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Leydon AR, Downing B, Sanchez JS, Loll-Krippleber R, Belliveau NM, Rodriguez-Mias RA, Bauer A, Watson IJ, Bae L, Villén J, Brown GW, Nemhauser JL. A conserved function of corepressors is to nucleate assembly of the transcriptional preinitiation complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587599. [PMID: 38617365 PMCID: PMC11014602 DOI: 10.1101/2024.04.01.587599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
The plant corepressor TPL is recruited to diverse chromatin contexts, yet its mechanism of repression remains unclear. Previously, we have leveraged the fact that TPL retains its function in a synthetic transcriptional circuit in the yeast model Saccharomyces cerevisiae to localize repressive function to two distinct domains. Here, we employed two unbiased whole genome approaches to map the physical and genetic interactions of TPL at a repressed locus. We identified SPT4, SPT5 and SPT6 as necessary for repression with the SPT4 subunit acting as a bridge connecting TPL to SPT5 and SPT6. We also discovered the association of multiple additional constituents of the transcriptional preinitiation complex at TPL-repressed promoters, specifically those involved in early transcription initiation events. These findings were validated in yeast and plants through multiple assays, including a novel method to analyze conditional loss of function of essential genes in plants. Our findings support a model where TPL nucleates preassembly of the transcription activation machinery to facilitate rapid onset of transcription once repression is relieved.
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Affiliation(s)
| | - Benjamin Downing
- Department of Biology, University of Washington, Seattle, 98195, USA
| | | | | | | | | | - Andrew Bauer
- Department of Biology, University of Washington, Seattle, 98195, USA
| | | | - Lena Bae
- Department of Biology, University of Washington, Seattle, 98195, USA
| | - Judit Villén
- Department of Genome Sciences, University of Washington, Seattle, 98195, USA
| | - Grant W. Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, Ontario, CA
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2
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Xi S, Nguyen T, Murray S, Lorenz P, Mellor J. Size fractionated NET-Seq reveals a conserved architecture of transcription units around yeast genes. Yeast 2024; 41:222-241. [PMID: 38433440 DOI: 10.1002/yea.3931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 03/05/2024] Open
Abstract
Genomes from yeast to humans are subject to pervasive transcription. A single round of pervasive transcription is sufficient to alter local chromatin conformation, nucleosome dynamics and gene expression, but is hard to distinguish from background signals. Size fractionated native elongating transcript sequencing (sfNET-Seq) was developed to precisely map nascent transcripts independent of expression levels. RNAPII-associated nascent transcripts are fractionation into different size ranges before library construction. When anchored to the transcription start sites (TSS) of annotated genes, the combined pattern of the output metagenes gives the expected reference pattern. Bioinformatic pattern matching to the reference pattern identified 9542 transcription units in Saccharomyces cerevisiae, of which 47% are coding and 53% are noncoding. In total, 3113 (33%) are unannotated noncoding transcription units. Anchoring all transcription units to the TSS or polyadenylation site (PAS) of annotated genes reveals distinctive architectures of linked pairs of divergent transcripts approximately 200nt apart. The Reb1 transcription factor is enriched 30nt downstream of the PAS only when an upstream (TSS -60nt with respect to PAS) noncoding transcription unit co-occurs with a downstream (TSS +150nt) coding transcription unit and acts to limit levels of upstream antisense transcripts. The potential for extensive transcriptional interference is evident from low abundance unannotated transcription units with variable TSS (median -240nt) initiating within a 500nt window upstream of, and transcribing over, the promoters of protein-coding genes. This study confirms a highly interleaved yeast genome with different types of transcription units altering the chromatin landscape in distinctive ways, with the potential to exert extensive regulatory control.
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Affiliation(s)
- Shidong Xi
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Tania Nguyen
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Struan Murray
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Phil Lorenz
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Jane Mellor
- Department of Biochemistry, University of Oxford, Oxford, UK
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3
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Tonsager AJ, Zukowski A, Radebaugh CA, Weirich A, Stargell LA, Ramachandran S. THE HISTONE CHAPERONE SPN1 PRESERVES SUBNUCLEOSOMAL STRUCTURES AT PROMOTERS AND NUCLEOSOME POSITIONING IN OPEN READING FRAMES. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.14.585010. [PMID: 38559248 PMCID: PMC10979989 DOI: 10.1101/2024.03.14.585010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Spn1 is a multifunctional histone chaperone essential for life in eukaryotes. While previous work has elucidated regions of the protein important for its many interactions, it is unknown how these domains contribute to the maintenance of chromatin structure. Here, we employ digestion by micrococcal nuclease followed by single-stranded library preparation and sequencing (MNase-SSP) to characterize chromatin structure in yeast expressing wild-type or mutants of Spn1. We mapped nucleosome and subnucleosomal protections genome-wide, and surprisingly, we observed a genome-wide loss of subnucleosomal protection over nucleosome-depleted regions (NDRs) in the Spn1-K192N-containing strain, indicating critical functions of Spn1 in maintaining normal chromatin architecture in promoter regions. Additionally, alterations in nucleosome and hexasome positioning were observed in markedly different mutant Spn1 strains, demonstrating that multiple functions of Spn1 are required to maintain proper chromatin structure in open reading frames, particularly at higher expressed and longer genes. Taken together, our results reveal a previously unknown role of Spn1 in the maintenance of NDR architecture and deepen our understanding of Spn1-dependent chromatin maintenance over transcribed regions.
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Affiliation(s)
- Andrew J. Tonsager
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1870, USA
| | | | - Catherine A. Radebaugh
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1870, USA
| | | | - Laurie A. Stargell
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523-1870, USA
| | - Srinivas Ramachandran
- Department of Biochemistry and Molecular Genetics
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, U80045, USA
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4
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Sekine SI, Ehara H, Kujirai T, Kurumizaka H. Structural perspectives on transcription in chromatin. Trends Cell Biol 2024; 34:211-224. [PMID: 37596139 DOI: 10.1016/j.tcb.2023.07.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/20/2023]
Abstract
In eukaryotes, all genetic processes take place in the cell nucleus, where DNA is packaged as chromatin in 'beads-on-a-string' nucleosome arrays. RNA polymerase II (RNAPII) transcribes protein-coding and many non-coding genes in this chromatin environment. RNAPII elongates RNA while passing through multiple nucleosomes and maintaining the integrity of the chromatin structure. Recent structural studies have shed light on the detailed mechanisms of this process, including how transcribing RNAPII progresses through a nucleosome and reassembles it afterwards, and how transcription elongation factors, chromatin remodelers, and histone chaperones participate in these processes. Other studies have also illuminated the crucial role of nucleosomes in preinitiation complex assembly and transcription initiation. In this review we outline these advances and discuss future perspectives.
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Affiliation(s)
- Shun-Ichi Sekine
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan.
| | - Haruhiko Ehara
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Tomoya Kujirai
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan; Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hitoshi Kurumizaka
- Laboratory for Transcription Structural Biology, RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan; Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
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5
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Schofield JA, Hahn S. Broad compatibility between yeast UAS elements and core promoters and identification of promoter elements that determine cofactor specificity. Cell Rep 2023; 42:112387. [PMID: 37058407 PMCID: PMC10567116 DOI: 10.1016/j.celrep.2023.112387] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/30/2023] [Accepted: 03/28/2023] [Indexed: 04/15/2023] Open
Abstract
Three classes of yeast protein-coding genes are distinguished by their dependence on the transcription cofactors TFIID, SAGA, and Mediator (MED) Tail, but whether this dependence is determined by the core promoter, upstream activating sequences (UASs), or other gene features is unclear. Also unclear is whether UASs can broadly activate transcription from the different promoter classes. Here, we measure transcription and cofactor specificity for thousands of UAS-core promoter combinations and find that most UASs broadly activate promoters regardless of regulatory class, while few display strong promoter specificity. However, matching UASs and promoters from the same gene class is generally important for optimal expression. We find that sensitivity to rapid depletion of MED Tail or SAGA is dependent on the identity of both UAS and core promoter, while dependence on TFIID localizes to only the promoter. Finally, our results suggest the role of TATA and TATA-like promoter sequences in MED Tail function.
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Affiliation(s)
- Jeremy A Schofield
- Basic Sciences Division, Fred Hutchinson Cancer Center, 1100 Fairview Avenue N, Seattle, WA 98105, USA
| | - Steven Hahn
- Basic Sciences Division, Fred Hutchinson Cancer Center, 1100 Fairview Avenue N, Seattle, WA 98105, USA.
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6
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Gregersen LH, Mitter R, Svejstrup JQ. Elongation factor-specific capture of RNA polymerase II complexes. CELL REPORTS METHODS 2022; 2:100368. [PMID: 36590686 PMCID: PMC9795356 DOI: 10.1016/j.crmeth.2022.100368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/25/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022]
Abstract
Transcription of protein-coding genes is regulated by dynamic association of co-factors with RNA polymerase II (RNAPII). The function of these factors and their relationship with RNAPII is often poorly understood. Here, we present an approach for elongation-factor-specific mNET capture (ELCAP) of RNAPII complexes for sequencing and mass spectrometry analysis aimed at investigating the function of such RNAPII regulatory proteins. As proof of principle, we apply ELCAP to the RNAPII-associated proteins SCAF4 and SCAF8, which share an essential role as mRNA anti-terminators but have individual roles at the 3' end of genes. Mass spectrometry analysis shows that both SCAF4 and SCAF8 are part of RNAPII elongation complexes containing 3' end processing factors but depleted of splicing components. Importantly, the ELCAP sequencing (ELCAP-seq) profiles of SCAF4- and SCAF8-RNAPII complexes nicely reflect their function as mRNA-anti-terminators and their competing functions at the end of genes, where they prevent or promote transcriptional readthrough.
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Affiliation(s)
- Lea H. Gregersen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Richard Mitter
- Bioinformatics and Biostatistics, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jesper Q. Svejstrup
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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7
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Ehara H, Kujirai T, Shirouzu M, Kurumizaka H, Sekine SI. Structural basis of nucleosome disassembly and reassembly by RNAPII elongation complex with FACT. Science 2022; 377:eabp9466. [PMID: 35981082 DOI: 10.1126/science.abp9466] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
During gene transcription, RNA polymerase II (RNAPII) traverses nucleosomes in chromatin, but its mechanism has remained elusive. Using cryo-electron microscopy, we obtained structures of the RNAPII elongation complex (EC) passing through a nucleosome, in the presence of transcription elongation factors Spt6, Spn1, Elf1, Spt4/5, and Paf1C and the histone chaperone FACT. The structures show snapshots of EC progression on DNA, mediating downstream nucleosome disassembly followed by its reassembly upstream of the EC, facilitated by FACT. FACT dynamically adapts to successively occurring subnucleosome intermediates, forming an interface with the EC. Spt6, Spt4/5, and Paf1C form a "cradle" at the EC DNA-exit site, and support the upstream nucleosome reassembly. These structures explain the mechanism by which the EC traverses nucleosomes while maintaining the chromatin structure and epigenetic information.
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Affiliation(s)
- Haruhiko Ehara
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Tomoya Kujirai
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan.,Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Mikako Shirouzu
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Hitoshi Kurumizaka
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan.,Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Shun-Ichi Sekine
- RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
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8
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Song A, Chen FX. The pleiotropic roles of SPT5 in transcription. Transcription 2022; 13:53-69. [PMID: 35876486 PMCID: PMC9467590 DOI: 10.1080/21541264.2022.2103366] [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] [Indexed: 10/25/2022] Open
Abstract
Initially discovered by genetic screens in budding yeast, SPT5 and its partner SPT4 form a stable complex known as DSIF in metazoa, which plays pleiotropic roles in multiple steps of transcription. SPT5 is the most conserved transcription elongation factor, being found in all three domains of life; however, its structure has evolved to include new domains and associated posttranslational modifications. These gained features have expanded transcriptional functions of SPT5, likely to meet the demand for increasingly complex regulation of transcription in higher organisms. This review discusses the pleiotropic roles of SPT5 in transcription, including RNA polymerase II (Pol II) stabilization, enhancer activation, Pol II pausing and its release, elongation, and termination, with a focus on the most recent progress of SPT5 functions in regulating metazoan transcription.
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Affiliation(s)
- Aixia Song
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
| | - Fei Xavier Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, Province 200032, China
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9
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Kong S, Lu Y, Tan S, Li R, Gao Y, Li K, Zhang Y. Nucleosome-Omics: A Perspective on the Epigenetic Code and 3D Genome Landscape. Genes (Basel) 2022; 13:genes13071114. [PMID: 35885897 PMCID: PMC9323251 DOI: 10.3390/genes13071114] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/14/2022] [Accepted: 06/17/2022] [Indexed: 12/04/2022] Open
Abstract
Genetic information is loaded on chromatin, which involves DNA sequence arrangement and the epigenetic landscape. The epigenetic information including DNA methylation, nucleosome positioning, histone modification, 3D chromatin conformation, and so on, has a crucial impact on gene transcriptional regulation. Out of them, nucleosomes, as basal chromatin structural units, play an important central role in epigenetic code. With the discovery of nucleosomes, various nucleosome-level technologies have been developed and applied, pushing epigenetics to a new climax. As the underlying methodology, next-generation sequencing technology has emerged and allowed scientists to understand the epigenetic landscape at a genome-wide level. Combining with NGS, nucleosome-omics (or nucleosomics) provides a fresh perspective on the epigenetic code and 3D genome landscape. Here, we summarized and discussed research progress in technology development and application of nucleosome-omics. We foresee the future directions of epigenetic development at the nucleosome level.
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10
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Filipovski M, Soffers JHM, Vos SM, Farnung L. Structural basis of nucleosome retention during transcription elongation. Science 2022; 376:1313-1316. [PMID: 35709268 DOI: 10.1126/science.abo3851] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In eukaryotes, RNA polymerase (Pol) II transcribes chromatin and must move past nucleosomes, often resulting in nucleosome displacement. How Pol II unwraps the DNA from nucleosomes to allow transcription and how DNA rewraps to retain nucleosomes has been unclear. Here, we report the 3.0-angstrom cryo-electron microscopy structure of a mammalian Pol II-DSIF-SPT6-PAF1c-TFIIS-nucleosome complex stalled 54 base pairs within the nucleosome. The structure provides a mechanistic basis for nucleosome retention during transcription elongation where upstream DNA emerging from the Pol II cleft has rewrapped the proximal side of the nucleosome. The structure uncovers a direct role for Pol II and transcription elongation factors in nucleosome retention and explains how nucleosomes are retained to prevent the disruption of chromatin structure across actively transcribed genes.
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Affiliation(s)
- Martin Filipovski
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Jelly H M Soffers
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Seychelle M Vos
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Lucas Farnung
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
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11
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Cheon Y, Han S, Kim T, Hwang D, Lee D. The chromatin remodeler Ino80 mediates RNAPII pausing site determination. Genome Biol 2021; 22:294. [PMID: 34663418 PMCID: PMC8524862 DOI: 10.1186/s13059-021-02500-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/15/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Promoter-proximal pausing of RNA polymerase II (RNAPII) is a critical step for the precise regulation of gene expression. Despite the apparent close relationship between promoter-proximal pausing and nucleosome, the role of chromatin remodeler governing this step has mainly remained elusive. RESULTS Here, we report highly confined RNAPII enrichments downstream of the transcriptional start site in Saccharomyces cerevisiae using PRO-seq experiments. This non-uniform distribution of RNAPII exhibits both similar and different characteristics with promoter-proximal pausing in Schizosaccharomyces pombe and metazoans. Interestingly, we find that Ino80p knockdown causes a significant upstream transition of promoter-proximal RNAPII for a subset of genes, relocating RNAPII from the main pausing site to the alternative pausing site. The proper positioning of RNAPII is largely dependent on nucleosome context. We reveal that the alternative pausing site is closely associated with the + 1 nucleosome, and nucleosome architecture around the main pausing site of these genes is highly phased. In addition, Ino80p knockdown results in an increase in fuzziness and a decrease in stability of the + 1 nucleosome. Furthermore, the loss of INO80 also leads to the shift of promoter-proximal RNAPII toward the alternative pausing site in mouse embryonic stem cells. CONCLUSIONS Based on our collective results, we hypothesize that the highly conserved chromatin remodeler Ino80p is essential in establishing intact RNAPII pausing during early transcription elongation in various organisms, from budding yeast to mouse.
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Affiliation(s)
- Youngseo Cheon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea
| | - Sungwook Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea
| | - Taemook Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea
| | - Daehee Hwang
- School of Biological Sciences, Seoul National University, Seoul, 08826, South Korea
| | - Daeyoup Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea.
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