1
|
Werner A, Kanhere A, Wahlestedt C, Mattick JS. Natural antisense transcripts as versatile regulators of gene expression. Nat Rev Genet 2024; 25:730-744. [PMID: 38632496 DOI: 10.1038/s41576-024-00723-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2024] [Indexed: 04/19/2024]
Abstract
Long non-coding RNAs (lncRNAs) are emerging as a major class of gene products that have central roles in cell and developmental biology. Natural antisense transcripts (NATs) are an important subset of lncRNAs that are expressed from the opposite strand of protein-coding and non-coding genes and are a genome-wide phenomenon in both eukaryotes and prokaryotes. In eukaryotes, a myriad of NATs participate in regulatory pathways that affect expression of their cognate sense genes. Recent developments in the study of NATs and lncRNAs and large-scale sequencing and bioinformatics projects suggest that whether NATs regulate expression, splicing, stability or translation of the sense transcript is influenced by the pattern and degrees of overlap between the sense-antisense pair. Moreover, epigenetic gene regulatory mechanisms prevail in somatic cells whereas mechanisms dependent on the formation of double-stranded RNA intermediates are prevalent in germ cells. The modulating effects of NATs on sense transcript expression make NATs rational targets for therapeutic interventions.
Collapse
Affiliation(s)
| | | | | | - John S Mattick
- University of New South Wales, Sydney, New South Wales, Australia
| |
Collapse
|
2
|
Aiello U, Porrua O, Libri D. Sen1: the varied virtues of a multifaceted helicase. J Mol Biol 2024:168808. [PMID: 39357815 DOI: 10.1016/j.jmb.2024.168808] [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: 07/24/2024] [Revised: 09/26/2024] [Accepted: 09/26/2024] [Indexed: 10/04/2024]
Abstract
Several machineries concurrently work on the DNA, but among them RNA Polymerases (RNAPs) are the most widespread and active users. The homeostasis of such a busy genomic environment relies on the existence of mechanisms that allow to limit transcription to a functional level, both in terms of extent and rate. Sen1 is a central player in this sense: using its translocase activity this protein has evolved the specific function of dislodging RNAPs from the DNA template, thus ending the transcription cycle. Over the years, studies have shown that Sen1 uses this same mechanism in a multitude of situations, allowing termination of all three eukaryotic RNAPs in different contexts. In virtue of its helicase activity, Sen1 has also been proposed to have a prominent function in the resolution of co-transcriptional genotoxic R-loops, which can cause the stalling of replication forks. In this review, we provide a synopsis of past and recent findings on the functions of Sen1 in yeast and of its human homologue Senataxin (SETX).
Collapse
Affiliation(s)
- Umberto Aiello
- Department of Genetics, Stanford University School of Medicine, Stanford, CA
| | - Odil Porrua
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| | - Domenico Libri
- Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France
| |
Collapse
|
3
|
Cheah HL, Citartan M, Lee LP, Ahmed SA, Salleh MZ, Teh LK, Tang TH. Exploring the transcription start sites and other genomic features facilitates the accurate identification and annotation of small RNAs across multiple stress conditions in Mycobacterium tuberculosis. Funct Integr Genomics 2024; 24:160. [PMID: 39264475 DOI: 10.1007/s10142-024-01437-5] [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: 08/22/2024] [Accepted: 08/23/2024] [Indexed: 09/13/2024]
Abstract
Mycobacterium tuberculosis (MTB) is a pathogen that is known for its ability to persist in harsh environments and cause chronic infections. Understanding the regulatory networks of MTB is crucial for developing effective treatments. Small regulatory RNAs (sRNAs) play important roles in gene expression regulation in all kingdoms of life, and their classification based solely on genomic location can be imprecise due to the computational-based prediction of protein-coding genes in bacteria, which often neglects segments of mRNA such as 5'UTRs, 3'UTRs, and intercistronic regions of operons. To address this issue, our study simultaneously discovered genomic features such as TSSs, UTRs, and operons together with sRNAs in the M. tuberculosis H37Rv strain (ATCC 27294) across multiple stress conditions. Our analysis identified 1,376 sRNA candidates and 8,173 TSSs in MTB, providing valuable insights into its complex regulatory landscape. TSS mapping enabled us to classify these sRNAs into more specific categories, including promoter-associated sRNAs, 5'UTR-derived sRNAs, 3'UTR-derived sRNAs, true intergenic sRNAs, and antisense sRNAs. Three of these sRNA candidates were experimentally validated using 3'-RACE-PCR: predictedRNA_0240, predictedRNA_0325, and predictedRNA_0578. Future characterization and validation are necessary to fully elucidate the functions and roles of these sRNAs in MTB. Our study is the first to simultaneously unravel TSSs and sRNAs in MTB and demonstrate that the identification of other genomic features, such as TSSs, UTRs, and operons, allows for more accurate and specific classification of sRNAs.
Collapse
Affiliation(s)
- Hong-Leong Cheah
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia
- Monash University Malaysia Genomics Platform, School of Science, Monash University Malaysia, Bandar Sunway, 47500, Subang Jaya, Selangor, Malaysia
| | - Marimuthu Citartan
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia.
| | - Li-Pin Lee
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia
| | - Siti Aminah Ahmed
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia
| | - Mohd Zaki Salleh
- Integrative Pharmacogenomics Institute (iPROMISE), Universiti Teknologi MARA (UiTM) Selangor, Bandar Puncak Alam, Selangor, Malaysia
- Faculty of Pharmacy, Universiti Teknologi MARA (UiTM) Selangor, Bandar Puncak Alam, Selangor, Malaysia
| | - Lay Kek Teh
- Integrative Pharmacogenomics Institute (iPROMISE), Universiti Teknologi MARA (UiTM) Selangor, Bandar Puncak Alam, Selangor, Malaysia
- Faculty of Pharmacy, Universiti Teknologi MARA (UiTM) Selangor, Bandar Puncak Alam, Selangor, Malaysia
| | - Thean-Hock Tang
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia.
| |
Collapse
|
4
|
Sibai DS, Tremblay MG, Lessard F, Tav C, Sabourin-Félix M, Robinson M, Moss T. TTF1 control of LncRNA synthesis delineates a tumor suppressor pathway directly regulating the ribosomal RNA genes. J Cell Physiol 2024; 239:e31303. [PMID: 38764354 DOI: 10.1002/jcp.31303] [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: 03/15/2024] [Revised: 04/29/2024] [Accepted: 05/02/2024] [Indexed: 05/21/2024]
Abstract
The tumor suppressor p14/19ARF regulates ribosomal RNA (rRNA) synthesis by controlling the nucleolar localization of Transcription Termination Factor 1 (TTF1). However, the role played by TTF1 in regulating the rRNA genes and in potentially controlling growth has remained unclear. We now show that TTF1 expression regulates cell growth by determining the cellular complement of ribosomes. Unexpectedly, it achieves this by acting as a "roadblock" to synthesis of the noncoding LncRNA and pRNA that we show are generated from the "Spacer Promoter" duplications present upstream of the 47S pre-rRNA promoter on the mouse and human ribosomal RNA genes. Unexpectedly, the endogenous generation of these noncoding RNAs does not induce CpG methylation or gene silencing. Rather, it acts in cis to suppress 47S preinitiation complex formation and hence de novo pre-rRNA synthesis by a mechanism reminiscent of promoter interference or occlusion. Taken together, our data delineate a pathway from p19ARF to cell growth suppression via the regulation of ribosome biogenesis by noncoding RNAs and validate a key cellular growth law in mammalian cells.
Collapse
Affiliation(s)
- Dany S Sibai
- St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Laval University, Quebec City, Quebec, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec City, Quebec, Canada
- Cancer Research Centre, Laval University, Quebec City, Quebec, Canada
| | - Michel G Tremblay
- St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Laval University, Quebec City, Quebec, Canada
| | - Frédéric Lessard
- St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Laval University, Quebec City, Quebec, Canada
| | - Christophe Tav
- St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Laval University, Quebec City, Quebec, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec City, Quebec, Canada
- Cancer Research Centre, Laval University, Quebec City, Quebec, Canada
| | - Marianne Sabourin-Félix
- St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Laval University, Quebec City, Quebec, Canada
| | - Mark Robinson
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Tom Moss
- St-Patrick Research Group in Basic Oncology, Cancer Division of the Quebec University Hospital Research Centre, Laval University, Quebec City, Quebec, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Faculty of Medicine, Laval University, Quebec City, Quebec, Canada
- Cancer Research Centre, Laval University, Quebec City, Quebec, Canada
| |
Collapse
|
5
|
Tian X, Volkovinskiy A, Marchisio MA. RNAi-based Boolean gates in the yeast Saccharomyces cerevisiae. Front Bioeng Biotechnol 2024; 12:1392967. [PMID: 38895554 PMCID: PMC11184144 DOI: 10.3389/fbioe.2024.1392967] [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: 02/28/2024] [Accepted: 05/06/2024] [Indexed: 06/21/2024] Open
Abstract
Boolean gates, the fundamental components of digital circuits, have been widely investigated in synthetic biology because they permit the fabrication of biosensors and facilitate biocomputing. This study was conducted to design and construct Boolean gates in the yeast Saccharomyces cerevisiae, the main component of which was the RNA interference pathway (RNAi) that is naturally absent from the budding yeast cells. We tested different expression cassettes for the siRNA precursor (a giant hairpin sequence, a DNA fragment-flanked by one or two introns-between convergent promoters or transcribed separately in the sense and antisense directions) and placed different components under the control of the circuit inputs (i.e., the siRNA precursor or proteins such as the Dicer and the Argonaute). We found that RNAi-based logic gates are highly sensitive to promoter leakage and, for this reason, challenging to implement in vivo. Convergent-promoter architecture turned out to be the most reliable solution, even though the overall best performance was achieved with the most difficult design based on the siRNA precursor as a giant hairpin.
Collapse
Affiliation(s)
- Ximing Tian
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
| | - Andrey Volkovinskiy
- School of Life Science and Technology, Harbin Institute of Technology, Harbin, China
| | | |
Collapse
|
6
|
Mowery CT, Freimer JW, Chen Z, Casaní-Galdón S, Umhoefer JM, Arce MM, Gjoni K, Daniel B, Sandor K, Gowen BG, Nguyen V, Simeonov DR, Garrido CM, Curie GL, Schmidt R, Steinhart Z, Satpathy AT, Pollard KS, Corn JE, Bernstein BE, Ye CJ, Marson A. Systematic decoding of cis gene regulation defines context-dependent control of the multi-gene costimulatory receptor locus in human T cells. Nat Genet 2024; 56:1156-1167. [PMID: 38811842 PMCID: PMC11176074 DOI: 10.1038/s41588-024-01743-5] [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: 12/20/2022] [Accepted: 04/04/2024] [Indexed: 05/31/2024]
Abstract
Cis-regulatory elements (CREs) interact with trans regulators to orchestrate gene expression, but how transcriptional regulation is coordinated in multi-gene loci has not been experimentally defined. We sought to characterize the CREs controlling dynamic expression of the adjacent costimulatory genes CD28, CTLA4 and ICOS, encoding regulators of T cell-mediated immunity. Tiling CRISPR interference (CRISPRi) screens in primary human T cells, both conventional and regulatory subsets, uncovered gene-, cell subset- and stimulation-specific CREs. Integration with CRISPR knockout screens and assay for transposase-accessible chromatin with sequencing (ATAC-seq) profiling identified trans regulators influencing chromatin states at specific CRISPRi-responsive elements to control costimulatory gene expression. We then discovered a critical CCCTC-binding factor (CTCF) boundary that reinforces CRE interaction with CTLA4 while also preventing promiscuous activation of CD28. By systematically mapping CREs and associated trans regulators directly in primary human T cell subsets, this work overcomes longstanding experimental limitations to decode context-dependent gene regulatory programs in a complex, multi-gene locus critical to immune homeostasis.
Collapse
Grants
- P30 DK063720 NIDDK NIH HHS
- R01 HG008140 NHGRI NIH HHS
- T32 GM007618 NIGMS NIH HHS
- S10 OD028511 NIH HHS
- F99 CA234842 NCI NIH HHS
- S10 OD021822 NIH HHS
- K00 CA234842 NCI NIH HHS
- P01 AI138962 NIAID NIH HHS
- U01 HL157989 NHLBI NIH HHS
- R01 DK129364 NIDDK NIH HHS
- T32 DK007418 NIDDK NIH HHS
- R01 AI136972 NIAID NIH HHS
- F30 AI157167 NIAID NIH HHS
- R01 HG011239 NHGRI NIH HHS
- NIH grants 1R01DK129364-01A1, P01AI138962, and R01HG008140; the Larry L. Hillblom Foundation (grant no. 2020-D-002-NET); and Northern California JDRF Center of Excellence. A.M. is a member of the Parker Institute for Cancer Immunotherapy (PICI), and has received funding from the Arc Institute, Chan Zuckerberg Biohub, Innovative Genomics Institute (IGI), Cancer Research Institute (CRI) Lloyd J. Old STAR award, a gift from the Jordan Family, a gift from the Byers family and a gift from B. Bakar.
- UCSF ImmunoX Computational Immunology Fellow, is supported by NIH grant F30AI157167, and has received support from NIH grants T32DK007418 and T32GM007618
- NIH grant R01HG008140
- Career Award for Medical Scientists from the Burroughs Wellcome Fund, a Lloyd J. Old STAR Award from the Cancer Research Institute, and the Parker Institute for Cancer Immunotherapy
- NIH grant U01HL157989
Collapse
Affiliation(s)
- Cody T Mowery
- Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Jacob W Freimer
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Zeyu Chen
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA, USA
| | - Salvador Casaní-Galdón
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA, USA
| | - Jennifer M Umhoefer
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Maya M Arce
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Ketrin Gjoni
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
| | - Bence Daniel
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Pathology, Stanford University, Stanford, CA, USA
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
- Department of Microchemistry, Proteomics, Lipidomics and Next Generation Sequencing, Genentech, South San Francisco, CA, USA
| | - Katalin Sandor
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Pathology, Stanford University, Stanford, CA, USA
| | - Benjamin G Gowen
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Vinh Nguyen
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
- UCSF CoLabs, University of California, San Francisco, San Francisco, CA, USA
| | - Dimitre R Simeonov
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Christian M Garrido
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Gemma L Curie
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Ralf Schmidt
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Zachary Steinhart
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Ansuman T Satpathy
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Department of Pathology, Stanford University, Stanford, CA, USA
- Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA
- Program in Immunology, Stanford University, Stanford, CA, USA
| | - Katherine S Pollard
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub SF, San Francisco, CA, USA
| | - Jacob E Corn
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Bradley E Bernstein
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Departments of Cell Biology and Pathology, Harvard Medical School, Boston, MA, USA
| | - Chun Jimmie Ye
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA.
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.
- Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA.
- Chan Zuckerberg Biohub SF, San Francisco, CA, USA.
- Rosalind Russell/Ephraim P. Engleman Rheumatology Research Center, University of California, San Francisco, San Francisco, CA, USA.
- Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA, USA.
- Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA.
| | - Alexander Marson
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA.
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA.
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA.
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA.
- Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA.
- Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA.
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA.
| |
Collapse
|
7
|
Moyung K, Li Y, Hartemink AJ, MacAlpine DM. Genome-wide nucleosome and transcription factor responses to genetic perturbations reveal chromatin-mediated mechanisms of transcriptional regulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595391. [PMID: 38826400 PMCID: PMC11142231 DOI: 10.1101/2024.05.24.595391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Epigenetic mechanisms contribute to gene regulation by altering chromatin accessibility through changes in transcription factor (TF) and nucleosome occupancy throughout the genome. Despite numerous studies focusing on changes in gene expression, the intricate chromatin-mediated regulatory code remains largely unexplored on a comprehensive scale. We address this by employing a factor-agnostic, reverse-genetics approach that uses MNase-seq to capture genome-wide TF and nucleosome occupancies in response to the individual deletion of 201 transcriptional regulators in Saccharomyces cerevisiae, thereby assaying nearly one million mutant-gene interactions. We develop a principled approach to identify and quantify chromatin changes genome-wide, observing differences in TF and nucleosome occupancy that recapitulate well-established pathways identified by gene expression data. We also discover distinct chromatin signatures associated with the up- and downregulation of genes, and use these signatures to reveal regulatory mechanisms previously unexplored in expression-based studies. Finally, we demonstrate that chromatin features are predictive of transcriptional activity and leverage these features to reconstruct chromatin-based transcriptional regulatory networks. Overall, these results illustrate the power of an approach combining genetic perturbation with high-resolution epigenomic profiling; the latter enables a close examination of the interplay between TFs and nucleosomes genome-wide, providing a deeper, more mechanistic understanding of the complex relationship between chromatin organization and transcription.
Collapse
Affiliation(s)
- Kevin Moyung
- Program in Computational Biology and Bioinformatics, Duke University, Durham, NC 27708
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Yulong Li
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
- Department of Computer Science, Duke University, Durham, NC 27708
| | - Alexander J. Hartemink
- Program in Computational Biology and Bioinformatics, Duke University, Durham, NC 27708
- Department of Computer Science, Duke University, Durham, NC 27708
| | - David M. MacAlpine
- Program in Computational Biology and Bioinformatics, Duke University, Durham, NC 27708
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| |
Collapse
|
8
|
Hao JD, Liu QL, Liu MX, Yang X, Wang LM, Su SY, Xiao W, Zhang MQ, Zhang YC, Zhang L, Chen YS, Yang YG, Ren J. DDX21 mediates co-transcriptional RNA m 6A modification to promote transcription termination and genome stability. Mol Cell 2024; 84:1711-1726.e11. [PMID: 38569554 DOI: 10.1016/j.molcel.2024.03.006] [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: 06/14/2023] [Revised: 02/09/2024] [Accepted: 03/11/2024] [Indexed: 04/05/2024]
Abstract
N6-methyladenosine (m6A) is a crucial RNA modification that regulates diverse biological processes in human cells, but its co-transcriptional deposition and functions remain poorly understood. Here, we identified the RNA helicase DDX21 with a previously unrecognized role in directing m6A modification on nascent RNA for co-transcriptional regulation. DDX21 interacts with METTL3 for co-recruitment to chromatin through its recognition of R-loops, which can be formed co-transcriptionally as nascent transcripts hybridize onto the template DNA strand. Moreover, DDX21's helicase activity is needed for METTL3-mediated m6A deposition onto nascent RNA following recruitment. At transcription termination regions, this nexus of actions promotes XRN2-mediated termination of RNAPII transcription. Disruption of any of these steps, including the loss of DDX21, METTL3, or their enzymatic activities, leads to defective termination that can induce DNA damage. Therefore, we propose that the R-loop-DDX21-METTL3 nexus forges the missing link for co-transcriptional modification of m6A, coordinating transcription termination and genome stability.
Collapse
Affiliation(s)
- Jin-Dong Hao
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qian-Lan Liu
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Meng-Xia Liu
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Xing Yang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liu-Ming Wang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Si-Yi Su
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Xiao
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meng-Qi Zhang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi-Chang Zhang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lan Zhang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Yu-Sheng Chen
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun-Gui Yang
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.
| | - Jie Ren
- Key Laboratory of RNA Science and Engineering, CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.
| |
Collapse
|
9
|
Uriu K, Hernandez-Sanchez JP, Kojima S. Impacts of the feedback loop between sense-antisense RNAs in regulating circadian rhythms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.28.591560. [PMID: 38746188 PMCID: PMC11092440 DOI: 10.1101/2024.04.28.591560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Antisense transcripts are a unique group of non-coding RNAs that are transcribed from the opposite strand of a sense coding gene in an antisense orientation. Even though they do not encode a protein, these transcripts play a regulatory role in a variety of biological processes, including circadian rhythms. We and others found an antisense transcript, Per2AS , that is transcribed from the strand opposite the sense transcript Period2 ( Per2 ) and exhibits a rhythmic and antiphasic expression pattern compared to Per2 in mouse. By assuming that Per2AS and Per2 mutually repress each other, our previous mathematical model predicted that Per2AS regulates the robustness and the amplitude of circadian rhythms. In this study, we revised our previous model and developed a new mathematical model that mechanistically described the mutually repressive relationship between Per2 and Per2AS via transcriptional interference. We found that the simulation results are largely consistent with experimental observations including the counterintuitive ones that could not be fully explained by our previous model. These results indicate that our revised model serves as a foundation to build more detailed models in the future to better understand the impact of Per2AS-Per2 interaction in the mammalian circadian clock. Our mechanistic description of Per2AS-Per2 interaction can also be extended to other mathematical models that involve sense-antisense RNA pairs that mutually repress each other.
Collapse
|
10
|
Mayer A, Li J, McLaughlin G, Gladfelter A, Roper M. Mitigating transcription noise via protein sharing in syncytial cells. Biophys J 2024; 123:968-978. [PMID: 38459697 PMCID: PMC11052695 DOI: 10.1016/j.bpj.2024.03.009] [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: 11/14/2023] [Revised: 02/19/2024] [Accepted: 03/05/2024] [Indexed: 03/10/2024] Open
Abstract
Bursty transcription allows nuclei to concentrate the work of transcribing mRNA into short, intermittent intervals, potentially reducing transcriptional interference. However, bursts of mRNA production can increase noise in protein abundances. Here, we formulate models for gene expression in syncytia, or multinucleate cells, showing that protein abundance noise may be mitigated locally via spatial averaging of diffuse proteins. Our modeling shows a universal reduction in protein noise, which increases with the average number of nuclei per cell and persists even when the number of nuclei is itself a random variable. Experimental data comparing distributions of a cyclin mRNA that is conserved between brewer's yeast and a closely related filamentous fungus Ashbya gossypii confirm that syncytism is permissive of greater levels of transcriptional noise. Our findings suggest that division of transcriptional labor between nuclei allows syncytia to sidestep tradeoffs between efficiency and precision of gene expression.
Collapse
Affiliation(s)
- Alex Mayer
- Department of Mathematics, UCLA, Los Angeles, California.
| | - Jiayu Li
- Department of Mathematics, UCLA, Los Angeles, California
| | - Grace McLaughlin
- Department of Biology, Duke University, Durham, North Carolina; Department of Biology, UNC, Chapel Hill, North Carolina
| | - Amy Gladfelter
- Department of Biology, Duke University, Durham, North Carolina
| | - Marcus Roper
- Department of Mathematics, UCLA, Los Angeles, California; Department of Computational Medicine, UCLA, Los Angeles, California
| |
Collapse
|
11
|
Blanco P, Hipólito A, García-Pastor L, Trigo da Roza F, Toribio-Celestino L, Ortega A, Vergara E, San Millán Á, Escudero J. Identification of promoter activity in gene-less cassettes from Vibrionaceae superintegrons. Nucleic Acids Res 2024; 52:2961-2976. [PMID: 38214222 PMCID: PMC11014356 DOI: 10.1093/nar/gkad1252] [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: 04/18/2023] [Revised: 12/18/2023] [Accepted: 12/26/2023] [Indexed: 01/13/2024] Open
Abstract
Integrons are genetic platforms that acquire new genes encoded in integron cassettes (ICs), building arrays of adaptive functions. ICs generally encode promoterless genes, whose expression relies on the platform-associated Pc promoter, with the cassette array functioning as an operon-like structure regulated by the distance to the Pc. This is relevant in large sedentary chromosomal integrons (SCIs) carrying hundreds of ICs, like those in Vibrio species. We selected 29 gene-less cassettes in four Vibrio SCIs, and explored whether their function could be related to the transcription regulation of adjacent ICs. We show that most gene-less cassettes have promoter activity on the sense strand, enhancing the expression of downstream cassettes. Additionally, we identified the transcription start sites of gene-less ICs through 5'-RACE. Accordingly, we found that most of the superintegron in Vibrio cholerae is not silent. These promoter cassettes can trigger the expression of a silent dfrB9 cassette downstream, increasing trimethoprim resistance >512-fold in V. cholerae and Escherichia coli. Furthermore, one cassette with an antisense promoter can reduce trimethoprim resistance when cloned downstream. Our findings highlight the regulatory role of gene-less cassettes in the expression of adjacent cassettes, emphasizing their significance in SCIs and their clinical importance if captured by mobile integrons.
Collapse
Affiliation(s)
- Paula Blanco
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Alberto Hipólito
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Lucía García-Pastor
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Filipa Trigo da Roza
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Laura Toribio-Celestino
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid 28049, Spain
| | - Alba Cristina Ortega
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Ester Vergara
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Álvaro San Millán
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid 28049, Spain
- Centro de Investigación Biológica en Red de Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Madrid 28222, Spain
| | - José Antonio Escudero
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid 28040, Spain
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid 28040, Spain
| |
Collapse
|
12
|
Watanabe T, Kimura Y, Umeno D. MetJ-Based Mutually Interfering SAM-ON/SAM-OFF Biosensors. ACS Synth Biol 2024; 13:624-633. [PMID: 38286030 DOI: 10.1021/acssynbio.3c00621] [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: 01/31/2024]
Abstract
SAM (S-adenosylmethionine) is an important metabolite that operates as a major donor of methyl groups and is a controller of various physiological processes. Its availability is also believed to be a major bottleneck in the biological production of numerous high-value metabolites. Here, we constructed SAM-sensing systems using MetJ, an SAM-dependent transcriptional regulator, as a core component. SAM is a corepressor of MetJ, which suppresses the MetJ promoter with an increasing cellular concentration of SAM (SAM-OFF sensor). The application of transcriptional interference and evolutionary tuning effectively inverted its response, yielding a SAM-ON sensor (signal increases with increasing SAM concentration). By linking two genes encoding fluorescent protein reporters in such a way that their transcription events interfere with each other's and by placing one of them under the control of MetJ, we could increase the effective signal-to-noise ratio of the SAM sensor while decreasing the batch-to-batch deviation in signal output, likely by canceling out the growth-associated fluctuation in translational resources. By taking the ratio of SAM-ON/SAM-OFF signals and by resetting the default pool size of SAM, we could rapidly identify SAM synthetase (MetK) mutants with increased cellular activity from a random library. The strategy described herein should be widely applicable for identifying activity mutants, which would be otherwise overlooked because of the strong homeostasis of metabolic networks.
Collapse
Affiliation(s)
- Taro Watanabe
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Kirin Central Research Institute, Kirin Holdings Company, Limited, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Kanagawa, Japan
| | - Yuki Kimura
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Daisuke Umeno
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| |
Collapse
|
13
|
Rehman SU, Ullah N, Zhang Z, Zhen Y, Din AU, Cui H, Wang M. Recent insights into the functions and mechanisms of antisense RNA: emerging applications in cancer therapy and precision medicine. Front Chem 2024; 11:1335330. [PMID: 38274897 PMCID: PMC10809404 DOI: 10.3389/fchem.2023.1335330] [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: 11/08/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
The antisense RNA molecule is a unique DNA transcript consisting of 19-23 nucleotides, characterized by its complementary nature to mRNA. These antisense RNAs play a crucial role in regulating gene expression at various stages, including replication, transcription, and translation. Additionally, artificial antisense RNAs have demonstrated their ability to effectively modulate gene expression in host cells. Consequently, there has been a substantial increase in research dedicated to investigating the roles of antisense RNAs. These molecules have been found to be influential in various cellular processes, such as X-chromosome inactivation and imprinted silencing in healthy cells. However, it is important to recognize that in cancer cells; aberrantly expressed antisense RNAs can trigger the epigenetic silencing of tumor suppressor genes. Moreover, the presence of deletion-induced aberrant antisense RNAs can lead to the development of diseases through epigenetic silencing. One area of drug development worth mentioning is antisense oligonucleotides (ASOs), and a prime example of an oncogenic trans-acting long noncoding RNA (lncRNA) is HOTAIR (HOX transcript antisense RNA). NATs (noncoding antisense transcripts) are dysregulated in many cancers, and researchers are just beginning to unravel their roles as crucial regulators of cancer's hallmarks, as well as their potential for cancer therapy. In this review, we summarize the emerging roles and mechanisms of antisense RNA and explore their application in cancer therapy.
Collapse
Affiliation(s)
- Shahab Ur Rehman
- College of Animals Science and Technology Yangzhou University, Yangzhou, China
| | - Numan Ullah
- College of Animals Science and Technology Yangzhou University, Yangzhou, China
| | - Zhenbin Zhang
- College of Animals Science and Technology Yangzhou University, Yangzhou, China
| | - Yongkang Zhen
- College of Animals Nutrition Yangzhou University, Yangzhou, China
| | - Aziz-Ud Din
- Department of Human Genetics, Hazara University Mansehra, Mansehra, Pakistan
| | - Hengmi Cui
- College of Animals Science and Technology Yangzhou University, Yangzhou, China
- Institute of Epigenetics and Epigenomics Yangzhou University, College of Animal Nutrition Yangzhou University, Yangzhou, China
| | - Mengzhi Wang
- College of Animals Science and Technology Yangzhou University, Yangzhou, China
- College of Animals Nutrition Yangzhou University, Yangzhou, China
| |
Collapse
|
14
|
Mayer A, McLaughlin G, Gladfelter A, Glass NL, Mela A, Roper M. Syncytial Assembly Lines: Consequences of Multinucleate Cellular Compartments for Fungal Protein Synthesis. Results Probl Cell Differ 2024; 71:159-183. [PMID: 37996678 DOI: 10.1007/978-3-031-37936-9_9] [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: 11/25/2023]
Abstract
Fast growth and prodigious cellular outputs make fungi powerful tools in biotechnology. Recent modeling work has exposed efficiency gains associated with dividing the labor of transcription over multiple nuclei, and experimental innovations are opening new windows on the capacities and adaptations that allow nuclei to behave autonomously or in coordination while sharing a single, common cytoplasm. Although the motivation of our review is to motivate and connect recent work toward a greater understanding of fungal factories, we use the analogy of the assembly line as an organizing idea for studying coordinated gene expression, generally.
Collapse
Affiliation(s)
- Alex Mayer
- Department of Mathematics, University of California Los Angeles, Los Angeles, CA, USA
| | - Grace McLaughlin
- Department of Cell Biology, Duke University, Durham, NC, USA
- Department of Biology, University of North Carolina Chapel Hill, Chapel Hill, NC, USA
| | - Amy Gladfelter
- Department of Cell Biology, Duke University, Durham, NC, USA
| | - N Louise Glass
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Alexander Mela
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Marcus Roper
- Department of Mathematics, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
15
|
Boulas I, Bruno L, Rimsky S, Espeli O, Junier I, Rivoire O. Assessing in vivo the impact of gene context on transcription through DNA supercoiling. Nucleic Acids Res 2023; 51:9509-9521. [PMID: 37667073 PMCID: PMC10570042 DOI: 10.1093/nar/gkad688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 07/24/2023] [Accepted: 08/09/2023] [Indexed: 09/06/2023] Open
Abstract
Gene context can have significant impact on gene expression but is currently not integrated in quantitative models of gene regulation despite known biophysical principles and quantitative in vitro measurements. Conceptually, the simplest gene context consists of a single gene framed by two topological barriers, known as the twin transcriptional-loop model, which illustrates the interplay between transcription and DNA supercoiling. In vivo, DNA supercoiling is additionally modulated by topoisomerases, whose modus operandi remains to be quantified. Here, we bridge the gap between theory and in vivo properties by realizing in Escherichia coli the twin transcriptional-loop model and by measuring how gene expression varies with promoters and distances to the topological barriers. We find that gene expression depends on the distance to the upstream barrier but not to the downstream barrier, with a promoter-dependent intensity. We rationalize these findings with a first-principle biophysical model of DNA transcription. Our results are explained if TopoI and gyrase both act specifically, respectively upstream and downstream of the gene, with antagonistic effects of TopoI, which can repress initiation while facilitating elongation. Altogether, our work sets the foundations for a systematic and quantitative description of the impact of gene context on gene regulation.
Collapse
Affiliation(s)
- Ihab Boulas
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Lisa Bruno
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Sylvie Rimsky
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Olivier Espeli
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Ivan Junier
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France
| | - Olivier Rivoire
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Gulliver, ESPCI, CNRS, Université PSL, Paris, France
| |
Collapse
|
16
|
Zukher I, Dujardin G, Sousa-Luís R, Proudfoot NJ. Elongation roadblocks mediated by dCas9 across human genes modulate transcription and nascent RNA processing. Nat Struct Mol Biol 2023; 30:1536-1548. [PMID: 37783853 PMCID: PMC10584677 DOI: 10.1038/s41594-023-01090-9] [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: 06/14/2022] [Accepted: 08/04/2023] [Indexed: 10/04/2023]
Abstract
Non-cleaving Cas9 (dCas9) is widely employed to manipulate specific gene loci, often with scant regard for unintended transcriptional effects. We demonstrate here that dCas9 mediates precise RNA polymerase II transcriptional pausing followed by transcription termination and potential alternative polyadenylation. By contrast, alternative splicing is unaffected, likely requiring more sustained alteration to elongation speed. The effect on transcription is orientation specific, with pausing only being induced when dCas9-associated guide RNA anneals to the non-template strand. Targeting the template strand induces minimal effects on transcription elongation and thus provides a neutral approach to recruit dCas9-linked effector domains to specific gene regions. In essence, we evaluate molecular effects of targeting dCas9 to mammalian transcription units. In so doing, we also provide new information on elongation by RNA polymerase II and coupled pre-mRNA processing.
Collapse
Affiliation(s)
- Inna Zukher
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
| | - Gwendal Dujardin
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rui Sousa-Luís
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Nick J Proudfoot
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
| |
Collapse
|
17
|
Dubrovin EV. Atomic force microscopy-based approaches for single-molecule investigation of nucleic acid- protein complexes. Biophys Rev 2023; 15:1015-1033. [PMID: 37974971 PMCID: PMC10643717 DOI: 10.1007/s12551-023-01111-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/07/2023] [Indexed: 11/19/2023] Open
Abstract
The interaction of nucleic acids with proteins plays an important role in many fundamental biological processes in living cells, including replication, transcription, and translation. Therefore, understanding nucleic acid-protein interaction is of high relevance in many areas of biology, medicine and technology. During almost four decades of its existence atomic force microscopy (AFM) accumulated a significant experience in investigation of biological molecules at a single-molecule level. AFM has become a powerful tool of molecular biology and biophysics providing unique information about properties, structure, and functioning of biomolecules. Despite a great variety of nucleic acid-protein systems under AFM investigations, there are a number of typical approaches for such studies. This review is devoted to the analysis of the typical AFM-based approaches of investigation of DNA (RNA)-protein complexes with a major focus on transcription studies. The basic strategies of AFM analysis of nucleic acid-protein complexes including investigation of the products of DNA-protein reactions and real-time dynamics of DNA-protein interaction are categorized and described by the example of the most relevant research studies. The described approaches and protocols have many universal features and, therefore, are applicable for future AFM studies of various nucleic acid-protein systems.
Collapse
Affiliation(s)
- Evgeniy V. Dubrovin
- Lomonosov Moscow State University, Leninskie Gory 1 Bld. 2, 119991 Moscow, Russian Federation
- Moscow Institute of Physics and Technology, Institutskiy Per. 9, Dolgoprudny, 141700 Russian Federation
- Sirius University of Science and Technology, Olimpiyskiy Ave 1, Township Sirius, Krasnodar Region, 354349 Russia
| |
Collapse
|
18
|
Dietrich D, Jovanovic-Gasovic S, Cao P, Kohlstedt M, Wittmann C. Refactoring the architecture of a polyketide gene cluster enhances docosahexaenoic acid production in Yarrowia lipolytica through improved expression and genetic stability. Microb Cell Fact 2023; 22:199. [PMID: 37773137 PMCID: PMC10540379 DOI: 10.1186/s12934-023-02209-9] [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: 08/15/2023] [Accepted: 09/20/2023] [Indexed: 10/01/2023] Open
Abstract
BACKGROUND Long-chain polyunsaturated fatty acids (LC-PUFAs), such as docosahexaenoic acid (DHA), are essential for human health and have been widely used in the food and pharmaceutical industries. However, the limited availability of natural sources, such as oily fish, has led to the pursuit of microbial production as a promising alternative. Yarrowia lipolytica can produce various PUFAs via genetic modification. A recent study upgraded Y. lipolytica for DHA production by expressing a four-gene cluster encoding a myxobacterial PKS-like PUFA synthase, reducing the demand for redox power. However, the genetic architecture of gene expression in Y. lipolytica is complex and involves various control elements, offering space for additional improvement of DHA production. This study was designed to optimize the expression of the PUFA cluster using a modular cloning approach. RESULTS Expression of the monocistronic cluster with each gene under the control of the constitutive TEF promoter led to low-level DHA production. By using the minLEU2 promoter instead and incorporating additional upstream activating UAS1B4 sequences, 5' promoter introns, and intergenic spacers, DHA production was increased by 16-fold. The producers remained stable over 185 h of cultivation. Beneficially, the different genetic control elements acted synergistically: UAS1B elements generally increased expression, while the intron caused gene-specific effects. Mutants with UAS1B16 sequences within 2-8 kb distance, however, were found to be genetically unstable, which limited production performance over time, suggesting the avoidance of long repetitive sequence blocks in synthetic multigene clusters and careful monitoring of genetic stability in producing strains. CONCLUSIONS Overall, the results demonstrate the effectiveness of synthetic heterologous gene clusters to drive DHA production in Y. lipolytica. The combinatorial exploration of different genetic control elements allowed the optimization of DHA production. These findings have important implications for developing Y. lipolytica strains for the industrial-scale production of valuable polyunsaturated fatty acids.
Collapse
Affiliation(s)
- Demian Dietrich
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | | | - Peng Cao
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany.
| |
Collapse
|
19
|
Van Zyl WF, Van Staden AD, Dicks LMT, Trindade M. Use of the mCherry fluorescent protein to optimize the expression of class I lanthipeptides in Escherichia coli. Microb Cell Fact 2023; 22:149. [PMID: 37559122 PMCID: PMC10413542 DOI: 10.1186/s12934-023-02162-7] [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] [Received: 03/24/2023] [Accepted: 07/29/2023] [Indexed: 08/11/2023] Open
Abstract
BACKGROUND Lanthipeptides are a rapidly expanding family of ribosomally synthesized and post-translationally modified natural compounds with diverse biological functions. Lanthipeptide structural and biosynthetic genes can readily be identified in genomic datasets, which provides a substantial repository for unique peptides with a wide range of potentially novel bioactivities. To realize this potential efficiently optimized heterologous production systems are required. However, only a few class I lanthipeptides have been successfully expressed using Escherichia coli as heterologous producer. This may be attributed to difficulties experienced in the co-expression of structural genes and multiple processing genes as well as complex optimization experiments. RESULTS Here, an optimized modular plasmid system is presented for the complete biosynthesis for each of the class I lanthipeptides nisin and clausin, in E. coli. Genes encoding precursor lanthipeptides were fused to the gene encoding the mCherry red fluorescent protein and co-expressed along with the required synthetases from the respective operons. Antimicrobially active nisin and clausin were proteolytically liberated from the expressed mCherry fusions. The mCherry-NisA expression system combined with in vivo fluorescence monitoring was used to elucidate the effect of culture media composition, promoter arrangement, and culture conditions including choice of growth media and inducer agents on the heterologous expression of the class I lanthipeptides. To evaluate the promiscuity of the clausin biosynthetic enzymes, the optimized clausin expression system was used for the heterologous expression of epidermin. CONCLUSION We succeeded in developing novel mCherry-fusion based plug and play heterologous expression systems to produce two different subgroups of class I lanthipeptides. Fully modified Pre-NisA, Pre-ClausA and Pre-EpiA fused to the mCherry fluorescence gene was purified from the Gram-negative host E. coli BL21 (DE3). Our study demonstrates the potential of using in vivo fluorescence as a platform to evaluate the expression of mCherry-fused lanthipeptides in E. coli. This allowed a substantial reduction in optimization time, since expression could be monitored in real-time, without the need for extensive and laborious purification steps or the use of in vitro activity assays. The optimized heterologous expression systems developed in this study may be employed in future studies for the scalable expression of novel NisA derivatives, or novel genome mined derivatives of ClausA and other class I lanthipeptides in E. coli.
Collapse
Affiliation(s)
- Winschau F Van Zyl
- Department of Microbiology, Stellenbosch University, Cape Town, South Africa.
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein, South Africa.
| | - Anton D Van Staden
- Department of Microbiology, Stellenbosch University, Cape Town, South Africa
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Leon M T Dicks
- Department of Microbiology, Stellenbosch University, Cape Town, South Africa
| | - Marla Trindade
- Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Cape Town, South Africa
| |
Collapse
|
20
|
Wanney WC, Youssar L, Kostova G, Georg J. Improved RNA stability estimation indicates that transcriptional interference is frequent in diverse bacteria. Commun Biol 2023; 6:732. [PMID: 37454177 PMCID: PMC10349824 DOI: 10.1038/s42003-023-05097-2] [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: 03/09/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023] Open
Abstract
We used stochastic simulations and experimental data from E. coli, K. aerogenes, Synechococcus PCC 7002 and Synechocystis PCC 6803 to provide evidence that transcriptional interference via the collision mechanism is likely a prevalent mechanism for bacterial gene regulation. Rifampicin time-series data can be used to globally monitor and quantify collision between sense and antisense transcription-complexes. Our findings also highlight that transcriptional events, such as differential RNA decay, partial termination, and internal transcriptional start sites often deviate from gene annotations. Consequently, within a single gene annotation, there exist transcript segments with varying half-lives and transcriptional properties. To address these complexities, we introduce 'rifi', an R-package that analyzes transcriptomic data from rifampicin time series. 'rifi' employs a dynamic programming-based segmentation approach to identify individual transcripts, enabling accurate assessment of RNA stability and detection of diverse transcriptional events.
Collapse
Affiliation(s)
- Walja C Wanney
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- Plant Biotechnology, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Loubna Youssar
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Gergana Kostova
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Jens Georg
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
| |
Collapse
|
21
|
Hao N, Donnelly AJ, Dodd IB, Shearwin KE. When push comes to shove - RNA polymerase and DNA-bound protein roadblocks. Biophys Rev 2023; 15:355-366. [PMID: 37396453 PMCID: PMC10310618 DOI: 10.1007/s12551-023-01064-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 05/21/2023] [Indexed: 07/04/2023] Open
Abstract
In recent years, transcriptional roadblocking has emerged as a crucial regulatory mechanism in gene expression, whereby other DNA-bound obstacles can block the progression of transcribing RNA polymerase (RNAP), leading to RNAP pausing and ultimately dissociation from the DNA template. In this review, we discuss the mechanisms by which transcriptional roadblocks can impede RNAP progression, as well as how RNAP can overcome these obstacles to continue transcription. We examine different DNA-binding proteins involved in transcriptional roadblocking and their biophysical properties that determine their effectiveness in blocking RNAP progression. The catalytically dead CRISPR-Cas (dCas) protein is used as an example of an engineered programmable roadblock, and the current literature in understanding the polarity of dCas roadblocking is also discussed. Finally, we delve into a stochastic model of transcriptional roadblocking and highlight the importance of transcription factor binding kinetics and its resistance to dislodgement by an elongating RNAP in determining the strength of a roadblock.
Collapse
Affiliation(s)
- Nan Hao
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005 Australia
| | - Alana J. Donnelly
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005 Australia
| | - Ian B. Dodd
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005 Australia
| | - Keith E. Shearwin
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005 Australia
| |
Collapse
|
22
|
Yin Y, Chen G, Lin Z, Zhang D, Lin W, Luo W. Natural antisense transcript of MYOG regulates development and regeneration in skeletal muscle by shielding the binding sites of MicroRNAs of MYOG mRNA 3'UTR. Biochem Biophys Res Commun 2023; 662:93-103. [PMID: 37104884 DOI: 10.1016/j.bbrc.2023.04.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023]
Abstract
Natural antisense transcripts (NATs) are endogenous RNAs opposite to sense transcripts, and they can significantly contribute to regulating various biological processes through multiple epigenetic mechanisms. NATs can affect their sense transcripts to regulate the growth and development of skeletal muscle. Our analysis of third-generation full-length transcriptome sequencing data revealed that NATs represented a significant portion of the lncRNA, accounting for up to 30.19%-33.35%. The expression of NATs correlated with myoblast differentiation, and genes expressing NATs were mainly involved in RNA synthesis, protein transport, and cell cycle. We found a NAT of MYOG (MYOG-NAT) in the data. We found that the MYOG-NAT could promote the differentiation of myoblasts in vitro. Additionally, knockdown of MYOG-NAT in vivo led to muscle fiber atrophy and muscle regeneration retardation. Molecular biology experiments demonstrated that MYOG-NAT enhances the stability of MYOG mRNA by competing with miR-128-2-5p, miR-19a-5p, and miR-19b-5p for binding to MYOG mRNA 3'UTR. These findings suggest that MYOG-NAT plays a critical role in skeletal muscle development and provides insights into the post-transcriptional regulation of NATs.
Collapse
Affiliation(s)
- Yunqian Yin
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affair, South China Agricultural University, Guangzhou, 510642, China
| | - Genghua Chen
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affair, South China Agricultural University, Guangzhou, 510642, China
| | - Zetong Lin
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affair, South China Agricultural University, Guangzhou, 510642, China
| | - Danlu Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affair, South China Agricultural University, Guangzhou, 510642, China
| | - Wujian Lin
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affair, South China Agricultural University, Guangzhou, 510642, China
| | - Wen Luo
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, and Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture and Rural Affair, South China Agricultural University, Guangzhou, 510642, China.
| |
Collapse
|
23
|
Wang L, Watters JW, Ju X, Lu G, Liu S. Head-on and co-directional RNA polymerase collisions orchestrate bidirectional transcription termination. Mol Cell 2023; 83:1153-1164.e4. [PMID: 36917983 PMCID: PMC10081963 DOI: 10.1016/j.molcel.2023.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 01/03/2023] [Accepted: 02/15/2023] [Indexed: 03/14/2023]
Abstract
Genomic DNA is a crowded track where motor proteins frequently collide. It remains underexplored whether these collisions carry physiological function. In this work, we develop a single-molecule assay to visualize the trafficking of individual E. coli RNA polymerases (RNAPs) on DNA. Based on transcriptomic data, we hypothesize that RNAP collisions drive bidirectional transcription termination of convergent gene pairs. Single-molecule results show that the head-on collision between two converging RNAPs is necessary to prevent transcriptional readthrough but insufficient to release the RNAPs from the DNA. Remarkably, co-directional collision of a trailing RNAP into the head-on collided complex dramatically increases the termination efficiency. Furthermore, stem-loop structures formed in the nascent RNA are required for collisions to occur at well-defined positions between convergent genes. These findings suggest that physical collisions between RNAPs furnish a mechanism for transcription termination and that programmed genomic conflicts can be exploited to co-regulate the expression of multiple genes.
Collapse
Affiliation(s)
- Ling Wang
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA.
| | - John W Watters
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Xiangwu Ju
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Genzhe Lu
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA
| | - Shixin Liu
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY, USA.
| |
Collapse
|
24
|
Ghandour R, Gao Y, Laskowski J, Barahimipour R, Ruf S, Bock R, Zoschke R. Transgene insertion into the plastid genome alters expression of adjacent native chloroplast genes at the transcriptional and translational levels. PLANT BIOTECHNOLOGY JOURNAL 2023; 21:711-725. [PMID: 36529916 PMCID: PMC10037153 DOI: 10.1111/pbi.13985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 11/14/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
In plant biotechnology and basic research, chloroplasts have been used as chassis for the expression of various transgenes. However, potential unintended side effects of transgene insertion and high-level transgene expression on the expression of native chloroplast genes are often ignored and have not been studied comprehensively. Here, we examined expression of the chloroplast genome at both the transcriptional and translational levels in five transplastomic tobacco (Nicotiana tabacum) lines carrying the identical aadA resistance marker cassette in diverse genomic positions. Although none of the lines exhibits a pronounced visible phenotype, the analysis of three lines that contain the aadA insertion in different locations within the petL-petG-psaJ-rpl33-rps18 transcription unit demonstrates that transcriptional read-through from the aadA resistance marker is unavoidable, and regularly causes overexpression of downstream sense-oriented chloroplast genes at the transcriptional and translational levels. Investigation of additional lines that harbour the aadA intergenically and outside of chloroplast transcription units revealed that expression of the resistance marker can also cause antisense effects by interference with transcription/transcript accumulation and/or translation of downstream antisense-oriented genes. In addition, we provide evidence for a previously suggested role of genomically encoded tRNAs in chloroplast transcription termination and/or transcript processing. Together, our data uncover principles of neighbouring effects of chloroplast transgenes and suggest general strategies for the choice of transgene insertion sites and expression elements to minimize unintended consequences of transgene expression on the transcription and translation of native chloroplast genes.
Collapse
Affiliation(s)
- Rabea Ghandour
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| | - Yang Gao
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| | | | | | - Stephanie Ruf
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| | - Ralph Bock
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| | - Reimo Zoschke
- Max Planck Institute of Molecular Plant PhysiologyPotsdam‐GolmGermany
| |
Collapse
|
25
|
Montez M, Majchrowska M, Krzyszton M, Bokota G, Sacharowski S, Wrona M, Yatusevich R, Massana F, Plewczynski D, Swiezewski S. Promoter-pervasive transcription causes RNA polymerase II pausing to boost DOG1 expression in response to salt. EMBO J 2023; 42:e112443. [PMID: 36705062 PMCID: PMC9975946 DOI: 10.15252/embj.2022112443] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/02/2023] [Accepted: 01/09/2023] [Indexed: 01/28/2023] Open
Abstract
Eukaryotic genomes are pervasively transcribed by RNA polymerase II. Yet, the molecular and biological implications of such a phenomenon are still largely puzzling. Here, we describe noncoding RNA transcription upstream of the Arabidopsis thaliana DOG1 gene, which governs salt stress responses and is a key regulator of seed dormancy. We find that expression of the DOG1 gene is induced by salt stress, thereby causing a delay in seed germination. We uncover extensive transcriptional activity on the promoter of the DOG1 gene, which produces a variety of lncRNAs. These lncRNAs, named PUPPIES, are co-directionally transcribed and extend into the DOG1 coding region. We show that PUPPIES RNAs respond to salt stress and boost DOG1 expression, resulting in delayed germination. This positive role of pervasive PUPPIES transcription on DOG1 gene expression is associated with augmented pausing of RNA polymerase II, slower transcription and higher transcriptional burst size. These findings highlight the positive role of upstream co-directional transcription in controlling transcriptional dynamics of downstream genes.
Collapse
Affiliation(s)
- Miguel Montez
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Maria Majchrowska
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Michal Krzyszton
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Grzegorz Bokota
- Laboratory of Functional and Structural Genomics, Centre of New TechnologiesUniversity of WarsawWarsawPoland
| | - Sebastian Sacharowski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Magdalena Wrona
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Ruslan Yatusevich
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Ferran Massana
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| | - Dariusz Plewczynski
- Laboratory of Functional and Structural Genomics, Centre of New TechnologiesUniversity of WarsawWarsawPoland
- Laboratory of Bioinformatics and Computational Genomics, Faculty of Mathematics and Information ScienceWarsaw University of TechnologyWarsawPoland
| | - Szymon Swiezewski
- Laboratory of Seeds Molecular Biology, Institute of Biochemistry and BiophysicsPolish Academy of SciencesWarsawPoland
| |
Collapse
|
26
|
Hong D, Iakoucheva LM. Therapeutic strategies for autism: targeting three levels of the central dogma of molecular biology. Transl Psychiatry 2023; 13:58. [PMID: 36792602 PMCID: PMC9931756 DOI: 10.1038/s41398-023-02356-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/17/2023] Open
Abstract
The past decade has yielded much success in the identification of risk genes for Autism Spectrum Disorder (ASD), with many studies implicating loss-of-function (LoF) mutations within these genes. Despite this, no significant clinical advances have been made so far in the development of therapeutics for ASD. Given the role of LoF mutations in ASD etiology, many of the therapeutics in development are designed to rescue the haploinsufficient effect of genes at the transcriptional, translational, and protein levels. This review will discuss the various therapeutic techniques being developed from each level of the central dogma with examples including: CRISPR activation (CRISPRa) and gene replacement at the DNA level, antisense oligonucleotides (ASOs) at the mRNA level, and small-molecule drugs at the protein level, followed by a review of current delivery methods for these therapeutics. Since central nervous system (CNS) penetrance is of utmost importance for ASD therapeutics, it is especially necessary to evaluate delivery methods that have higher efficiency in crossing the blood-brain barrier (BBB).
Collapse
Affiliation(s)
- Derek Hong
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Lilia M Iakoucheva
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA.
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, USA.
| |
Collapse
|
27
|
Ryczek N, Łyś A, Makałowska I. The Functional Meaning of 5'UTR in Protein-Coding Genes. Int J Mol Sci 2023; 24:2976. [PMID: 36769304 PMCID: PMC9917990 DOI: 10.3390/ijms24032976] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023] Open
Abstract
As it is well known, messenger RNA has many regulatory regions along its sequence length. One of them is the 5' untranslated region (5'UTR), which itself contains many regulatory elements such as upstream ORFs (uORFs), internal ribosome entry sites (IRESs), microRNA binding sites, and structural components involved in the regulation of mRNA stability, pre-mRNA splicing, and translation initiation. Activation of the alternative, more upstream transcription start site leads to an extension of 5'UTR. One of the consequences of 5'UTRs extension may be head-to-head gene overlap. This review describes elements in 5'UTR of protein-coding transcripts and the functional significance of protein-coding genes 5' overlap with implications for transcription, translation, and disease.
Collapse
Affiliation(s)
| | | | - Izabela Makałowska
- Institute of Human Biology and Evolution, Adam Mickiewicz University in Poznań, Uniwersytetu Ponańskiego 6, 61-614 Poznań, Poland
| |
Collapse
|
28
|
Rodríguez-Molina JB, West S, Passmore LA. Knowing when to stop: Transcription termination on protein-coding genes by eukaryotic RNAPII. Mol Cell 2023; 83:404-415. [PMID: 36634677 PMCID: PMC7614299 DOI: 10.1016/j.molcel.2022.12.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/12/2022] [Accepted: 12/20/2022] [Indexed: 01/13/2023]
Abstract
Gene expression is controlled in a dynamic and regulated manner to allow for the consistent and steady expression of some proteins as well as the rapidly changing production of other proteins. Transcription initiation has been a major focus of study because it is highly regulated. However, termination of transcription also plays an important role in controlling gene expression. Transcription termination on protein-coding genes is intimately linked with 3' end cleavage and polyadenylation of transcripts, and it generally results in the production of a mature mRNA that is exported from the nucleus. Termination on many non-coding genes can also result in the production of a mature transcript. Termination is dynamically regulated-premature termination and transcription readthrough occur in response to a number of cellular signals, and these can have varied consequences on gene expression. Here, we review eukaryotic transcription termination by RNA polymerase II (RNAPII), focusing on protein-coding genes.
Collapse
Affiliation(s)
| | - Steven West
- The Living Systems Institute, University of Exeter, Exeter, UK.
| | | |
Collapse
|
29
|
Abraha BW, Marchisio MA. Design of Gene Boolean Gates and Circuits with Convergent Promoters. Methods Mol Biol 2023; 2553:121-154. [PMID: 36227542 DOI: 10.1007/978-1-0716-2617-7_7] [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: 06/16/2023]
Abstract
Gene digital circuits are the subject of many research works due to their various potential applications, from hazard detection to medical diagnostic. Moreover, a remarkable number of techniques, developed in electronics, can be used for the construction of biological digital systems. In our previous works, we showed how to automatize the design and modeling of gene digital circuits whose gates were based on transcription and translation regulation. In this chapter, we illustrate how Boolean gates could be implemented by following a particular architecture, the convergent promoter one, rather diffuse in nature but seldom adopted in Synthetic Biology. Beside gate design, we also explain how to extend our previous modeling approach, based on composable parts and pools of molecules, to quantitatively describe and simulate this particular kind of digital biological devices.
Collapse
Affiliation(s)
- Biruck Woldai Abraha
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
| | | |
Collapse
|
30
|
Miao L, Batty KR, Jackson AN, Pieno HA, Rhoades MW, Kojima S. Genetic and environmental perturbations alter the rhythmic expression pattern of a circadian long non-coding RNA, Per2AS, in mouse liver. F1000Res 2022; 11:1073. [PMID: 36250003 PMCID: PMC9551389 DOI: 10.12688/f1000research.125628.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/26/2022] [Indexed: 11/23/2022] Open
Abstract
Background: Long non-coding RNAs (lncRNAs) play a wide variety of biological roles without encoding a protein. Although the functions of many lncRNAs have been uncovered in recent years, the regulatory mechanism of lncRNA expression is still poorly understood despite that the expression patterns of lncRNAs are much more specific compared to mRNAs. Here, we investigated the rhythmic expression of Per2AS, a novel lncRNA that regulates circadian rhythms. Given that Per2AS expression is antiphasic to Period2 ( Per2), a core circadian clock gene, and transcribed from the antisense strand of Per2, we hypothesized that the rhythmic Per2AS expression is driven either by its own promoter or by the rhythmic Per2 transcription via transcriptional interference. Methods: We leveraged existing circadian RNA-seq datasets and analyzed the expression patterns of Per2AS and Per2 in response to the genetic or environmental disruption of the circadian rhythm in mouse liver. We tested our hypotheses by comparing the changes in the expression patterns of Per2AS and Per2. Conclusions: We found that, in some cases, Per2AS expression is independently controlled by other circadian transcription factors. In other cases, the pattern of expression change is consistent with both transcriptional interference and independent regulation hypotheses. Although additional experiments will be necessary to distinguish these possibilities, findings from this work contribute to a deeper understanding of the mechanism of how the expression of lncRNA is regulated.
Collapse
Affiliation(s)
- Lin Miao
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Kyle R. Batty
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, 24061, USA,Division of Systems Biology, Academy of Integrated Science, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Ayana N. Jackson
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Heather A. Pieno
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Maisy W. Rhoades
- Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Shihoko Kojima
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA,Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA, 24061, USA,Division of Systems Biology, Academy of Integrated Science, Virginia Tech, Blacksburg, VA, 24061, USA,
| |
Collapse
|
31
|
Navigating the Multiverse of Antisense RNAs: The Transcription- and RNA-Dependent Dimension. Noncoding RNA 2022; 8:ncrna8060074. [PMID: 36412909 PMCID: PMC9680235 DOI: 10.3390/ncrna8060074] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/21/2022] [Accepted: 10/23/2022] [Indexed: 12/14/2022] Open
Abstract
Evidence accumulated over the past decades shows that the number of identified antisense transcripts is continuously increasing, promoting them from transcriptional noise to real genes with specific functions. Indeed, recent studies have begun to unravel the complexity of the antisense RNA (asRNA) world, starting from the multidimensional mechanisms that they can exert in physiological and pathological conditions. In this review, we discuss the multiverse of the molecular functions of asRNAs, describing their action through transcription-dependent and RNA-dependent mechanisms. Then, we report the workflow and methodologies to study and functionally characterize single asRNA candidates.
Collapse
|
32
|
Mediouni S, Lyu S, Schader SM, Valente ST. Forging a Functional Cure for HIV: Transcription Regulators and Inhibitors. Viruses 2022; 14:1980. [PMID: 36146786 PMCID: PMC9502519 DOI: 10.3390/v14091980] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 08/28/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Current antiretroviral therapy (ART) increases the survival of HIV-infected individuals, yet it is not curative. The major barrier to finding a definitive cure for HIV is our inability to identify and eliminate long-lived cells containing the dormant provirus, termed viral reservoir. When ART is interrupted, the viral reservoir ensures heterogenous and stochastic HIV viral gene expression, which can reseed infection back to pre-ART levels. While strategies to permanently eradicate the virus have not yet provided significant success, recent work has focused on the management of this residual viral reservoir to effectively limit comorbidities associated with the ongoing viral transcription still observed during suppressive ART, as well as limit the need for daily ART. Our group has been at the forefront of exploring the viability of the block-and-lock remission approach, focused on the long-lasting epigenetic block of viral transcription such that without daily ART, there is no risk of viral rebound, transmission, or progression to AIDS. Numerous studies have reported inhibitors of both viral and host factors required for HIV transcriptional activation. Here, we highlight and review some of the latest HIV transcriptional inhibitor discoveries that may be leveraged for the clinical exploration of block-and-lock and revolutionize the way we treat HIV infections.
Collapse
Affiliation(s)
- Sonia Mediouni
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
| | - Shuang Lyu
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
| | - Susan M. Schader
- Department of Infectious Disease Research, Drug Development Division, Southern Research, 431 Aviation Way, Frederick, MD 21701, USA
| | - Susana T. Valente
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
| |
Collapse
|
33
|
LaFleur TL, Hossain A, Salis HM. Automated model-predictive design of synthetic promoters to control transcriptional profiles in bacteria. Nat Commun 2022; 13:5159. [PMID: 36056029 PMCID: PMC9440211 DOI: 10.1038/s41467-022-32829-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 08/19/2022] [Indexed: 12/22/2022] Open
Abstract
Transcription rates are regulated by the interactions between RNA polymerase, sigma factor, and promoter DNA sequences in bacteria. However, it remains unclear how non-canonical sequence motifs collectively control transcription rates. Here, we combine massively parallel assays, biophysics, and machine learning to develop a 346-parameter model that predicts site-specific transcription initiation rates for any σ70 promoter sequence, validated across 22132 bacterial promoters with diverse sequences. We apply the model to predict genetic context effects, design σ70 promoters with desired transcription rates, and identify undesired promoters inside engineered genetic systems. The model provides a biophysical basis for understanding gene regulation in natural genetic systems and precise transcriptional control for engineering synthetic genetic systems.
Collapse
Affiliation(s)
- Travis L LaFleur
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16801, USA
| | - Ayaan Hossain
- Bioinformatics and Genomics, Pennsylvania State University, University Park, PA, 16801, USA
| | - Howard M Salis
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16801, USA.
- Bioinformatics and Genomics, Pennsylvania State University, University Park, PA, 16801, USA.
- Department of Biological Engineering, Pennsylvania State University, University Park, PA, 16801, USA.
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, 16801, USA.
| |
Collapse
|
34
|
Cheng H, Zhang ES, Shi X, Cao PP, Pan BJ, Si XX, Liu Y, Yang N, Chu Y, Wang XC, Han X, Zhang ZH, Sun YJ. A Novel ATM Antisense Transcript ATM-AS Positively Regulates ATM Expression in Normal and Breast Cancer Cells. Curr Med Sci 2022; 42:681-691. [DOI: 10.1007/s11596-022-2585-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 02/02/2022] [Indexed: 11/03/2022]
Abstract
Abstract
Objective
The ataxia telangiectasia mutated (ATM) gene is a master regulator in cellular DNA damage response. The dysregulation of ATM expression is frequent in breast cancer, and is known to be involved in the carcinogenesis and prognosis of cancer. However, the underlying mechanism remains unclear. The bioinformatic analysis predicted a potential antisense transcript ATM-antisense (AS) from the opposite strand of the ATM gene. The purpose of this study was to identify ATM-AS and investigate the possible effect of ATM-AS on the ATM gene regulation.
Methods
Single strand-specific RT-PCR was performed to verify the predicted antisense transcript ATM-AS within the ATM gene locus. qRT-PCR and Western blotting were used to detect the expression levels of ATM-AS and ATM in normal and breast cancer cell lines as well as in tissue samples. Luciferase reporter gene assays, biological mass spectrometry, ChIP-qPCR and RIP were used to explore the function of ATM-AS in regulating the ATM expression. Immunofluorescence and host-cell reactivation (HCR) assay were performed to evaluate the biological significance of ATM-AS in ATM-mediated DNA damage repair. Breast cancer tissue samples were used for evaluating the correlation of the ATM-AS level with the ATM expression as well as prognosis of the patients.
Results
The ATM-AS significantly upregulated the ATM gene activity by recruiting KAT5 histone acetyltransferase to the gene promoter. The reduced ATM-AS level led to the abnormal downregulation of ATM expression, and impaired the ATM-mediated DNA damage repair in normal breast cells in vitro. The ATM-AS level was positively correlated with the ATM expression in the examined breast cancer tissue samples, and the patient prognosis.
Conclusion
The present study demonstrated that ATM-AS, an antisense transcript located within the ATM gene body, is an essential positive regulator of ATM expression, and functions by mediating the binding of KAT5 to the ATM promoter. These findings uncover the novel mechanism underlying the dysregulation of the ATM gene in breast cancer, and enrich our understanding of how an antisense transcript regulates its host gene.
Collapse
|
35
|
Linden N, Jones RB. Potential multi-modal effects of provirus integration on HIV-1 persistence: lessons from other viruses. Trends Immunol 2022; 43:617-629. [PMID: 35817699 PMCID: PMC9429957 DOI: 10.1016/j.it.2022.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/10/2022] [Accepted: 06/12/2022] [Indexed: 11/29/2022]
Abstract
Despite antiretroviral therapy (ART), HIV-1 persists as proviruses integrated into the genomic DNA of CD4+ T cells. The mechanisms underlying the persistence and clonal expansion of these cells remain incompletely understood. Cases have been described in which proviral integration can alter host gene expression to drive cellular proliferation. Here, we review observations from other genome-integrating human viruses to propose additional putative modalities by which HIV-1 integration may alter cellular function to favor persistence, such as by altering susceptibility to cytotoxicity in virus-expressing cells. We propose that signals implicating such mechanisms may have been masked thus far by the preponderance of defective and/or nonreactivatable HIV-1 proviruses, but could be revealed by focusing on the integration sites of intact proviruses with expression potential.
Collapse
Affiliation(s)
- Noemi Linden
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Immunology and Microbial Pathogenesis Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10021, USA; Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY 10021, USA
| | - R Brad Jones
- Division of Infectious Diseases, Department of Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Immunology and Microbial Pathogenesis Graduate Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10021, USA; Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY 10021, USA.
| |
Collapse
|
36
|
Rodríguez-Molina JB, O'Reilly FJ, Fagarasan H, Sheekey E, Maslen S, Skehel JM, Rappsilber J, Passmore LA. Mpe1 senses the binding of pre-mRNA and controls 3' end processing by CPF. Mol Cell 2022; 82:2490-2504.e12. [PMID: 35584695 PMCID: PMC9380774 DOI: 10.1016/j.molcel.2022.04.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 03/23/2022] [Accepted: 04/18/2022] [Indexed: 12/14/2022]
Abstract
Most eukaryotic messenger RNAs (mRNAs) are processed at their 3' end by the cleavage and polyadenylation specificity factor (CPF/CPSF). CPF mediates the endonucleolytic cleavage of the pre-mRNA and addition of a polyadenosine (poly(A)) tail, which together define the 3' end of the mature transcript. The activation of CPF is highly regulated to maintain the fidelity of RNA processing. Here, using cryo-EM of yeast CPF, we show that the Mpe1 subunit directly contacts the polyadenylation signal sequence in nascent pre-mRNA. The region of Mpe1 that contacts RNA also promotes the activation of CPF endonuclease activity and controls polyadenylation. The Cft2 subunit of CPF antagonizes the RNA-stabilized configuration of Mpe1. In vivo, the depletion or mutation of Mpe1 leads to widespread defects in transcription termination by RNA polymerase II, resulting in transcription interference on neighboring genes. Together, our data suggest that Mpe1 plays a major role in accurate 3' end processing, activating CPF, and ensuring timely transcription termination.
Collapse
Affiliation(s)
| | - Francis J O'Reilly
- Technische Universität Berlin, Chair of Bioanalytics, 10623 Berlin, Germany
| | | | | | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - J Mark Skehel
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Juri Rappsilber
- Technische Universität Berlin, Chair of Bioanalytics, 10623 Berlin, Germany; Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | | |
Collapse
|
37
|
Lensch S, Herschl MH, Ludwig CH, Sinha J, Hinks MM, Mukund A, Fujimori T, Bintu L. Dynamic spreading of chromatin-mediated gene silencing and reactivation between neighboring genes in single cells. eLife 2022; 11:e75115. [PMID: 35678392 PMCID: PMC9183234 DOI: 10.7554/elife.75115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/23/2022] [Indexed: 12/02/2022] Open
Abstract
In mammalian cells genes that are in close proximity can be transcriptionally coupled: silencing or activating one gene can affect its neighbors. Understanding these dynamics is important for natural processes, such as heterochromatin spreading during development and aging, and when designing synthetic gene regulation circuits. Here, we systematically dissect this process in single cells by recruiting and releasing repressive chromatin regulators at dual-gene synthetic reporters, and measuring how fast gene silencing and reactivation spread as a function of intergenic distance and configuration of insulator elements. We find that silencing by KRAB, associated with histone methylation, spreads between two genes within hours, with a time delay that increases with distance. This fast KRAB-mediated spreading is not blocked by the classical cHS4 insulators. Silencing by histone deacetylase HDAC4 of the upstream gene can also facilitate background silencing of the downstream gene by PRC2, but with a days-long delay that does not change with distance. This slower silencing can sometimes be stopped by insulators. Gene reactivation of neighboring genes is also coupled, with strong promoters and insulators determining the order of reactivation. Our data can be described by a model of multi-gene regulation that builds upon previous knowledge of heterochromatin spreading, where both gene silencing and gene reactivation can act at a distance, allowing for coordinated dynamics via chromatin regulator recruitment.
Collapse
Affiliation(s)
- Sarah Lensch
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Michael H Herschl
- University of California, Berkeley—University of California, San Francisco Graduate Program in BioengineeringBerkeleyUnited States
| | - Connor H Ludwig
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Joydeb Sinha
- Department of Chemical and Systems Biology, Stanford UniversityStanfordUnited States
| | - Michaela M Hinks
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Adi Mukund
- Biophysics Program, Stanford UniversityStanfordUnited States
| | - Taihei Fujimori
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Lacramioara Bintu
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| |
Collapse
|
38
|
Villa T, Porrua O. Pervasive transcription: a controlled risk. FEBS J 2022. [PMID: 35587776 DOI: 10.1111/febs.16530] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022]
Abstract
Transcriptome-wide interrogation of eukaryotic genomes has unveiled the pervasive nature of RNA polymerase II transcription. Virtually, any DNA region with an accessible chromatin structure can be transcribed, resulting in a mass production of noncoding RNAs (ncRNAs) with the potential of interfering with gene expression programs. Budding yeast has proved to be a powerful model organism to understand the mechanisms at play to control pervasive transcription and overcome the risks of hazardous disruption of cellular functions. In this review, we focus on the actors and strategies yeasts employ to govern ncRNA production, and we discuss recent findings highlighting the dangers of losing control over pervasive transcription.
Collapse
Affiliation(s)
- Tommaso Villa
- Institut Jacques Monod CNRS, Université de Paris Cité France
| | - Odil Porrua
- Institut Jacques Monod CNRS, Université de Paris Cité France
| |
Collapse
|
39
|
Núñez-Martínez HN, Recillas-Targa F. Emerging Functions of lncRNA Loci beyond the Transcript Itself. Int J Mol Sci 2022; 23:ijms23116258. [PMID: 35682937 PMCID: PMC9181104 DOI: 10.3390/ijms23116258] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/14/2022] [Accepted: 05/30/2022] [Indexed: 02/04/2023] Open
Abstract
Thousands of long noncoding RNAs (lncRNAs) are actively transcribed in mammalian genomes. This class of RNAs has important regulatory functions in a broad range of cellular processes and diseases. Numerous lncRNAs have been demonstrated to mediate gene regulation through RNA-based mechanisms. Simultaneously, non-functional lncRNA transcripts derived from the activity of lncRNA loci have been identified, which underpin the notion that a considerable fraction of lncRNA loci exert regulatory functions through mechanisms associated with the production or the activity of lncRNA loci beyond the synthesized transcripts. We particularly distinguish two main RNA-independent components associated with regulatory effects; the act of transcription and the activity of DNA regulatory elements. We describe the experimental approaches to distinguish and understand the functional mechanisms derived from lncRNA loci. These scenarios reveal emerging mechanisms important to understanding the lncRNA implications in genome biology.
Collapse
|
40
|
Morgan M, Shiekhattar R, Shilatifard A, Lauberth SM. It's a DoG-eat-DoG world-altered transcriptional mechanisms drive downstream-of-gene (DoG) transcript production. Mol Cell 2022; 82:1981-1991. [PMID: 35487209 PMCID: PMC9208299 DOI: 10.1016/j.molcel.2022.04.008] [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: 01/10/2022] [Revised: 02/24/2022] [Accepted: 04/04/2022] [Indexed: 10/18/2022]
Abstract
The past decade has revolutionized our understanding of regulatory noncoding RNAs (ncRNAs). Among the most recently identified ncRNAs are downstream-of-gene (DoG)-containing transcripts that are produced by widespread transcriptional readthrough. The discovery of DoGs has set the stage for future studies to address many unanswered questions regarding the mechanisms that promote readthrough transcription, RNA processing, and the cellular functions of the unique transcripts. In this review, we summarize current findings regarding the biogenesis, function, and mechanisms regulating this exciting new class of RNA molecules.
Collapse
Affiliation(s)
- Marc Morgan
- Simpson Querrey Institute for Epigenetics and Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Ramin Shiekhattar
- Department of Human Genetics, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ali Shilatifard
- Simpson Querrey Institute for Epigenetics and Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Shannon M Lauberth
- Simpson Querrey Institute for Epigenetics and Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
| |
Collapse
|
41
|
Falgenhauer E, Mückl A, Schwarz-Schilling M, Simmel FC. Transcriptional Interference in Toehold Switch-Based RNA Circuits. ACS Synth Biol 2022; 11:1735-1745. [PMID: 35412304 DOI: 10.1021/acssynbio.1c00486] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Gene regulation based on regulatory RNA is an important mechanism in cells and is increasingly used for regulatory circuits in synthetic biology. Toehold switches are rationally designed post-transcriptional riboregulators placed in the 5' untranslated region of mRNA molecules. In the inactive state of a toehold switch, the ribosome-binding site is inaccessible to the ribosome. In the presence of a trigger RNA molecule, protein production is turned on. Using antisense RNA against trigger molecules (antitrigger RNA), gene expression can also be switched off again. We here study the utility of antisense transcription in this context, which enables a particularly compact circuit design. Our circuits utilize two inducible promoters that separately regulate trigger and antitrigger transcription, whereas their cognate toehold switch, regulating the expression of a reporter protein, is transcribed from a constitutive promoter. We explore various design options for the arrangement of the promoters and demonstrate that the resulting dynamic behavior is influenced by transcriptional interference (TI) effects depending on the promoter distance. Our experimental results are consistent with previous findings that enhanced local RNA polymerase concentrations due to active promoters in close proximity lead to an increase in transcriptional activity of the strongest promoter in the circuits. We observed that the range of this effect is larger when the participating promoters are stronger. Based on this insight, we combined two promoter arrangements for the realization of a genetic circuit comprised of two toehold switches, two triggers, and two antitriggers that function as a two-input two-output logic gate.
Collapse
Affiliation(s)
- Elisabeth Falgenhauer
- Physics Department - E14 and ZNN/WSI, TU Munich, Am Coulombwall 4a, 85748 Garching, Germany
| | - Andrea Mückl
- Physics Department - E14 and ZNN/WSI, TU Munich, Am Coulombwall 4a, 85748 Garching, Germany
| | | | - Friedrich C. Simmel
- Physics Department - E14 and ZNN/WSI, TU Munich, Am Coulombwall 4a, 85748 Garching, Germany
| |
Collapse
|
42
|
Hocq R, Jagtap S, Boutard M, Tolonen AC, Duval L, Pirayre A, Lopes Ferreira N, Wasels F. Genome-Wide TSS Distribution in Three Related Clostridia with Normalized Capp-Switch Sequencing. Microbiol Spectr 2022; 10:e0228821. [PMID: 35412381 PMCID: PMC9045289 DOI: 10.1128/spectrum.02288-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/22/2022] [Indexed: 11/20/2022] Open
Abstract
Transcription initiation is a tightly regulated process that is crucial for many aspects of prokaryotic physiology. High-throughput transcription start site (TSS) mapping can shed light on global and local regulation of transcription initiation, which in turn may help us understand and predict microbial behavior. In this study, we used Capp-Switch sequencing to determine the TSS positions in the genomes of three model solventogenic clostridia: Clostridium acetobutylicum ATCC 824, C. beijerinckii DSM 6423, and C. beijerinckii NCIMB 8052. We first refined the approach by implementing a normalization pipeline accounting for gene expression, yielding a total of 12,114 mapped TSSs across the species. We further compared the distributions of these sites in the three strains. Results indicated similar distribution patterns at the genome scale, but also some sharp differences, such as for the butyryl-CoA synthesis operon, particularly when comparing C. acetobutylicum to the C. beijerinckii strains. Lastly, we found that promoter structure is generally poorly conserved between C. acetobutylicum and C. beijerinckii. A few conserved promoters across species are discussed, showing interesting examples of how TSS determination and comparison can improve our understanding of gene expression regulation at the transcript level. IMPORTANCE Solventogenic clostridia have been employed in industry for more than a century, initially being used in the acetone-butanol-ethanol (ABE) fermentation process for acetone and butanol production. Interest in these bacteria has recently increased in the context of green chemistry and sustainable development. However, our current understanding of their genomes and physiology limits their optimal use as industrial solvent production platforms. The gene regulatory mechanisms of solventogenesis are still only partly understood, impeding efforts to increase rates and yields. Genome-wide mapping of transcription start sites (TSSs) for three model solventogenic Clostridium strains is an important step toward understanding mechanisms of gene regulation in these industrially important bacteria.
Collapse
Affiliation(s)
- Rémi Hocq
- IFP Energies Nouvelles, Rueil-Malmaison, France
| | | | - Magali Boutard
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d’Evry, Université Paris-Saclay, Evry, France
| | - Andrew C. Tolonen
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d’Evry, Université Paris-Saclay, Evry, France
| | | | | | | | | |
Collapse
|
43
|
Lee S, Fu F, Liao CJ, Mewa DB, Adeyanju A, Ejeta G, Lisch D, Mengiste T. Broad-spectrum fungal resistance in sorghum is conferred through the complex regulation of an immune receptor gene embedded in a natural antisense transcript. THE PLANT CELL 2022; 34:1641-1665. [PMID: 35018449 PMCID: PMC9048912 DOI: 10.1093/plcell/koab305] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/09/2021] [Indexed: 06/12/2023]
Abstract
Sorghum (Sorghum bicolor), the fifth most widely grown cereal crop globally, provides food security for millions of people. Anthracnose caused by the fungus Colletotrichum sublineola is a major disease of sorghum worldwide. We discovered a major fungal resistance locus in sorghum composed of the nucleotide-binding leucine-rich repeat receptor gene ANTHRACNOSE RESISTANCE GENE1 (ARG1) that is completely nested in an intron of a cis-natural antisense transcript (NAT) gene designated CARRIER OF ARG1 (CARG). Susceptible genotypes express CARG and two alternatively spliced ARG1 transcripts encoding truncated proteins lacking the leucine-rich repeat domains. In resistant genotypes, elevated expression of an intact allele of ARG1, attributed to the loss of CARG transcription and the presence of miniature inverted-repeat transposable element sequences, resulted in broad-spectrum resistance to fungal pathogens with distinct virulence strategies. Increased ARG1 expression in resistant genotypes is also associated with higher histone H3K4 and H3K36 methylation. In susceptible genotypes, lower ARG1 expression is associated with reduced H3K4 and H3K36 methylation and increased expression of NATs of CARG. The repressive chromatin state associated with H3K9me2 is low in CARG-expressing genotypes within the CARG exon and higher in genotypes with low CARG expression. Thus, ARG1 is regulated by multiple mechanisms and confers broad-spectrum, strong resistance to fungal pathogens.
Collapse
Affiliation(s)
| | | | - Chao-Jan Liao
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Demeke B Mewa
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | - Adedayo Adeyanju
- Department of Agronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Gebisa Ejeta
- Department of Agronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Damon Lisch
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907, USA
| | | |
Collapse
|
44
|
Nissani N, Ulitsky I. Unique features of transcription termination and initiation at closely spaced tandem human genes. Mol Syst Biol 2022; 18:e10682. [PMID: 35362230 PMCID: PMC8972054 DOI: 10.15252/msb.202110682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 11/09/2022] Open
Abstract
The synthesis of RNA polymerase II (Pol2) products, which include messenger RNAs or long noncoding RNAs, culminates in transcription termination. How the transcriptional termination of a gene impacts the activity of promoters found immediately downstream of it, and which can be subject to potential transcriptional interference, remains largely unknown. We examined in an unbiased manner the features of the intergenic regions between pairs of 'tandem genes'-closely spaced (< 2 kb) human genes found on the same strand. Intergenic regions separating tandem genes are enriched with guanines and are characterized by binding of several proteins, including AGO1 and AGO2 of the RNA interference pathway. Additionally, we found that Pol2 is particularly enriched in this region, and it is lost upon perturbations affecting splicing or transcriptional elongation. Perturbations of genes involved in Pol2 pausing and R loop biology preferentially affect expression of downstream genes in tandem gene pairs. Overall, we find that features associated with Pol2 pausing and accumulation rather than those associated with avoidance of transcriptional interference are the predominant driving force shaping short tandem intergenic regions.
Collapse
Affiliation(s)
- Noa Nissani
- Departments of Biological Regulation and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| | - Igor Ulitsky
- Departments of Biological Regulation and Molecular NeuroscienceWeizmann Institute of ScienceRehovotIsrael
| |
Collapse
|
45
|
Epimutation in inherited metabolic disorders: the influence of aberrant transcription in adjacent genes. Hum Genet 2022; 141:1309-1325. [PMID: 35190856 DOI: 10.1007/s00439-021-02414-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 12/08/2021] [Indexed: 12/12/2022]
Abstract
Epigenetic diseases can be produced by a stable alteration, called an epimutation, in DNA methylation, in which epigenome alterations are directly involved in the underlying molecular mechanisms of the disease. This review focuses on the epigenetics of two inherited metabolic diseases, epi-cblC, an inherited metabolic disorder of cobalamin (vitamin B12) metabolism, and alpha-thalassemia type α-ZF, an inherited disorder of α2-globin synthesis, with a particular interest in the role of aberrant antisense transcription of flanking genes in the generation of epimutations in CpG islands of gene promoters. In both disorders, the epimutation is triggered by an aberrant antisense transcription through the promoter, which produces an H3K36me3 histone mark involved in the recruitment of DNA methyltransferases. It results from diverse genetic alterations. In alpha-thalassemia type α-ZF, a deletion removes HBA1 and HBQ1 genes and juxtaposes the antisense LUC7L gene to the HBA2 gene. In epi-cblC, the epimutation in the MMACHC promoter is produced by mutations in the antisense flanking gene PRDX1, which induces a prolonged antisense transcription through the MMACHC promoter. The presence of the epimutation in sperm, its transgenerational inheritance via the mutated PRDX1, and the high expression of PRDX1 in spermatogonia but its nearly undetectable transcription in spermatids and spermatocytes, suggest that the epimutation could be maintained during germline reprogramming and despite removal of aberrant transcription. The epivariation seen in the MMACHC promoter (0.95 × 10-3) is highly frequent compared to epivariations affecting other genes of the Online Catalog of Human Genes and Genetic Disorders in an epigenome-wide dataset of 23,116 individuals. This and the comparison of epigrams of two monozygotic twins suggest that the aberrant transcription could also be influenced by post-zygotic environmental exposures.
Collapse
|
46
|
Cain JA, Montibus B, Oakey RJ. Intragenic CpG Islands and Their Impact on Gene Regulation. Front Cell Dev Biol 2022; 10:832348. [PMID: 35223855 PMCID: PMC8873577 DOI: 10.3389/fcell.2022.832348] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/20/2022] [Indexed: 11/16/2022] Open
Abstract
The mammalian genome is depleted in CG dinucleotides, except at protected regions where they cluster as CpG islands (CGIs). CGIs are gene regulatory hubs and serve as transcription initiation sites and are as expected, associated with gene promoters. Advances in genomic annotations demonstrate that a quarter of CGIs are found within genes. Such intragenic regions are repressive environments, so it is surprising that CGIs reside here and even more surprising that some resist repression and are transcriptionally active within a gene. Hence, intragenic CGI positioning within genes is not arbitrary and is instead, selected for. As a wealth of recent studies demonstrate, intragenic CGIs are embedded within genes and consequently, influence ‘host’ gene mRNA isoform length and expand transcriptome diversity.
Collapse
|
47
|
Nojima T, Proudfoot NJ. Mechanisms of lncRNA biogenesis as revealed by nascent transcriptomics. Nat Rev Mol Cell Biol 2022; 23:389-406. [DOI: 10.1038/s41580-021-00447-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2021] [Indexed: 12/14/2022]
|
48
|
James S, Jain V. A positive Selection Escherichia Coli Recombinant Protein Expression Vector for One-Step Cloning. Front Bioeng Biotechnol 2022; 9:776828. [PMID: 35047486 PMCID: PMC8761972 DOI: 10.3389/fbioe.2021.776828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/08/2021] [Indexed: 11/13/2022] Open
Abstract
We introduce OLIVAR ( O rientation se L ection of I nsert in V ector through A ntisense R eporter) as a novel selection strategy for the insertion of protein-coding genes into vector backbones. As a proof-of-concept, we have engineered a plasmid vector, pGRASS ( G reen fluorescent protein R eporter from A ntisense promoter-based S creening S ystem), for gene cloning in E. coli. With pGRASS, positive clones can be effortlessly distinguished from negative clones after blunt-end cloning. The vector not only screens clones with an insert but also for its correct orientation. The design further allows for the expression of recombinant protein from the T7 promoter in an appropriate host bacterium. With this vector, we are able to reduce the entire cloning workflow into a single step involving a 2-h reaction at room temperature. We believe that our cloning-cum-screening system presented here is extremely cost-effective and straightforward and can be applied to other vector systems and domains such as phage display and library construction.
Collapse
Affiliation(s)
- Shinto James
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India
| | - Vikas Jain
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Bhopal, India
| |
Collapse
|
49
|
Fonseca ÉL, Vicente AC. Integron Functionality and Genome Innovation: An Update on the Subtle and Smart Strategy of Integrase and Gene Cassette Expression Regulation. Microorganisms 2022; 10:microorganisms10020224. [PMID: 35208680 PMCID: PMC8876359 DOI: 10.3390/microorganisms10020224] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 12/22/2022] Open
Abstract
Integrons are considered hot spots for bacterial evolution, since these platforms allow one-step genomic innovation by capturing and expressing genes that provide advantageous novelties, such as antibiotic resistance. The acquisition and shuffling of gene cassettes featured by integrons enable the population to rapidly respond to changing selective pressures. However, in order to avoid deleterious effects and fitness burden, the integron activity must be tightly controlled, which happens in an elegant and elaborate fashion, as discussed in detail in the present review. Here, we aimed to provide an up-to-date overview of the complex regulatory networks that permeate the expression and functionality of integrons at both transcriptional and translational levels. It was possible to compile strong shreds of evidence clearly proving that these versatile platforms include functions other than acquiring and expressing gene cassettes. The well-balanced mechanism of integron expression is intricately related with environmental signals, host cell physiology, fitness, and survival, ultimately leading to adaptation on the demand.
Collapse
|
50
|
Chauhan V, Bahrudeen MNM, Palma CSD, Baptista ISC, Almeida BLB, Dash S, Kandavalli V, Ribeiro AS. Analytical kinetic model of native tandem promoters in E. coli. PLoS Comput Biol 2022; 18:e1009824. [PMID: 35100257 PMCID: PMC8830795 DOI: 10.1371/journal.pcbi.1009824] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/10/2022] [Accepted: 01/11/2022] [Indexed: 02/04/2023] Open
Abstract
Closely spaced promoters in tandem formation are abundant in bacteria. We investigated the evolutionary conservation, biological functions, and the RNA and single-cell protein expression of genes regulated by tandem promoters in E. coli. We also studied the sequence (distance between transcription start sites ‘dTSS’, pause sequences, and distances from oriC) and potential influence of the input transcription factors of these promoters. From this, we propose an analytical model of gene expression based on measured expression dynamics, where RNAP-promoter occupancy times and dTSS are the key regulators of transcription interference due to TSS occlusion by RNAP at one of the promoters (when dTSS ≤ 35 bp) and RNAP occupancy of the downstream promoter (when dTSS > 35 bp). Occlusion and downstream promoter occupancy are modeled as linear functions of occupancy time, while the influence of dTSS is implemented by a continuous step function, fit to in vivo data on mean single-cell protein numbers of 30 natural genes controlled by tandem promoters. The best-fitting step is at 35 bp, matching the length of DNA occupied by RNAP in the open complex formation. This model accurately predicts the squared coefficient of variation and skewness of the natural single-cell protein numbers as a function of dTSS. Additional predictions suggest that promoters in tandem formation can cover a wide range of transcription dynamics within realistic intervals of parameter values. By accurately capturing the dynamics of these promoters, this model can be helpful to predict the dynamics of new promoters and contribute to the expansion of the repertoire of expression dynamics available to synthetic genetic constructs. Tandem promoters are common in nature, but investigations on their dynamics have so far largely relied on synthetic constructs. Thus, their regulation and potentially unique dynamics remain unexplored. We first performed a comprehensive exploration of the conservation of genes regulated by these promoters in E. coli and the properties of their input transcription factors. We then measured protein and RNA levels expressed by 30 Escherichia coli tandem promoters, to establish an analytical model of the expression dynamics of genes controlled by such promoters. We show that start site occlusion and downstream RNAP occupancy can be realistically captured by a model with RNAP binding affinity, the time length of open complex formation, and the nucleotide distance between transcription start sites. This study contributes to a better understanding of the unique dynamics tandem promoters can bring to the dynamics of gene networks and will assist in their use in synthetic genetic circuits.
Collapse
Affiliation(s)
- Vatsala Chauhan
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Finland
| | - Mohamed N. M. Bahrudeen
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Finland
| | - Cristina S. D. Palma
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Finland
| | - Ines S. C. Baptista
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Finland
| | - Bilena L. B. Almeida
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Finland
| | - Suchintak Dash
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Finland
| | - Vinodh Kandavalli
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Andre S. Ribeiro
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Finland
- * E-mail:
| |
Collapse
|