1
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Poulet A, Mishra LN, Téletchéa S, Hayes JJ, Jacob Y, Thiriet C, Duc C. Identification and characterization of histones in Physarum polycephalum evidence a phylogenetic vicinity of Mycetozoans to the animal kingdom. NAR Genom Bioinform 2021; 3:lqab107. [PMID: 34805990 PMCID: PMC8600027 DOI: 10.1093/nargab/lqab107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/12/2021] [Accepted: 11/10/2021] [Indexed: 02/06/2023] Open
Abstract
Physarum polycephalum belongs to Mycetozoans, a phylogenetic clade apart from the animal, plant and fungus kingdoms. Histones are nuclear proteins involved in genome organization and regulation and are among the most evolutionary conserved proteins within eukaryotes. Therefore, this raises the question of their conservation in Physarum and the position of this organism within the eukaryotic phylogenic tree based on histone sequences. We carried out a comprehensive study of histones in Physarum polycephalum using genomic, transcriptomic and molecular data. Our results allowed to identify the different isoforms of the core histones H2A, H2B, H3 and H4 which exhibit strong conservation of amino acid residues previously identified as subject to post-translational modifications. Furthermore, we also identified the linker histone H1, the most divergent histone, and characterized a large number of its PTMs by mass spectrometry. We also performed an in-depth investigation of histone genes and transcript structures. Histone proteins are highly conserved in Physarum and their characterization will contribute to a better understanding of the polyphyletic Mycetozoan group. Our data reinforce that P. polycephalum is evolutionary closer to animals than plants and located at the crown of the eukaryotic tree. Our study provides new insights in the evolutionary history of Physarum and eukaryote lineages.
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Affiliation(s)
- Axel Poulet
- Department of Molecular, Cellular and Developmental Biology, Faculty of Arts and Sciences, Yale University, New Haven, CT 06520-8103, USA
| | - Laxmi Narayan Mishra
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester 14620 NY, USA
| | - Stéphane Téletchéa
- Conception de protéines in silico, Université de Nantes, CNRS, UFIP, UMR 6286, Nantes, France
| | - Jeffrey J Hayes
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester 14620 NY, USA
| | - Yannick Jacob
- Department of Molecular, Cellular and Developmental Biology, Faculty of Arts and Sciences, Yale University, New Haven, CT 06520-8103, USA
| | - Christophe Thiriet
- Epigénétique et dynamique de la chromatine, Université de Nantes, CNRS, UFIP, UMR 6286, Nantes, France
| | - Céline Duc
- Epigénétique et dynamique de la chromatine, Université de Nantes, CNRS, UFIP, UMR 6286, Nantes, France
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2
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Wiedermannová J, Krásný L. β-CASP proteins removing RNA polymerase from DNA: when a torpedo is needed to shoot a sitting duck. Nucleic Acids Res 2021; 49:10221-10234. [PMID: 34551438 PMCID: PMC8501993 DOI: 10.1093/nar/gkab803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022] Open
Abstract
During the first step of gene expression, RNA polymerase (RNAP) engages DNA to transcribe RNA, forming highly stable complexes. These complexes need to be dissociated at the end of transcription units or when RNAP stalls during elongation and becomes an obstacle (‘sitting duck’) to further transcription or replication. In this review, we first outline the mechanisms involved in these processes. Then, we explore in detail the torpedo mechanism whereby a 5′–3′ RNA exonuclease (torpedo) latches itself onto the 5′ end of RNA protruding from RNAP, degrades it and upon contact with RNAP, induces dissociation of the complex. This mechanism, originally described in Eukaryotes and executed by Xrn-type 5′–3′ exonucleases, was recently found in Bacteria and Archaea, mediated by β-CASP family exonucleases. We discuss the mechanistic aspects of this process across the three kingdoms of life and conclude that 5′–3′ exoribonucleases (β-CASP and Xrn families) involved in the ancient torpedo mechanism have emerged at least twice during evolution.
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Affiliation(s)
- Jana Wiedermannová
- Correspondence may also be addressed to Jana Wiedermannová. Tel: +44 191 208 3226; Fax: +44 191 208 3205;
| | - Libor Krásný
- To whom correspondence should be addressed. Tel: +420 241063208;
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3
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Lesman D, Rodriguez Y, Rajakumar D, Wein N. U7 snRNA, a Small RNA with a Big Impact in Gene Therapy. Hum Gene Ther 2021; 32:1317-1329. [PMID: 34139889 DOI: 10.1089/hum.2021.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The uridine-rich 7 (U7) small nuclear RNA (snRNA) is a component of a small nuclear ribonucleoprotein (snRNP) complex. U7 snRNA naturally contains an antisense sequence that identifies histone premessenger RNAs (pre-mRNAs) and is involved in their 3' end processing. By altering this antisense sequence, researchers have turned U7 snRNA into a versatile tool for targeting pre-mRNAs and modifying splicing. Encapsulating a modified U7 snRNA into a viral vector such as adeno-associated virus (also referred as vectorized exon skipping/inclusion, or VES/VEI) enables the delivery of this highly efficacious splicing modulator into a range of cell lines, primary cells, and tissues. In addition, and in contrast to antisense oligonucleotides, viral delivery of U7 snRNA enables long-term expression of antisense sequences in the nucleus as part of a stable snRNP complex. As a result, VES/VEI has emerged as a promising therapeutic platform for treating a large variety of human diseases caused by errors in pre-mRNA splicing or its regulation. Here we provide an overview of U7 snRNA's natural function and its applications in gene therapy.
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Affiliation(s)
- Daniel Lesman
- Center for Gene Therapy, The Research Institute, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Yacidzohara Rodriguez
- Center for Gene Therapy, The Research Institute, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Dhanarajan Rajakumar
- Center for Gene Therapy, The Research Institute, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Nicolas Wein
- Center for Gene Therapy, The Research Institute, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatric, The Ohio State University, Columbus, Ohio, USA
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4
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Sun Y, Zhang Y, Aik WS, Yang XC, Marzluff WF, Walz T, Dominski Z, Tong L. Structure of an active human histone pre-mRNA 3'-end processing machinery. Science 2020; 367:700-703. [PMID: 32029631 DOI: 10.1126/science.aaz7758] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/31/2019] [Indexed: 01/10/2023]
Abstract
The 3'-end processing machinery for metazoan replication-dependent histone precursor messenger RNAs (pre-mRNAs) contains the U7 small nuclear ribonucleoprotein and shares the key cleavage module with the canonical cleavage and polyadenylation machinery. We reconstituted an active human histone pre-mRNA processing machinery using 13 recombinant proteins and two RNAs and determined its structure by cryo-electron microscopy. The overall structure is highly asymmetrical and resembles an amphora with one long handle. We captured the pre-mRNA in the active site of the endonuclease, the 73-kilodalton subunit of the cleavage and polyadenylation specificity factor, poised for cleavage. The endonuclease and the entire cleavage module undergo extensive rearrangements for activation, triggered through the recognition of the duplex between the authentic pre-mRNA and U7 small nuclear RNA (snRNA). Our study also has notable implications for understanding canonical and snRNA 3'-end processing.
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Affiliation(s)
- Yadong Sun
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Yixiao Zhang
- Laboratory of Molecular Electron Microscopy, Rockefeller University, New York, NY 10065, USA
| | - Wei Shen Aik
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Xiao-Cui Yang
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - William F Marzluff
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Thomas Walz
- Laboratory of Molecular Electron Microscopy, Rockefeller University, New York, NY 10065, USA.
| | - Zbigniew Dominski
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. .,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
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5
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Bucholc K, Aik WS, Yang XC, Wang K, Zhou ZH, Dadlez M, Marzluff WF, Tong L, Dominski Z. Composition and processing activity of a semi-recombinant holo U7 snRNP. Nucleic Acids Res 2020; 48:1508-1530. [PMID: 31819999 PMCID: PMC7026596 DOI: 10.1093/nar/gkz1148] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/29/2019] [Accepted: 11/25/2019] [Indexed: 11/14/2022] Open
Abstract
In animal cells, replication-dependent histone pre-mRNAs are cleaved at the 3' end by U7 snRNP consisting of two core components: a ∼60-nucleotide U7 snRNA and a ring of seven proteins, with Lsm10 and Lsm11 replacing the spliceosomal SmD1 and SmD2. Lsm11 interacts with FLASH and together they recruit the endonuclease CPSF73 and other polyadenylation factors, forming catalytically active holo U7 snRNP. Here, we assembled core U7 snRNP bound to FLASH from recombinant components and analyzed its appearance by electron microscopy and ability to support histone pre-mRNA processing in the presence of polyadenylation factors from nuclear extracts. We demonstrate that semi-recombinant holo U7 snRNP reconstituted in this manner has the same composition and functional properties as endogenous U7 snRNP, and accurately cleaves histone pre-mRNAs in a reconstituted in vitro processing reaction. We also demonstrate that the U7-specific Sm ring assembles efficiently in vitro on a spliceosomal Sm site but the engineered U7 snRNP is functionally impaired. This approach offers a unique opportunity to study the importance of various regions in the Sm proteins and U7 snRNA in 3' end processing of histone pre-mRNAs.
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Affiliation(s)
- Katarzyna Bucholc
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Wei Shen Aik
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Xiao-Cui Yang
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kaituo Wang
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Z Hong Zhou
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Michał Dadlez
- Department of Biophysics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland.,Institute of Genetics and Biotechnology, Warsaw University, 02-106 Warsaw, Poland
| | - William F Marzluff
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Zbigniew Dominski
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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6
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Seal RL, Chen LL, Griffiths-Jones S, Lowe TM, Mathews MB, O'Reilly D, Pierce AJ, Stadler PF, Ulitsky I, Wolin SL, Bruford EA. A guide to naming human non-coding RNA genes. EMBO J 2020; 39:e103777. [PMID: 32090359 PMCID: PMC7073466 DOI: 10.15252/embj.2019103777] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/23/2020] [Accepted: 01/30/2020] [Indexed: 12/15/2022] Open
Abstract
Research on non-coding RNA (ncRNA) is a rapidly expanding field. Providing an official gene symbol and name to ncRNA genes brings order to otherwise potential chaos as it allows unambiguous communication about each gene. The HUGO Gene Nomenclature Committee (HGNC, www.genenames.org) is the only group with the authority to approve symbols for human genes. The HGNC works with specialist advisors for different classes of ncRNA to ensure that ncRNA nomenclature is accurate and informative, where possible. Here, we review each major class of ncRNA that is currently annotated in the human genome and describe how each class is assigned a standardised nomenclature.
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Affiliation(s)
- Ruth L Seal
- Department of Haematology, University of Cambridge School of Clinical Medicine, Cambridge, UK.,European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, UK
| | - Ling-Ling Chen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Science, Shanghai, China
| | - Sam Griffiths-Jones
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Todd M Lowe
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA, USA
| | - Michael B Mathews
- Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Dawn O'Reilly
- Computational Biology and Integrative Genomics Lab, MRC/CRUK Oxford Institute and Department of Oncology, University of Oxford, Oxford, UK
| | - Andrew J Pierce
- Translational Medicine, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Institute of Theoretical Chemistry, University of Vienna, Vienna, Austria.,Facultad de Ciencias, Universidad National de Colombia, Sede Bogotá, Colombia.,Santa Fe Institute, Santa Fe, USA
| | - Igor Ulitsky
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Sandra L Wolin
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - Elspeth A Bruford
- Department of Haematology, University of Cambridge School of Clinical Medicine, Cambridge, UK.,European Molecular Biology Laboratory, European Bioinformatics Institute, Hinxton, UK
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7
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Heyn P, Salmonowicz H, Rodenfels J, Neugebauer KM. Activation of transcription enforces the formation of distinct nuclear bodies in zebrafish embryos. RNA Biol 2016; 14:752-760. [PMID: 27858508 DOI: 10.1080/15476286.2016.1255397] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Nuclear bodies are cellular compartments that lack lipid bilayers and harbor specific RNAs and proteins. Recent proposals that nuclear bodies form through liquid-liquid phase separation leave the question of how different nuclear bodies maintain their distinct identities unanswered. Here we investigate Cajal bodies (CBs), histone locus bodies (HLBs) and nucleoli - involved in assembly of the splicing machinery, histone mRNA 3' end processing, and rRNA processing, respectively - in the embryos of the zebrafish, Danio rerio. We take advantage of the transcriptional silence of the 1-cell embryo and follow nuclear body appearance as zygotic transcription becomes activated. CBs are present from fertilization onwards, while HLB and nucleolar components formed foci several hours later when histone genes and rDNA became active. HLB formation was blocked by transcription inhibition, suggesting nascent histone transcripts recruit HLB components like U7 snRNP. Surprisingly, we found that U7 base-pairing with nascent histone transcripts was not required for localization to HLBs. Rather, the type of Sm ring assembled on U7 determined its targeting to HLBs or CBs; the spliceosomal Sm ring targeted snRNAs to CBs while the specialized U7 Sm-ring localized to HLBs, demonstrating the contribution of protein constituents to the distinction among nuclear bodies. Thus, nucleolar, HLB, and CB components can mix in early embryogenesis when transcription is naturally or artificially silenced. These data support a model in which transcription of specific gene loci nucleates nuclear body components with high specificity and fidelity to perform distinct regulatory functions.
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Affiliation(s)
- Patricia Heyn
- a Max Planck Institute of Molecular Cell Biology and Genetics , Dresden , Germany
| | - Hanna Salmonowicz
- a Max Planck Institute of Molecular Cell Biology and Genetics , Dresden , Germany
| | - Jonathan Rodenfels
- b Department of Molecular Biophysics & Biochemistry , Yale University , New Haven , CT , USA
| | - Karla M Neugebauer
- b Department of Molecular Biophysics & Biochemistry , Yale University , New Haven , CT , USA
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8
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Sawyer IA, Sturgill D, Sung MH, Hager GL, Dundr M. Cajal body function in genome organization and transcriptome diversity. Bioessays 2016; 38:1197-1208. [PMID: 27767214 DOI: 10.1002/bies.201600144] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Nuclear bodies contribute to non-random organization of the human genome and nuclear function. Using a major prototypical nuclear body, the Cajal body, as an example, we suggest that these structures assemble at specific gene loci located across the genome as a result of high transcriptional activity. Subsequently, target genes are physically clustered in close proximity in Cajal body-containing cells. However, Cajal bodies are observed in only a limited number of human cell types, including neuronal and cancer cells. Ultimately, Cajal body depletion perturbs splicing kinetics by reducing target small nuclear RNA (snRNA) transcription and limiting the levels of spliceosomal snRNPs, including their modification and turnover following each round of RNA splicing. As such, Cajal bodies are capable of shaping the chromatin interaction landscape and the transcriptome by influencing spliceosome kinetics. Future studies should concentrate on characterizing the direct influence of Cajal bodies upon snRNA gene transcriptional dynamics. Also see the video abstract here.
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Affiliation(s)
- Iain A Sawyer
- Department of Cell Biology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA.,Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - David Sturgill
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Myong-Hee Sung
- Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Miroslav Dundr
- Department of Cell Biology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
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9
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Sawyer IA, Dundr M. Nuclear bodies: Built to boost. J Cell Biol 2016; 213:509-11. [PMID: 27241912 PMCID: PMC4896059 DOI: 10.1083/jcb.201605049] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 05/17/2016] [Indexed: 12/18/2022] Open
Abstract
The classic archetypal function of nuclear bodies is to accelerate specific reactions within their crowded space. In this issue, Tatomer et al. (2016. J. Cell Biol http://dx.doi.org/10.1083/jcb.201504043) provide the first direct evidence that the histone locus body acts to concentrate key factors required for the proper processing of histone pre-mRNAs.
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Affiliation(s)
- Iain A Sawyer
- Department of Cell Biology, Rosalind Franklin University of Medicine and Science, Chicago Medical School, North Chicago, IL 60064 Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Miroslav Dundr
- Department of Cell Biology, Rosalind Franklin University of Medicine and Science, Chicago Medical School, North Chicago, IL 60064
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10
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Non-canonical Cajal bodies form in the nucleus of late stage avian oocytes lacking functional nucleolus. Histochem Cell Biol 2012; 138:57-73. [PMID: 22382586 DOI: 10.1007/s00418-012-0938-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2012] [Indexed: 10/28/2022]
Abstract
In the somatic cell nucleus, there are several universal domains such as nucleolus, SC35-domains, Cajal bodies (CBs) and histone locus bodies (HLBs). Among them, CBs were described more than 100 years ago; however, we still do not have a final understanding of their nature and biological significance. The giant nucleus of avian and amphibian growing oocytes represents an advantageous model for analysis of functions and biogenesis of various nuclear domains. Nevertheless, in large-sized avian oocytes that contain transcriptionally active lampbrush chromosomes, CB-like organelles have not been identified yet. Here we demonstrate that in the pigeon (Columba livia) oocyte nucleus, characterized by absence of any functional nucleoli, extrachromosomal spherical bodies contain TMG-capped spliceosomal snRNAs, core proteins of Sm snRNPs and the protein coilin typical for CBs, but not splicing factor SC35 nor the histone pre-mRNA 3'-end processing factor symplekin. The results establish that coilin-rich nuclear organelles in pigeon late-stage oocyte are not the equivalents of HLBs but belong to a group of CBs. At the same time, they do not contain the snoRNP/scaRNP protein fibrillarin involved in 2'-O-methylation of snoRNAs and snRNAs. Thus, the nucleus of late-stage pigeon oocytes houses CB-like organelles that have an unusual molecular composition and are implicated in the snRNP biogenesis pathway. These data demonstrate that snRNP-rich non-canonical CBs can form in the absence of nucleolus. We argue that pigeon oocytes represent a new promising model to investigate CB modular organization, functions and formation mechanism.
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11
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Abstract
Previously, the majority of the human genome was thought to be 'junk' DNA with no functional purpose. Over the past decade, the field of RNA research has rapidly expanded, with a concomitant increase in the number of non-protein coding RNA (ncRNA) genes identified in this 'junk'. Many of the encoded ncRNAs have already been shown to be essential for a variety of vital functions, and this wealth of annotated human ncRNAs requires standardised naming in order to aid effective communication. The HUGO Gene Nomenclature Committee (HGNC) is the only organisation authorised to assign standardised nomenclature to human genes. Of the 30,000 approved gene symbols currently listed in the HGNC database (http://www.genenames.org/search), the majority represent protein-coding genes; however, they also include pseudogenes, phenotypic loci and some genomic features. In recent years the list has also increased to include almost 3,000 named human ncRNA genes. HGNC is actively engaging with the RNA research community in order to provide unique symbols and names for each sequence that encodes an ncRNA. Most of the classical small ncRNA genes have now been provided with a unique nomenclature, and work on naming the long (>200 nucleotides) non-coding RNAs (lncRNAs) is ongoing.
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Affiliation(s)
- Mathew W Wright
- HUGO Gene Nomenclature Committee, EMBL-EBI, Wellcome Trust Genome Campus, Cambridge, CB10 1SD, UK.
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12
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A subset of Drosophila integrator proteins is essential for efficient U7 snRNA and spliceosomal snRNA 3'-end formation. Mol Cell Biol 2010; 31:328-41. [PMID: 21078872 DOI: 10.1128/mcb.00943-10] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Proper gene expression relies on a class of ubiquitously expressed, uridine-rich small nuclear RNAs (snRNAs) transcribed by RNA polymerase II (RNAPII). Vertebrate snRNAs are transcribed from a unique promoter, which is required for proper 3'-end formation, and cleavage of the nascent transcript involves the activity of a poorly understood set of proteins called the Integrator complex. To examine 3'-end formation in Drosophila melanogaster, we developed a cell-based reporter that monitors aberrant 3'-end formation of snRNA through the gain in expression of green fluorescent protein (GFP). We used this reporter in Drosophila S2 cells to determine requirements for U7 snRNA 3'-end formation and found that processing was strongly dependent upon nucleotides located within the 3' stem-loop as well as sequences likely to comprise the Drosophila equivalent of the vertebrate 3' box. Substitution of the actin promoter for the snRNA promoter abolished proper 3'-end formation, demonstrating the conserved requirement for an snRNA promoter in Drosophila. We tested the requirement for all Drosophila Integrator subunits and found that Integrators 1, 4, 9, and 11 were essential for 3'-end formation and that Integrators 3 and 10 may be dispensable for processing. Depletion of cleavage and polyadenylation factors or of histone pre-mRNA processing factors did not affect U7 snRNA processing efficiency, demonstrating that the Integrator complex does not share components with the mRNA 3'-end processing machinery. Finally, flies harboring mutations in either Integrator 4 or 7 fail to complete development and accumulate significant levels of misprocessed snRNA in the larval stages.
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13
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Menzel P, Gorodkin J, Stadler PF. The tedious task of finding homologous noncoding RNA genes. RNA (NEW YORK, N.Y.) 2009; 15:2075-82. [PMID: 19861422 PMCID: PMC2779685 DOI: 10.1261/rna.1556009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
User-driven in silico RNA homology search is still a nontrivial task. In part, this is the consequence of a limited precision of the computational tools in spite of recent exciting progress in this area, and to a certain extent, computational costs are still problematic in practice. An important, and as we argue here, dominating issue is the dependence on good curated (secondary) structural alignments of the RNAs. These are often hard to obtain, not so much because of an inherent limitation in the available data, but because they require substantial manual curation, an effort that is rarely acknowledged. Here, we qualitatively describe a realistic scenario for what a "regular user" (i.e., a nonexpert in a particular RNA family) can do in practice, and what kind of results are likely to be achieved. Despite the indisputable advances in computational RNA biology, the conclusion is discouraging: BLAST still works better or equally good as other methods unless extensive expert knowledge on the RNA family is included. However, when good curated data are available the recent development yields further improvements in finding remote homologs. Homology search beyond the reach of BLAST hence is not at all a routine task.
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Affiliation(s)
- Peter Menzel
- Section for Genetics and Bioinformatics, IBHV, and Center for Applied Bioinformatics, University of Copenhagen, DK-1870 Frederiksberg, Denmark
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14
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Mosig A, Zhu L, Stadler PF. Customized strategies for discovering distant ncRNA homologs. BRIEFINGS IN FUNCTIONAL GENOMICS AND PROTEOMICS 2009; 8:451-60. [PMID: 19779009 DOI: 10.1093/bfgp/elp035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A large fraction of non-coding RNAs is short and/or poorly conserved in sequence. Most of the longer examples, furthermore, consist of a collection of conserved structural motifs rather than a coherent globally conserved secondary structure. As a consequence, the conceptually simple problem of homology search becomes a complex and technically demanding task. Despite the best efforts of databases such as Rfam, the situation is complicated further by the sparsity of information in many--in particular prokaryotic--RNA families. In this contribution, we review recent efforts to customize sequence-based search tools for ncRNA applications. In particular, semi-global alignments and the development of methods for fragmented pattern search have brought significant practical advances. Current developments in this area focus on the integration of fragmented sequence pattern search with search algorithms for secondary structure patterns. We focus here, in particular, on strategies that can be successful in the 'twilight zone' where generic approaches from blast to infernal to start to fail.
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Affiliation(s)
- Axel Mosig
- Chair of Bioinformatics, Department of Computer Science, University of Leipzig, Härtelstrasse 16-18, D-04107 Leipzig, Germany
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Hertel J, de Jong D, Marz M, Rose D, Tafer H, Tanzer A, Schierwater B, Stadler PF. Non-coding RNA annotation of the genome of Trichoplax adhaerens. Nucleic Acids Res 2009; 37:1602-15. [PMID: 19151082 PMCID: PMC2655684 DOI: 10.1093/nar/gkn1084] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 12/22/2008] [Accepted: 12/23/2008] [Indexed: 02/06/2023] Open
Abstract
A detailed annotation of non-protein coding RNAs is typically missing in initial releases of newly sequenced genomes. Here we report on a comprehensive ncRNA annotation of the genome of Trichoplax adhaerens, the presumably most basal metazoan whose genome has been published to-date. Since blast identified only a small fraction of the best-conserved ncRNAs--in particular rRNAs, tRNAs and some snRNAs--we developed a semi-global dynamic programming tool, GotohScan, to increase the sensitivity of the homology search. It successfully identified the full complement of major and minor spliceosomal snRNAs, the genes for RNase P and MRP RNAs, the SRP RNA, as well as several small nucleolar RNAs. We did not find any microRNA candidates homologous to known eumetazoan sequences. Interestingly, most ncRNAs, including the pol-III transcripts, appear as single-copy genes or with very small copy numbers in the Trichoplax genome.
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Affiliation(s)
- Jana Hertel
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Danielle de Jong
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Manja Marz
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Dominic Rose
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Hakim Tafer
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Andrea Tanzer
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Bernd Schierwater
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
| | - Peter F. Stadler
- Bioinformatics Group, Department of Computer Science, Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, D-04107 Leipzig, Division of Ecology and Evolution, Institut für Tierökologie und Zellbiologie, Tierärztliche Hochschule Hannover, Bünteweg 17d, D-30559 Hannover, Germany, Department of Theoretical Chemistry, University of Vienna, Währingerstraβe 17, A-1090 Wien, Austria, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, RNomics Group, Fraunhofer Institut für Zelltherapie und Immunologie, Deutscher Platz 5e, D-04103 Leipzig, Germany and Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
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