imaging technology. In this study, we developed techniques to track single mRNAs and their translation in live cells for hours, allowing the measurement of previously uncharacterized translation dynamics. We applied genetic and pharmacological perturbations to control translation kinetics and found that, like transcription, translation is not a constitutive process but instead cycles between inactive and active states, or "bursts." However, unlike transcription, which is largely frequency-modulated, complex structures in the 5'-untranslated region alter burst amplitudes. Bursting frequency can be controlled through cap-proximal sequences and trans-acting factors such as eIF4F. We coupled single-molecule imaging with stochastic modeling to quantitatively determine the kinetic parameters of translational bursting.
Collapse
Affiliation(s)
- Nathan M Livingston
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jiwoong Kwon
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Oliver Valera
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - James A Saba
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Niladri K Sinha
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pranav Reddy
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Blake Nelson
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Clara Wolfe
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Jian Liu
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Bin Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Cell Dynamics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
38
|
Busselez J, Uzbekov RE, Franco B, Pancione M. New insights into the centrosome-associated spliceosome components as regulators of ciliogenesis and tissue identity. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1776. [PMID: 36717357 DOI: 10.1002/wrna.1776] [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: 06/06/2022] [Revised: 12/20/2022] [Accepted: 12/27/2022] [Indexed: 02/01/2023]
Abstract
Biomolecular condensates are membrane-less assemblies of proteins and nucleic acids. Centrosomes are biomolecular condensates that play a crucial role in nuclear division, cytoskeletal remodeling, and cilia formation in animal cells. Spatial omics technology is providing new insights into the dynamic exchange of spliceosome components between the nucleus and the centrosome/cilium. Intriguingly, centrosomes are emerging as cytoplasmic sites for information storage, enriched with RNA molecules and RNA-processing proteins. Furthermore, growing evidence supports the view that nuclear spliceosome components assembled at the centrosome function as potential coordinators of splicing subprograms, pluripotency, and cell differentiation. In this article, we first discuss the current understanding of the centrosome/cilium complex, which controls both stem cell differentiation and pluripotency. We next explore the molecular mechanisms that govern splicing factor assembly and disassembly around the centrosome and examine how RNA processing pathways contribute to ciliogenesis. Finally, we discuss numerous unresolved compelling questions regarding the centrosome-associated spliceosome components and transcript variants within the cytoplasm as sources of RNA-based secondary messages in the regulation of cell identity and cell fate determination. This article is categorized under: RNA-Based Catalysis > RNA Catalysis in Splicing and Translation RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Processing > Splicing Regulation/Alternative Splicing RNA Processing > RNA Processing.
Collapse
Affiliation(s)
- Johan Busselez
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch-Graffenstaden, France
| | - Rustem E Uzbekov
- Faculté de Médecine, Université de Tours, Tours, France
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
- Department of Translational Medicine, Medical Genetics, University of Naples "Federico II", Naples, Italy
- Scuola Superiore Meridionale (SSM, School of Advanced Studies), Genomics and Experimental Medicine program, University of Naples Federico II, Naples, Italy
| | - Massimo Pancione
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Complutense University Madrid, Madrid, Spain
| |
Collapse
|
39
|
Hoppe ER, Udy DB, Bradley RK. Recursive splicing discovery using lariats in total RNA sequencing. Life Sci Alliance 2023; 6:e202201889. [PMID: 37137707 PMCID: PMC10156609 DOI: 10.26508/lsa.202201889] [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: 12/23/2022] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/05/2023] Open
Abstract
Recursive splicing is a non-canonical splicing mechanism in which an intron is removed in segments via multiple splicing reactions. Relatively few recursive splice sites have been identified with high confidence in human introns, and more comprehensive analyses are needed to better characterize where recursive splicing happens and whether or not it has a regulatory function. In this study, we use an unbiased approach using intron lariats to search for recursive splice sites in constitutive introns and alternative exons in the human transcriptome. We find evidence for recursive splicing in a broader range of intron sizes than previously reported and detail a new location for recursive splicing at the distal ends of cassette exons. In addition, we identify evidence for the conservation of these recursive splice sites among higher vertebrates and the use of these sites to influence alternative exon exclusion. Together, our data demonstrate the prevalence of recursive splicing and its potential influence on gene expression through alternatively spliced isoforms.
Collapse
Affiliation(s)
- Emma R Hoppe
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Dylan B Udy
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Robert K Bradley
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| |
Collapse
|
40
|
Leyes Porello EA, Trudeau RT, Lim B. Transcriptional bursting: stochasticity in deterministic development. Development 2023; 150:dev201546. [PMID: 37337971 PMCID: PMC10323239 DOI: 10.1242/dev.201546] [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] [Indexed: 06/21/2023]
Abstract
The transcription of DNA by RNA polymerase occurs as a discontinuous process described as transcriptional bursting. This bursting behavior is observed across species and has been quantified using various stochastic modeling approaches. There is a large body of evidence that suggests the bursts are actively modulated by transcriptional machinery and play a role in regulating developmental processes. Under a commonly used two-state model of transcription, various enhancer-, promoter- and chromatin microenvironment-associated features are found to differentially influence the size and frequency of bursting events - key parameters of the two-state model. Advancement of modeling and analysis tools has revealed that the simple two-state model and associated parameters may not sufficiently characterize the complex relationship between these features. The majority of experimental and modeling findings support the view of bursting as an evolutionarily conserved transcriptional control feature rather than an unintended byproduct of the transcription process. Stochastic transcriptional patterns contribute to enhanced cellular fitness and execution of proper development programs, which posit this mode of transcription as an important feature in developmental gene regulation. In this Review, we present compelling examples of the role of transcriptional bursting in development and explore the question of how stochastic transcription leads to deterministic organism development.
Collapse
Affiliation(s)
- Emilia A. Leyes Porello
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert T. Trudeau
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bomyi Lim
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
41
|
Gerber A, van Otterdijk S, Bruggeman FJ, Tutucci E. Understanding spatiotemporal coupling of gene expression using single molecule RNA imaging technologies. Transcription 2023; 14:105-126. [PMID: 37050882 PMCID: PMC10807504 DOI: 10.1080/21541264.2023.2199669] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/30/2023] [Accepted: 04/01/2023] [Indexed: 04/14/2023] Open
Abstract
Across all kingdoms of life, gene regulatory mechanisms underlie cellular adaptation to ever-changing environments. Regulation of gene expression adjusts protein synthesis and, in turn, cellular growth. Messenger RNAs are key molecules in the process of gene expression. Our ability to quantitatively measure mRNA expression in single cells has improved tremendously over the past decades. This revealed an unexpected coordination between the steps that control the life of an mRNA, from transcription to degradation. Here, we provide an overview of the state-of-the-art imaging approaches for measurement and quantitative understanding of gene expression, starting from the early visualizations of single genes by electron microscopy to current fluorescence-based approaches in single cells, including live-cell RNA-imaging approaches to FISH-based spatial transcriptomics across model organisms. We also highlight how these methods have shaped our current understanding of the spatiotemporal coupling between transcriptional and post-transcriptional events in prokaryotes. We conclude by discussing future challenges of this multidisciplinary field.Abbreviations: mRNA: messenger RNA; rRNA: ribosomal rDNA; tRNA: transfer RNA; sRNA: small RNA; FISH: fluorescence in situ hybridization; RNP: ribonucleoprotein; smFISH: single RNA molecule FISH; smiFISH: single molecule inexpensive FISH; HCR-FISH: Hybridization Chain-Reaction-FISH; RCA: Rolling Circle Amplification; seqFISH: Sequential FISH; MERFISH: Multiplexed error robust FISH; UTR: Untranslated region; RBP: RNA binding protein; FP: fluorescent protein; eGFP: enhanced GFP, MCP: MS2 coat protein; PCP: PP7 coat protein; MB: Molecular beacons; sgRNA: single guide RNA.
Collapse
Affiliation(s)
- Alan Gerber
- Amsterdam UMC, Location Vrije Universiteit Amsterdam, Department of Neurosurgery, Amsterdam, The Netherlands
- Cancer Center Amsterdam, Brain Tumor Center Amsterdam, Amsterdam, The Netherlands
| | - Sander van Otterdijk
- Systems Biology Lab, A-LIFE department, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Frank J. Bruggeman
- Systems Biology Lab, A-LIFE department, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Evelina Tutucci
- Systems Biology Lab, A-LIFE department, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
42
|
Carilli M, Gorin G, Choi Y, Chari T, Pachter L. Biophysical modeling with variational autoencoders for bimodal, single-cell RNA sequencing data. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.13.523995. [PMID: 36712140 PMCID: PMC9882246 DOI: 10.1101/2023.01.13.523995] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We motivate and present biVI, which combines the variational autoencoder framework of scVI with biophysically motivated, bivariate models for nascent and mature RNA distributions. While previous approaches to integrate bimodal data via the variational autoencoder framework ignore the causal relationship between measurements, biVI models the biophysical processes that give rise to observations. We demonstrate through simulated benchmarking that biVI captures cell type structure in a low-dimensional space and accurately recapitulates parameter values and copy number distributions. On biological data, biVI provides a scalable route for identifying the biophysical mechanisms underlying gene expression. This analytical approach outlines a generalizable strategy for treating multimodal datasets generated by high-throughput, single-cell genomic assays.
Collapse
Affiliation(s)
- Maria Carilli
- Division of Biology and Biological Engineering, California Institute of Technology
| | - Gennady Gorin
- Division of Chemistry and Chemical Engineering, California Institute of Technology
| | - Yongin Choi
- Biomedical Engineering Graduate Group, University of California, Davis
- Genome Center, University of California, Davis
| | - Tara Chari
- Division of Biology and Biological Engineering, California Institute of Technology
| | - Lior Pachter
- Division of Biology and Biological Engineering, California Institute of Technology
- Department of Computing and Mathematical Sciences, California Institute of Technology
| |
Collapse
|
43
|
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: 50] [Impact Index Per Article: 50.0] [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.
Collapse
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.
| |
Collapse
|
44
|
Franz A, Weber AI, Preußner M, Dimos N, Stumpf A, Ji Y, Moreno-Velasquez L, Voigt A, Schulz F, Neumann A, Kuropka B, Kühn R, Urlaub H, Schmitz D, Wahl MC, Heyd F. Branch point strength controls species-specific CAMK2B alternative splicing and regulates LTP. Life Sci Alliance 2023; 6:6/3/e202201826. [PMID: 36543542 PMCID: PMC9772828 DOI: 10.26508/lsa.202201826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Regulation and functionality of species-specific alternative splicing has remained enigmatic to the present date. Calcium/calmodulin-dependent protein kinase IIβ (CaMKIIβ) is expressed in several splice variants and plays a key role in learning and memory. Here, we identify and characterize several primate-specific CAMK2B splice isoforms, which show altered kinetic properties and changes in substrate specificity. Furthermore, we demonstrate that primate-specific CAMK2B alternative splicing is achieved through branch point weakening during evolution. We show that reducing branch point and splice site strengths during evolution globally renders constitutive exons alternative, thus providing novel mechanistic insight into cis-directed species-specific alternative splicing regulation. Using CRISPR/Cas9, we introduce a weaker, human branch point sequence into the mouse genome, resulting in strongly altered Camk2b splicing in the brains of mutant mice. We observe a strong impairment of long-term potentiation in CA3-CA1 synapses of mutant mice, thus connecting branch point-controlled CAMK2B alternative splicing with a fundamental function in learning and memory.
Collapse
Affiliation(s)
- Andreas Franz
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Berlin, Germany.,Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of Structural Biochemistry, Berlin, Germany
| | - A Ioana Weber
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Berlin, Germany
| | - Marco Preußner
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Berlin, Germany
| | - Nicole Dimos
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of Structural Biochemistry, Berlin, Germany
| | - Alexander Stumpf
- Neuroscience Research Centre (NWFZ), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Yanlong Ji
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.,Hematology/Oncology, Department of Medicine II, Johann Wolfgang Goethe University, Frankfurt am Main, Germany.,Frankfurt Cancer Institute, Goethe University, Frankfurt am Main, Germany
| | - Laura Moreno-Velasquez
- Neuroscience Research Centre (NWFZ), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Anne Voigt
- Neuroscience Research Centre (NWFZ), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Frederic Schulz
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Berlin, Germany
| | - Alexander Neumann
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Berlin, Germany
| | - Benno Kuropka
- Freie Universität Berlin, Mass Spectrometry Core Facility (BioSupraMol), Berlin, Germany
| | - Ralf Kühn
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Genome Engineering & Disease Models, Berlin, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.,Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Dietmar Schmitz
- Neuroscience Research Centre (NWFZ), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Markus C Wahl
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of Structural Biochemistry, Berlin, Germany.,Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany
| | - Florian Heyd
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of RNA Biochemistry, Berlin, Germany
| |
Collapse
|
45
|
Bohrer CH, Larson DR. Synthetic analysis of chromatin tracing and live-cell imaging indicates pervasive spatial coupling between genes. eLife 2023; 12:e81861. [PMID: 36790144 PMCID: PMC9984193 DOI: 10.7554/elife.81861] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
The role of the spatial organization of chromosomes in directing transcription remains an outstanding question in gene regulation. Here, we analyze two recent single-cell imaging methodologies applied across hundreds of genes to systematically analyze the contribution of chromosome conformation to transcriptional regulation. Those methodologies are (1) single-cell chromatin tracing with super-resolution imaging in fixed cells; and (2) high-throughput labeling and imaging of nascent RNA in living cells. Specifically, we determine the contribution of physical distance to the coordination of transcriptional bursts. We find that individual genes adopt a constrained conformation and reposition toward the centroid of the surrounding chromatin upon activation. Leveraging the variability in distance inherent in single-cell imaging, we show that physical distance - but not genomic distance - between genes on individual chromosomes is the major factor driving co-bursting. By combining this analysis with live-cell imaging, we arrive at a corrected transcriptional correlation of [Formula: see text] for genes separated by < 400 nm. We propose that this surprisingly large correlation represents a physical property of human chromosomes and establishes a benchmark for future experimental studies.
Collapse
Affiliation(s)
- Christopher H Bohrer
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of HealthBethesdaUnited States
| | - Daniel R Larson
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of HealthBethesdaUnited States
| |
Collapse
|
46
|
Wu S, Schmitz U. Single-cell and long-read sequencing to enhance modelling of splicing and cell-fate determination. Comput Struct Biotechnol J 2023; 21:2373-2380. [PMID: 37066125 PMCID: PMC10091034 DOI: 10.1016/j.csbj.2023.03.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/13/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Single-cell sequencing technologies have revolutionised the life sciences and biomedical research. Single-cell sequencing provides high-resolution data on cell heterogeneity, allowing high-fidelity cell type identification, and lineage tracking. Computational algorithms and mathematical models have been developed to make sense of the data, compensate for errors and simulate the biological processes, which has led to breakthroughs in our understanding of cell differentiation, cell-fate determination and tissue cell composition. The development of long-read (a.k.a. third-generation) sequencing technologies has produced powerful tools for investigating alternative splicing, isoform expression (at the RNA level), genome assembly and the detection of complex structural variants (at the DNA level). In this review, we provide an overview of the recent advancements in single-cell and long-read sequencing technologies, with a particular focus on the computational algorithms that help in correcting, analysing, and interpreting the resulting data. Additionally, we review some mathematical models that use single-cell and long-read sequencing data to study cell-fate determination and alternative splicing, respectively. Moreover, we highlight the emerging opportunities in modelling cell-fate determination that result from the combination of single-cell and long-read sequencing technologies.
Collapse
|
47
|
Luo S, Wang Z, Zhang Z, Zhou T, Zhang J. Genome-wide inference reveals that feedback regulations constrain promoter-dependent transcriptional burst kinetics. Nucleic Acids Res 2022; 51:68-83. [PMID: 36583343 PMCID: PMC9874261 DOI: 10.1093/nar/gkac1204] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/06/2022] [Accepted: 12/06/2022] [Indexed: 12/31/2022] Open
Abstract
Gene expression in mammalian cells is highly variable and episodic, resulting in a series of discontinuous bursts of mRNAs. A challenge is to understand how static promoter architecture and dynamic feedback regulations dictate bursting on a genome-wide scale. Although single-cell RNA sequencing (scRNA-seq) provides an opportunity to address this challenge, effective analytical methods are scarce. We developed an interpretable and scalable inference framework, which combined experimental data with a mechanistic model to infer transcriptional burst kinetics (sizes and frequencies) and feedback regulations. Applying this framework to scRNA-seq data generated from embryonic mouse fibroblast cells, we found Simpson's paradoxes, i.e. genome-wide burst kinetics exhibit different characteristics in two cases without and with distinguishing feedback regulations. We also showed that feedbacks differently modulate burst frequencies and sizes and conceal the effects of transcription start site distributions on burst kinetics. Notably, only in the presence of positive feedback, TATA genes are expressed with high burst frequencies and enhancer-promoter interactions mainly modulate burst frequencies. The developed inference method provided a flexible and efficient way to investigate transcriptional burst kinetics and the obtained results would be helpful for understanding cell development and fate decision.
Collapse
Affiliation(s)
| | | | - Zhenquan Zhang
- Guangdong Province Key Laboratory of Computational Science, Sun Yat-sen University, Guangzhou, 510275, P. R. China,School of Mathematics, Sun Yat-sen University, Guangzhou, Guangdong Province, 510275, P. R. China
| | - Tianshou Zhou
- Correspondence may also be addressed to Tianshou Zhou. Tel: +86 20 84134958;
| | - Jiajun Zhang
- To whom correspondence should be addressed. Tel: +86 20 84111829;
| |
Collapse
|
48
|
Boe RH, Ayyappan V, Schuh L, Raj A. Allelic correlation is a marker of trade-offs between barriers to transmission of expression variability and signal responsiveness in genetic networks. Cell Syst 2022; 13:1016-1032.e6. [PMID: 36450286 PMCID: PMC9811561 DOI: 10.1016/j.cels.2022.10.008] [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: 12/23/2021] [Revised: 06/28/2022] [Accepted: 10/28/2022] [Indexed: 12/03/2022]
Abstract
Genetic networks should respond to signals but prevent the transmission of spontaneous fluctuations. Limited data from mammalian cells suggest that noise transmission is uncommon, but systematic claims about noise transmission have been limited by the inability to directly measure it. Here, we build a mathematical framework modeling allelic correlation and noise transmission, showing that allelic correlation and noise transmission correspond across model parameters and network architectures. Limiting noise transmission comes with the trade-off of being unresponsive to signals, and within responsive regimes, there is a further trade-off between response time and basal noise transmission. Analysis of allele-specific single-cell RNA-sequencing data revealed that genes encoding upstream factors in signaling pathways and cell-type-specific factors have higher allelic correlation than downstream factors, suggesting they are more subject to regulation. Overall, our findings suggest that some noise transmission must result from signal responsiveness, but it can be minimized by trading off for a slower response. A record of this paper's transparent peer review process is included in the supplemental information.
Collapse
Affiliation(s)
- Ryan H Boe
- Genetics and Epigenetics, Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Vinay Ayyappan
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA
| | - Lea Schuh
- Institute of AI for Health, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany; Department of Mathematics, Technical University of Munich, Garching 85748, Germany
| | - Arjun Raj
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
49
|
Zeng Y, Fair BJ, Zeng H, Krishnamohan A, Hou Y, Hall JM, Ruthenburg AJ, Li YI, Staley JP. Profiling lariat intermediates reveals genetic determinants of early and late co-transcriptional splicing. Mol Cell 2022; 82:4681-4699.e8. [PMID: 36435176 PMCID: PMC10448999 DOI: 10.1016/j.molcel.2022.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 09/10/2022] [Accepted: 11/02/2022] [Indexed: 11/27/2022]
Abstract
Long introns with short exons in vertebrate genes are thought to require spliceosome assembly across exons (exon definition), rather than introns, thereby requiring transcription of an exon to splice an upstream intron. Here, we developed CoLa-seq (co-transcriptional lariat sequencing) to investigate the timing and determinants of co-transcriptional splicing genome wide. Unexpectedly, 90% of all introns, including long introns, can splice before transcription of a downstream exon, indicating that exon definition is not obligatory for most human introns. Still, splicing timing varies dramatically across introns, and various genetic elements determine this variation. Strong U2AF2 binding to the polypyrimidine tract predicts early splicing, explaining exon definition-independent splicing. Together, our findings question the essentiality of exon definition and reveal features beyond intron and exon length that are determinative for splicing timing.
Collapse
Affiliation(s)
- Yi Zeng
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Benjamin J Fair
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Huilin Zeng
- 855 Jefferson Ave. Redwood City, CA 94063, USA
| | - Aiswarya Krishnamohan
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Yichen Hou
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Johnathon M Hall
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Alexander J Ruthenburg
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA; Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Yang I Li
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA; Department of Human Genetics, University of Chicago, Chicago, IL 60637, USA.
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA.
| |
Collapse
|
50
|
David JK, Maden SK, Wood MA, Thompson RF, Nellore A. Retained introns in long RNA-seq reads are not reliably detected in sample-matched short reads. Genome Biol 2022; 23:240. [PMID: 36369064 PMCID: PMC9652823 DOI: 10.1186/s13059-022-02789-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/10/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND There is growing interest in retained introns in a variety of disease contexts including cancer and aging. Many software tools have been developed to detect retained introns from short RNA-seq reads, but reliable detection is complicated by overlapping genes and transcripts as well as the presence of unprocessed or partially processed RNAs. RESULTS We compared introns detected by 8 tools using short RNA-seq reads with introns observed in long RNA-seq reads from the same biological specimens. We found significant disagreement among tools (Fleiss' [Formula: see text]) such that 47.7% of all detected intron retentions were not called by more than one tool. We also observed poor performance of all tools, with none achieving an F1-score greater than 0.26, and qualitatively different behaviors between general-purpose alternative splicing detection tools and tools confined to retained intron detection. CONCLUSIONS Short-read tools detect intron retention with poor recall and precision, calling into question the completeness and validity of a large percentage of putatively retained introns called by commonly used methods.
Collapse
Affiliation(s)
- Julianne K. David
- grid.5288.70000 0000 9758 5690Computational Biology Program, Oregon Health & Science University, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR USA ,Present Address: Base5 Genomics, Inc., Mountain View, CA USA
| | - Sean K. Maden
- grid.5288.70000 0000 9758 5690Computational Biology Program, Oregon Health & Science University, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR USA ,grid.21107.350000 0001 2171 9311Present Address: Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD USA
| | - Mary A. Wood
- grid.5288.70000 0000 9758 5690Computational Biology Program, Oregon Health & Science University, Portland, OR USA ,grid.429936.30000 0004 5914 210XPortland VA Research Foundation, Portland, OR USA ,Present Address: Phase Genomics, Inc., Seattle, WA USA
| | - Reid F. Thompson
- grid.5288.70000 0000 9758 5690Computational Biology Program, Oregon Health & Science University, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR USA ,grid.484322.bDivision of Hospital and Specialty Medicine, VA Portland Healthcare System, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Radiation Medicine, Oregon Health & Science University, Portland, OR USA
| | - Abhinav Nellore
- grid.5288.70000 0000 9758 5690Computational Biology Program, Oregon Health & Science University, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Surgery, Oregon Health & Science University, Portland, OR USA
| |
Collapse
|