1
|
Frisbie VS, Hashimoto H, Xie Y, De Luna Vitorino FN, Baeza J, Nguyen T, Yuan Z, Kiselar J, Garcia BA, Debler EW. Two DOT1 enzymes cooperatively mediate efficient ubiquitin-independent histone H3 lysine 76 tri-methylation in kinetoplastids. Nat Commun 2024; 15:2467. [PMID: 38503750 PMCID: PMC10951340 DOI: 10.1038/s41467-024-46637-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 03/04/2024] [Indexed: 03/21/2024] Open
Abstract
In higher eukaryotes, a single DOT1 histone H3 lysine 79 (H3K79) methyltransferase processively produces H3K79me2/me3 through histone H2B mono-ubiquitin interaction, while the kinetoplastid Trypanosoma brucei di-methyltransferase DOT1A and tri-methyltransferase DOT1B efficiently methylate the homologous H3K76 without H2B mono-ubiquitination. Based on structural and biochemical analyses of DOT1A, we identify key residues in the methyltransferase motifs VI and X for efficient ubiquitin-independent H3K76 methylation in kinetoplastids. Substitution of a basic to an acidic residue within motif VI (Gx6K) is essential to stabilize the DOT1A enzyme-substrate complex, while substitution of the motif X sequence VYGE by CAKS renders a rigid active-site loop flexible, implying a distinct mechanism of substrate recognition. We further reveal distinct methylation kinetics and substrate preferences of DOT1A (H3K76me0) and DOT1B (DOT1A products H3K76me1/me2) in vitro, determined by a Ser and Ala residue within motif IV, respectively, enabling DOT1A and DOT1B to mediate efficient H3K76 tri-methylation non-processively but cooperatively, and suggesting why kinetoplastids have evolved two DOT1 enzymes.
Collapse
Affiliation(s)
- Victoria S Frisbie
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Hideharu Hashimoto
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Yixuan Xie
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Francisca N De Luna Vitorino
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - Josue Baeza
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Tam Nguyen
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Zhangerjiao Yuan
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Janna Kiselar
- Case Center for Proteomics and Bioinformatics, Department of Nutrition, Case Western Reserve University, School of Medicine, Cleveland, OH, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Erik W Debler
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
2
|
Vanagas L, Muñoz D, Cristaldi C, Ganuza A, Nájera R, Bonardi MC, Turowski VR, Guzman F, Deng B, Kim K, Sullivan WJ, Angel SO. Histone variant H2B.Z acetylation is necessary for maintenance of Toxoplasma gondii biological fitness. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194943. [PMID: 37217032 PMCID: PMC10524646 DOI: 10.1016/j.bbagrm.2023.194943] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023]
Abstract
Through regulation of DNA packaging, histone proteins are fundamental to a wide array of biological processes. A variety of post-translational modifications (PTMs), including acetylation, constitute a proposed histone code that is interpreted by "reader" proteins to modulate chromatin structure. Canonical histones can be replaced with variant versions that add an additional layer of regulatory complexity. The protozoan parasite Toxoplasma gondii is unique among eukaryotes in possessing a novel variant of H2B designated H2B.Z. The combination of PTMs and the use of histone variants are important for gene regulation in T. gondii, offering new targets for drug development. In this work, T. gondii parasites were generated in which the 5 N-terminal acetylatable lysines in H2B.Z were mutated to either alanine (c-Myc-A) or arginine (c-Myc-R). The c-Myc-A mutant displayed no phenotype over than a mild defect in its ability to kill mice. The c-Myc-R mutant presented an impaired ability to grow and an increase in differentiation to latent bradyzoites. The c-Myc-R mutant was also more sensitive to DNA damage, displayed no virulence in mice, and provided protective immunity against future infection. While nucleosome composition was unaltered, key genes were abnormally expressed during in vitro bradyzoite differentiation. Our results show that regulation of the N-terminal positive charge patch of H2B.Z is important for these processes. We also show that acetylated N-terminal H2B.Z interacts with some unique proteins compared to its unacetylated counterpart; the acetylated peptide pulled down proteins associated with chromosome maintenance/segregation and cell cycle, suggesting a link between H2B.Z acetylation status and mitosis.
Collapse
Affiliation(s)
- Laura Vanagas
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina.
| | - Daniela Muñoz
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Constanza Cristaldi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Agustina Ganuza
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Rosario Nájera
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Mabel C Bonardi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina
| | - Valeria R Turowski
- Laboratorio de Bioquímica y Biología Celular de Parásitos, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA Chascomús, Prov. Buenos Aires, Argentina
| | - Fanny Guzman
- Núcleo de Biotecnología Curauma, Pontificia Universidad Católica de Valparaiso, Av. Universidad 330 Curauma, Valparaiso, Chile
| | - Bin Deng
- Department of Biology and VBRN, University of Vermont, VT, USA
| | - Kami Kim
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - William J Sullivan
- Department of Pharmacology and Toxicology, Indiana School of Medicine, Indianapolis, IN 46202, USA
| | - Sergio O Angel
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, B7130IIWA, Chascomús, Prov. Buenos Aires, Argentina.
| |
Collapse
|
3
|
Nascimento JF, Souza ROO, Alencar MB, Marsiccobetre S, Murillo AM, Damasceno FS, Girard RBMM, Marchese L, Luévano-Martinez LA, Achjian RW, Haanstra JR, Michels PAM, Silber AM. How much (ATP) does it cost to build a trypanosome? A theoretical study on the quantity of ATP needed to maintain and duplicate a bloodstream-form Trypanosoma brucei cell. PLoS Pathog 2023; 19:e1011522. [PMID: 37498954 PMCID: PMC10409291 DOI: 10.1371/journal.ppat.1011522] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 08/08/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023] Open
Abstract
ATP hydrolysis is required for the synthesis, transport and polymerization of monomers for macromolecules as well as for the assembly of the latter into cellular structures. Other cellular processes not directly related to synthesis of biomass, such as maintenance of membrane potential and cellular shape, also require ATP. The unicellular flagellated parasite Trypanosoma brucei has a complex digenetic life cycle. The primary energy source for this parasite in its bloodstream form (BSF) is glucose, which is abundant in the host's bloodstream. Here, we made a detailed estimation of the energy budget during the BSF cell cycle. As glycolysis is the source of most produced ATP, we calculated that a single parasite produces 6.0 x 1011 molecules of ATP/cell cycle. Total biomass production (which involves biomass maintenance and duplication) accounts for ~63% of the total energy budget, while the total biomass duplication accounts for the remaining ~37% of the ATP consumption, with in both cases translation being the most expensive process. These values allowed us to estimate a theoretical YATP of 10.1 (g biomass)/mole ATP and a theoretical [Formula: see text] of 28.6 (g biomass)/mole ATP. Flagellar motility, variant surface glycoprotein recycling, transport and maintenance of transmembrane potential account for less than 30% of the consumed ATP. Finally, there is still ~5.5% available in the budget that is being used for other cellular processes of as yet unknown cost. These data put a new perspective on the assumptions about the relative energetic weight of the processes a BSF trypanosome undergoes during its cell cycle.
Collapse
Affiliation(s)
- Janaina F. Nascimento
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Rodolpho O. O. Souza
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Mayke B. Alencar
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Sabrina Marsiccobetre
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Ana M. Murillo
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Flávia S. Damasceno
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Richard B. M. M. Girard
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Letícia Marchese
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Luis A. Luévano-Martinez
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Renan W. Achjian
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Jurgen R. Haanstra
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Paul A. M. Michels
- School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ariel M. Silber
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| |
Collapse
|
4
|
Vanagas L, Muñoz D, Cristaldi C, Ganuza A, Nájera R, Bonardi MC, Turowski VR, Guzman F, Deng B, Kim K, Sullivan WJ, Angel SO. Histone variant H2B.Z acetylation is necessary for maintenance of Toxoplasma gondii biological fitness. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528480. [PMID: 36824796 PMCID: PMC9949044 DOI: 10.1101/2023.02.14.528480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Through regulation of DNA packaging, histone proteins are fundamental to a wide array of biological processes. A variety of post-translational modifications (PTMs), including acetylation, constitute a proposed histone code that is interpreted by "reader" proteins to modulate chromatin structure. Canonical histones can be replaced with variant versions that add an additional layer of regulatory complexity. The protozoan parasite Toxoplasma gondii is unique among eukaryotes in possessing a novel variant of H2B designated H2B.Z. The combination of PTMs and the use of histone variants is important for gene regulation in T. gondii, offering new targets for drug development. In this work, T. gondii parasites were generated in which the 5 N-terminal acetylatable lysines in H2B.Z were mutated to either alanine (c-Myc-A) or arginine (c-Myc-R). c-Myc-A mutant only displayed a mild effect in its ability to kill mice. c-Myc-R mutant presented an impaired ability to grow and an increase in differentiation to latent bradyzoites. This mutant line was also more sensitive to DNA damage, displayed no virulence in mice, and provided protective immunity against future infection. While nucleosome composition was unaltered, key genes were abnormally expressed during in vitro bradyzoite differentiation. Our results show that the N-terminal positive charge patch of H2B.Z is important for these procceses. Pull down assays with acetylated N-terminal H2B.Z peptide and unacetylated one retrieved common and differential interactors. Acetylated peptide pulled down proteins associated with chromosome maintenance/segregation and cell cycle, opening the question of a possible link between H2B.Z acetylation status and mitosis.
Collapse
Affiliation(s)
- Laura Vanagas
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Daniela Muñoz
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Constanza Cristaldi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Agustina Ganuza
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Rosario Nájera
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Mabel C. Bonardi
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Valeria R. Turowski
- Laboratorio de Bioquímica y Biología Celular de Parásitos, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| | - Fanny Guzman
- Núcleo de Biotecnología Curauma, Pontificia Universidad Católica de Valparaiso. Av. Universidad 330 Curauma, Valparaiso
| | - Bin Deng
- Department of Biology and VBRN, University of Vermont, Vermont, USA
| | - Kami Kim
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612
| | - William J. Sullivan
- Department of Pharmacology and Toxicology, Indiana School of Medicine, Indianapolis, Indiana 46202, USA
| | - Sergio O. Angel
- Laboratorio de Parasitología Molecular, INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina
| |
Collapse
|
5
|
Maree JP, Tvardovskiy A, Ravnsborg T, Jensen ON, Rudenko G, Patterton HG. Trypanosoma brucei histones are heavily modified with combinatorial post-translational modifications and mark Pol II transcription start regions with hyperacetylated H2A. Nucleic Acids Res 2022; 50:9705-9723. [PMID: 36095123 PMCID: PMC9508842 DOI: 10.1093/nar/gkac759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 08/09/2022] [Accepted: 08/30/2022] [Indexed: 11/12/2022] Open
Abstract
Trypanosomes diverged from the main eukaryotic lineage about 600 million years ago, and display some unusual genomic and epigenetic properties that provide valuable insight into the early processes employed by eukaryotic ancestors to regulate chromatin-mediated functions. We analysed Trypanosoma brucei core histones by high mass accuracy middle-down mass spectrometry to map core histone post-translational modifications (PTMs) and elucidate cis-histone combinatorial PTMs (cPTMs). T. brucei histones are heavily modified and display intricate cPTMs patterns, with numerous hypermodified cPTMs that could contribute to the formation of non-repressive euchromatic states. The Trypanosoma brucei H2A C-terminal tail is hyperacetylated, containing up to five acetylated lysine residues. MNase-ChIP-seq revealed a striking enrichment of hyperacetylated H2A at Pol II transcription start regions, and showed that H2A histones that are hyperacetylated in different combinations localised to different genomic regions, suggesting distinct epigenetic functions. Our genomics and proteomics data provide insight into the complex epigenetic mechanisms used by this parasite to regulate a genome that lacks the transcriptional control mechanisms found in later-branched eukaryotes. The findings further demonstrate the complexity of epigenetic mechanisms that were probably shared with the last eukaryotic common ancestor.
Collapse
Affiliation(s)
- Johannes P Maree
- Department of Biochemistry, Stellenbosch University, Stellenbosch 7600, South Africa
| | - Andrey Tvardovskiy
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, and Center for Epigenetics, University of Southern Denmark, Odense M DK-5230, Denmark
| | - Tina Ravnsborg
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, and Center for Epigenetics, University of Southern Denmark, Odense M DK-5230, Denmark
| | - Ole N Jensen
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, and Center for Epigenetics, University of Southern Denmark, Odense M DK-5230, Denmark
| | - Gloria Rudenko
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Hugh-G Patterton
- Center for Bioinformatics and Computational Biology, Stellenbosch University, Stellenbosch 7600, South Africa
| |
Collapse
|
6
|
Rosón JN, Vitarelli MDO, Costa-Silva HM, Pereira KS, Pires DDS, Lopes LDS, Cordeiro B, Kraus AJ, Cruz KNT, Calderano SG, Fragoso SP, Siegel TN, Elias MC, da Cunha JPC. H2B.V demarcates divergent strand-switch regions, some tDNA loci, and genome compartments in Trypanosoma cruzi and affects parasite differentiation and host cell invasion. PLoS Pathog 2022; 18:e1009694. [PMID: 35180281 PMCID: PMC8893665 DOI: 10.1371/journal.ppat.1009694] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 03/03/2022] [Accepted: 01/31/2022] [Indexed: 11/19/2022] Open
Abstract
Histone variants play a crucial role in chromatin structure organization and gene expression. Trypanosomatids have an unusual H2B variant (H2B.V) that is known to dimerize with the variant H2A.Z generating unstable nucleosomes. Previously, we found that H2B.V protein is enriched in tissue-derived trypomastigote (TCT) life forms, a nonreplicative stage of Trypanosoma cruzi, suggesting that this variant may contribute to the differences in chromatin structure and global transcription rates observed among parasite life forms. Here, we performed the first genome-wide profiling of histone localization in T. cruzi using epimastigotes and TCT life forms, and we found that H2B.V was preferentially located at the edges of divergent transcriptional strand switch regions, which encompass putative transcriptional start regions; at some tDNA loci; and between the conserved and disrupted genome compartments, mainly at trans-sialidase, mucin and MASP genes. Remarkably, the chromatin of TCT forms was depleted of H2B.V-enriched peaks in comparison to epimastigote forms. Interactome assays indicated that H2B.V associated specifically with H2A.Z, bromodomain factor 2, nucleolar proteins and a histone chaperone, among others. Parasites expressing reduced H2B.V levels were associated with higher rates of parasite differentiation and mammalian cell infectivity. Taken together, H2B.V demarcates critical genomic regions and associates with regulatory chromatin proteins, suggesting a scenario wherein local chromatin structures associated with parasite differentiation and invasion are regulated during the parasite life cycle.
Collapse
Affiliation(s)
- Juliana Nunes Rosón
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina–UNIFESP, São Paulo, Brazil
| | - Marcela de Oliveira Vitarelli
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Héllida Marina Costa-Silva
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Kamille Schmitt Pereira
- Department of Bioprocesses and Biotechnology, Universidade Federal do Paraná, Curitiba, Brazil
- Laboratory of Molecular and Systems Biology of Trypanosomatids, Carlos Chagas Institute, FIOCRUZ, Curitiba, Brazil
| | - David da Silva Pires
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Leticia de Sousa Lopes
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Barbara Cordeiro
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Amelie J. Kraus
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität in Munich, Munich, Germany
- Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universitäat in Munch, Munich, Germany
| | - Karin Navarro Tozzi Cruz
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Simone Guedes Calderano
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Stenio Perdigão Fragoso
- Department of Bioprocesses and Biotechnology, Universidade Federal do Paraná, Curitiba, Brazil
- Laboratory of Molecular and Systems Biology of Trypanosomatids, Carlos Chagas Institute, FIOCRUZ, Curitiba, Brazil
| | - T. Nicolai Siegel
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität in Munich, Munich, Germany
- Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universitäat in Munch, Munich, Germany
| | - Maria Carolina Elias
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
| | - Julia Pinheiro Chagas da Cunha
- Laboratory of Cell Cycle, Butantan Institute, São Paulo, Brazil
- Center of Toxins, Immune Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, Brazil
- * E-mail:
| |
Collapse
|
7
|
Staneva DP, Carloni R, Auchynnikava T, Tong P, Rappsilber J, Jeyaprakash AA, Matthews KR, Allshire RC. A systematic analysis of Trypanosoma brucei chromatin factors identifies novel protein interaction networks associated with sites of transcription initiation and termination. Genome Res 2021; 31:2138-2154. [PMID: 34407985 PMCID: PMC8559703 DOI: 10.1101/gr.275368.121] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 08/09/2021] [Indexed: 02/07/2023]
Abstract
Nucleosomes composed of histones are the fundamental units around which DNA is wrapped to form chromatin. Transcriptionally active euchromatin or repressive heterochromatin is regulated in part by the addition or removal of histone post-translational modifications (PTMs) by "writer" and "eraser" enzymes, respectively. Nucleosomal PTMs are recognized by a variety of "reader" proteins that alter gene expression accordingly. The histone tails of the evolutionarily divergent eukaryotic parasite Trypanosoma brucei have atypical sequences and PTMs distinct from those often considered universally conserved. Here we identify 65 predicted readers, writers, and erasers of histone acetylation and methylation encoded in the T. brucei genome and, by epitope tagging, systemically localize 60 of them in the parasite's bloodstream form. ChIP-seq shows that 15 candidate proteins associate with regions of RNAPII transcription initiation. Eight other proteins show a distinct distribution with specific peaks at a subset of RNAPII transcription termination regions marked by RNAPIII-transcribed tRNA and snRNA genes. Proteomic analyses identify distinct protein interaction networks comprising known chromatin regulators and novel trypanosome-specific components. Notably, several SET- and Bromo-domain protein networks suggest parallels to RNAPII promoter-associated complexes in conventional eukaryotes. Further, we identify likely components of TbSWR1 and TbNuA4 complexes whose enrichment coincides with the SWR1-C exchange substrate H2A.Z at RNAPII transcription start regions. The systematic approach used provides details of the composition and organization of the chromatin regulatory machinery in T. brucei and establishes a route to explore divergence from eukaryotic norms in an evolutionarily ancient but experimentally accessible eukaryote.
Collapse
Affiliation(s)
- Desislava P Staneva
- Wellcome Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Institute of Immunology and Infection Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
| | - Roberta Carloni
- Wellcome Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Institute of Immunology and Infection Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
| | - Tatsiana Auchynnikava
- Wellcome Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | | | - Juri Rappsilber
- Wellcome Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
- Institute of Biotechnology, Technische Universität, 13355 Berlin, Germany
| | - A Arockia Jeyaprakash
- Wellcome Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| | - Keith R Matthews
- Institute of Immunology and Infection Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
| | - Robin C Allshire
- Wellcome Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, United Kingdom
| |
Collapse
|
8
|
Marcianò G, Ishii M, Nerusheva OO, Akiyoshi B. Kinetoplastid kinetochore proteins KKT2 and KKT3 have unique centromere localization domains. J Cell Biol 2021; 220:212224. [PMID: 34081090 PMCID: PMC8178753 DOI: 10.1083/jcb.202101022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/29/2021] [Accepted: 05/12/2021] [Indexed: 12/31/2022] Open
Abstract
The kinetochore is the macromolecular protein complex that assembles onto centromeric DNA and binds spindle microtubules. Evolutionarily divergent kinetoplastids have an unconventional set of kinetochore proteins. It remains unknown how kinetochores assemble at centromeres in these organisms. Here, we characterize KKT2 and KKT3 in the kinetoplastid parasite Trypanosoma brucei. In addition to the N-terminal kinase domain and C-terminal divergent polo boxes, these proteins have a central domain of unknown function. We show that KKT2 and KKT3 are important for the localization of several kinetochore proteins and that their central domains are sufficient for centromere localization. Crystal structures of the KKT2 central domain from two divergent kinetoplastids reveal a unique zinc-binding domain (termed the CL domain for centromere localization), which promotes its kinetochore localization in T. brucei. Mutations in the equivalent domain in KKT3 abolish its kinetochore localization and function. Our work shows that the unique central domains play a critical role in mediating the centromere localization of KKT2 and KKT3.
Collapse
Affiliation(s)
| | - Midori Ishii
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Bungo Akiyoshi
- Department of Biochemistry, University of Oxford, Oxford, UK
| |
Collapse
|
9
|
Kraus AJ, Vanselow JT, Lamer S, Brink BG, Schlosser A, Siegel TN. Distinct roles for H4 and H2A.Z acetylation in RNA transcription in African trypanosomes. Nat Commun 2020; 11:1498. [PMID: 32198348 PMCID: PMC7083915 DOI: 10.1038/s41467-020-15274-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 03/01/2020] [Indexed: 12/29/2022] Open
Abstract
Despite histone H2A variants and acetylation of histones occurring in almost every eukaryotic organism, it has been difficult to establish direct functional links between canonical histones or H2A variant acetylation, deposition of H2A variants and transcription. To disentangle these complex interdependent processes, we devised a highly sensitive strategy for quantifying histone acetylation levels at specific genomic loci. Taking advantage of the unusual genome organization in Trypanosoma brucei, we identified 58 histone modifications enriched at transcription start sites (TSSs). Furthermore, we found TSS-associated H4 and H2A.Z acetylation to be mediated by two different histone acetyltransferases, HAT2 and HAT1, respectively. Whereas depletion of HAT2 decreases H2A.Z deposition and shifts the site of transcription initiation, depletion of HAT1 does not affect H2A.Z deposition but reduces total mRNA levels by 50%. Thus, specifically reducing H4 or H2A.Z acetylation levels enabled us to reveal distinct roles for these modifications in H2A.Z deposition and RNA transcription. Histone modification and deposition are key regulators of transcription. Here, Kraus et al. provide a quantitative histone acetylome for Trypanosoma brucei, identify histone modifications enriched at transcription start sites, and show how H4 and H2A.Z acetylation affect histone deposition and transcription in trypanosomes.
Collapse
Affiliation(s)
- Amelie J Kraus
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität München, 80752, Munich, Germany.,Biomedical Center Munich, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, 82152, Planegg-Martinsried, Germany.,Research Center for Infectious Diseases, University of Würzburg, 97080, Würzburg, Germany.,Institute for Epigenetics and Stem Cells, Helmholtz Zentrum München, Munich, Germany
| | - Jens T Vanselow
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, 97080, Würzburg, Germany.,German Federal Institute for Risk Assessment, Unit Safety of Chemicals, Department Chemicals and Product Safety, Berlin, Germany
| | - Stephanie Lamer
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, 97080, Würzburg, Germany
| | - Benedikt G Brink
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität München, 80752, Munich, Germany.,Biomedical Center Munich, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, 82152, Planegg-Martinsried, Germany
| | - Andreas Schlosser
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, 97080, Würzburg, Germany
| | - T Nicolai Siegel
- Department of Veterinary Sciences, Experimental Parasitology, Ludwig-Maximilians-Universität München, 80752, Munich, Germany. .,Biomedical Center Munich, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, 82152, Planegg-Martinsried, Germany. .,Research Center for Infectious Diseases, University of Würzburg, 97080, Würzburg, Germany.
| |
Collapse
|
10
|
Nuclear Phosphatidylinositol 5-Phosphatase Is Essential for Allelic Exclusion of Variant Surface Glycoprotein Genes in Trypanosomes. Mol Cell Biol 2019; 39:MCB.00395-18. [PMID: 30420356 DOI: 10.1128/mcb.00395-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/23/2018] [Indexed: 11/20/2022] Open
Abstract
Allelic exclusion of variant surface glycoprotein (VSG) genes is essential for African trypanosomes to evade the host antibody response by antigenic variation. The mechanisms by which this parasite expresses only one of its ∼2,000 VSG genes at a time are unknown. We show that nuclear phosphatidylinositol 5-phosphatase (PIP5Pase) interacts with repressor activator protein 1 (RAP1) in a multiprotein complex and functions in the control of VSG allelic exclusion. RAP1 binds PIP5Pase substrate phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3], and catalytic mutation of PIP5Pase that inhibits PI(3,4,5)P3 dephosphorylation results in simultaneous transcription of VSGs from all telomeric expression sites (ESs) and from silent subtelomeric VSG arrays. PIP5Pase and RAP1 bind to telomeric ESs, especially at 70-bp repeats and telomeres, and their binding is altered by PIP5Pase inactivation or knockdown, implying changes in ES chromatin organization. Our data suggest a model whereby PIP5Pase controls PI(3,4,5)P3 binding by RAP1 and, thus, RAP1 silencing of telomeric and subtelomeric VSG genes. Hence, allelic exclusion of VSG genes may entail control of nuclear phosphoinositides.
Collapse
|
11
|
Chen R, Mao Y, Wang J, Liu M, Qiao Y, Zheng L, Su Y, Ke Q, Zheng W. Molecular mechanisms of an antimicrobial peptide piscidin (Lc-pis) in a parasitic protozoan, Cryptocaryon irritans. BMC Genomics 2018; 19:192. [PMID: 29703140 PMCID: PMC6389114 DOI: 10.1186/s12864-018-4565-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 02/22/2018] [Indexed: 12/15/2022] Open
Abstract
Background Cryptocaryon irritans is an obligate parasitic ciliate protozoan that can infect various commercially important mariculture fish species and cause high lethality and economic loss. Current methods of controlling this parasite with chemicals or antibiotics are widely considered to be environmentally harmful. Piscidins with broad spectrum antibacterial, antifungal and antiviral activities were found to have potent activity against C. irritans. Little, however, has been understood about the killing mechanisms of piscidins in parasites. Results In total, 57.12, 50.44, 55.86 and 47.87 million raw reads were generated from untreated theront and trophont, and piscidin (Lc-pis) treated theront and trophont libraries, respectively. After de novo assembly, 966,609 unigenes were generated with an average length of 420 bp: among these, 618,629 unigenes showed identity with sequences in one or more databases, with some showing to be significantly manipulated by Lc-pis treatment. The species classification showed that more than 25.8% unigenes from trophonts were homologous to the large yellow croaker (Larimichthys crocea) and less than 3.8% unigenes from theronts were matched. The homologous unigenes demonstrated that the tissue from host could exist in trophonts and might be transported to parasite via vesicular transports. Our analysis showed that regulatory transcripts were involved in vesicular trafficking. Among transcripts induced by Lc-pis, most genes up-regulated in treated and untreated theronts were involved in cell migration and apoptosis related pathways. Few transcripts were found to be down-regulated in treated and untreated trophonts related to cell structure and migration after treatment. Conclusions This is the first transcriptome analysis of C. irritans exposed to Lc-pis, which enhanced the genomic resources and provided novel insights into molecular mechanisms of ciliates treated by cationic antimicrobial peptide. Our comprehensive transcriptome analysis can facilitate the identification of potential drug targets and vaccines candidates for controlling this devastating fish pathogen. Electronic supplementary material The online version of this article (10.1186/s12864-018-4565-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ruanni Chen
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China.,State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co., Ltd, Ningde, Fujian, 352103, China
| | - Yong Mao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China.,State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co., Ltd, Ningde, Fujian, 352103, China
| | - Jun Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China.,State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co., Ltd, Ningde, Fujian, 352103, China
| | - Min Liu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Ying Qiao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Libing Zheng
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China
| | - Yongquan Su
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, 361005, China. .,State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co., Ltd, Ningde, Fujian, 352103, China.
| | - Qiaozhen Ke
- State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co., Ltd, Ningde, Fujian, 352103, China
| | - Weiqiang Zheng
- State Key Laboratory of Large Yellow Croaker Breeding, Fujian Fuding Seagull Fishing Food Co., Ltd, Ningde, Fujian, 352103, China
| |
Collapse
|
12
|
Martínez-Calvillo S, Romero-Meza G, Vizuet-de-Rueda JC, Florencio-Martínez LE, Manning-Cela R, Nepomuceno-Mejía T. Epigenetic Regulation of Transcription in Trypanosomatid Protozoa. Curr Genomics 2018; 19:140-149. [PMID: 29491742 PMCID: PMC5814962 DOI: 10.2174/1389202918666170911163517] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/13/2017] [Accepted: 04/18/2017] [Indexed: 12/15/2022] Open
Abstract
The Trypanosomatid family includes flagellated parasites that cause fatal human diseases. Remarkably, protein-coding genes in these organisms are positioned in long tandem arrays that are transcribed polycistronically. However, the knowledge about regulation of transcription initiation and termination in trypanosomatids is scarce. The importance of epigenetic regulation in these processes has become evident in the last years, as distinctive histone modifications and histone variants have been found in transcription initiation and termination regions. Moreover, multiple chromatin-related proteins have been identified and characterized in trypanosomatids, including histone-modifying enzymes, effector complexes, chromatin-remodelling enzymes and histone chaperones. Notably, base J, a modified thymine residue present in the nuclear DNA of trypanosomatids, has been implicated in transcriptional regulation. Here we review the current knowledge on epigenetic control of transcription by all three RNA polymerases in this group of early-diverged eukaryotes.
Collapse
Affiliation(s)
- Santiago Martínez-Calvillo
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Gabriela Romero-Meza
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Juan C. Vizuet-de-Rueda
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Luis E. Florencio-Martínez
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| | - Rebeca Manning-Cela
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Av. IPN 2508, México, D.F., CP 07360, México
| | - Tomás Nepomuceno-Mejía
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México. Av. de los Barrios 1, Col. Los Reyes Iztacala, Tlalnepantla, Edo. de México, CP 54090, México
| |
Collapse
|
13
|
Recognition of hyperacetylated N-terminus of H2AZ by TbBDF2 from Trypanosoma brucei. Biochem J 2017; 474:3817-3830. [DOI: 10.1042/bcj20170619] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/05/2017] [Accepted: 10/09/2017] [Indexed: 12/17/2022]
Abstract
Histone modification plays an important role in various biological processes, including gene expression regulation. Bromodomain, as one of histone readers, recognizes specifically the ε-N-lysine acetylation (KAc) of histone. Although the bromodomains and histone acetylation sites of Trypanosoma brucei (T. brucei), a lethal parasite responsible for sleeping sickness in human and nagana in cattle, have been identified, how acetylated histones are recognized by bromodomains is still unknown. Here, the bromodomain factor 2 (TbBDF2) from T. brucei was identified to be located in the nucleolus and bind to the hyperacetylated N-terminus of H2AZ which dimerizes with H2BV. The bromodomain of TbBDF2 (TbBDF2-BD) displays a conserved fold that comprises a left-handed bundle of four α-helices (αZ, αA, αB, αC), linked by loop regions of variable length (ZA and BC loops), which form the KAc-binding pocket. NMR chemical shift perturbation further revealed that TbBDF2-BD binds to the hyperacetylated N-terminus of H2AZ through its KAc-binding pocket. By structure-based virtual screening combining with the ITC experiment, a small molecule compound, GSK2801, was shown to have high affinity to TbBDF2-BD. GSK2801 and the hyperacetylated N-terminus of H2AZ have similar binding sites on TbBDF2-BD. In addition, GSK2801 competitively inhibits the hyperacetylated N-terminus of H2AZ binding to TbBDF2-BD. After treatment of GSK2801, cell growth was inhibited and localization of TbBDF2 was disrupted. Our results report a novel bromodomain-histone recognition by TbBDF2-BD and imply that TbBDF2 may serve as a potential chemotherapeutic target for the treatment of trypanosomiasis.
Collapse
|
14
|
Wedel C, Siegel TN. Genome-wide analysis of chromatin structures in Trypanosoma brucei using high-resolution MNase-ChIP-seq. Exp Parasitol 2017; 180:2-12. [PMID: 28286326 DOI: 10.1016/j.exppara.2017.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 02/24/2017] [Accepted: 03/07/2017] [Indexed: 11/16/2022]
Abstract
Specific DNA-protein interactions are the basis for many important cellular mechanisms like the regulation of gene expression or replication. Knowledge about the precise genomic locations of DNA-protein interactions is important because it provides insight into the regulation of these processes. Recently, we have adapted an approach that combines micrococcal nuclease (MNase) digestion of chromatin with chromatin immunoprecipitation in Trypanosoma brucei. Here, we describe in detail how this method can be used to map the genome-wide distribution of nucleosomes or other DNA-binding proteins at high resolution in T. brucei.
Collapse
Affiliation(s)
- Carolin Wedel
- Research Center for Infectious Diseases (ZINF), University of Würzburg, Josef-Schneider-Straße 2 / Bau D15, 97080 Würzburg, Germany
| | - T Nicolai Siegel
- Research Center for Infectious Diseases (ZINF), University of Würzburg, Josef-Schneider-Straße 2 / Bau D15, 97080 Würzburg, Germany.
| |
Collapse
|
15
|
Picchi GFA, Zulkievicz V, Krieger MA, Zanchin NT, Goldenberg S, de Godoy LMF. Post-translational Modifications of Trypanosoma cruzi Canonical and Variant Histones. J Proteome Res 2017; 16:1167-1179. [DOI: 10.1021/acs.jproteome.6b00655] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | - Vanessa Zulkievicz
- Instituto Carlos Chagas, Fiocruz Parana, Curitiba, Paraná 81350-010, Brazil
| | - Marco A. Krieger
- Instituto Carlos Chagas, Fiocruz Parana, Curitiba, Paraná 81350-010, Brazil
| | - Nilson T. Zanchin
- Instituto Carlos Chagas, Fiocruz Parana, Curitiba, Paraná 81350-010, Brazil
| | - Samuel Goldenberg
- Instituto Carlos Chagas, Fiocruz Parana, Curitiba, Paraná 81350-010, Brazil
| | | |
Collapse
|
16
|
Leandro de Jesus TC, Calderano SG, Vitorino FNDL, Llanos RP, Lopes MDC, de Araújo CB, Thiemann OH, Reis MDS, Elias MC, Chagas da Cunha JP. Quantitative Proteomic Analysis of Replicative and Nonreplicative Forms Reveals Important Insights into Chromatin Biology of Trypanosoma cruzi. Mol Cell Proteomics 2016; 16:23-38. [PMID: 27852749 DOI: 10.1074/mcp.m116.061200] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/02/2016] [Indexed: 01/02/2023] Open
Abstract
Chromatin associated proteins are key regulators of many important processes in the cell. Trypanosoma cruzi, a protozoa flagellate that causes Chagas disease, alternates between replicative and nonreplicative forms accompanied by a shift on global transcription levels and by changes in its chromatin architecture. Here, we investigated the T. cruzi chromatin proteome using three different protocols and compared it between replicative (epimastigote) and nonreplicative (trypomastigote) forms by high-resolution mass spectrometry. More than 2000 proteins were identified and quantified both in chromatin and nonchromatin extracts. Besides histones and other known nuclear proteins, trypanosomes chromatin also contains metabolic (mainly from carbohydrate pathway), cytoskeleton and many other proteins with unknown functions. Strikingly, the two parasite forms differ greatly regarding their chromatin-associated factors composition and amount. Although the nucleosome content is the same for both life forms (as seen by MNase digestion), the remaining proteins were much less detected in nonreplicative forms, suggesting that they have a naked chromatin. Proteins associated to DNA proliferation, such as PCNA, RPA, and DNA topoisomerases were exclusively found in the chromatin of replicative stages. On the other hand, the nonreplicative stages have an enrichment of a histone H2B variant. Furthermore, almost 20% of replicative stages chromatin-associated proteins are expressed in nonreplicative forms, but located at nonchromatin space. We identified different classes of proteins including phosphatases and a Ran-binding protein, that may shuttle between chromatin and nonchromatin space during differentiation. Seven proteins, including those with unknown functions, were selected for further validation. We confirmed their location in chromatin and their differential expression, using Western blotting assays and chromatin immunoprecipitation (ChIP). Our results indicate that the replicative state in trypanosomes involves an increase of chromatin associated proteins content. We discuss in details, the qualitative and quantitative implication of this chromatin set in trypanosome chromatin biology. Because trypanosomes are early-branching organisms, this data can boost our understanding of chromatin-associated processes in other cell types.
Collapse
Affiliation(s)
- Teresa Cristina Leandro de Jesus
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil.,§Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo - USP, São Carlos, SP, 13563-120, Brazil
| | - Simone Guedes Calderano
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil.,¶Laboratório de Parasitologia, Instituto Butantan, São Paulo, 05503-900, Brazil
| | - Francisca Nathalia de Luna Vitorino
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Ricardo Pariona Llanos
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Mariana de Camargo Lopes
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Christiane Bezerra de Araújo
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Otavio Henrique Thiemann
- §Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo - USP, São Carlos, SP, 13563-120, Brazil
| | - Marcelo da Silva Reis
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Maria Carolina Elias
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil
| | - Julia Pinheiro Chagas da Cunha
- From the ‡Laboratório Especial de Ciclo Celular - Center of Toxins, Immune-Response and Cell Signaling - CeTICS, Instituto Butantan, São Paulo, SP, 05503-900, Brazil;
| |
Collapse
|
17
|
de Jesus TCL, Nunes VS, Lopes MDC, Martil DE, Iwai LK, Moretti NS, Machado FC, de Lima-Stein ML, Thiemann OH, Elias MC, Janzen C, Schenkman S, da Cunha JPC. Chromatin Proteomics Reveals Variable Histone Modifications during the Life Cycle of Trypanosoma cruzi. J Proteome Res 2016; 15:2039-51. [DOI: 10.1021/acs.jproteome.6b00208] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Teresa Cristina Leandro de Jesus
- Laboratório
Especial de Ciclo Celular, Center of Toxins, Immune Response and Cell
Signaling - CeTICS, Instituto Butantan, São Paulo 05503-900, Brazil
- Departamento
de Física e Informática, Instituto de Física
de São Carlos, Universidade de São Paulo - USP, São Carlos, São Paulo 13563-120, Brazil
| | - Vinícius Santana Nunes
- Departamento
de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil
| | - Mariana de Camargo Lopes
- Laboratório
Especial de Ciclo Celular, Center of Toxins, Immune Response and Cell
Signaling - CeTICS, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Daiana Evelin Martil
- Departamento
de Física e Informática, Instituto de Física
de São Carlos, Universidade de São Paulo - USP, São Carlos, São Paulo 13563-120, Brazil
| | - Leo Kei Iwai
- Laboratório
Especial de Ciclo Celular, Center of Toxins, Immune Response and Cell
Signaling - CeTICS, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Nilmar Silvio Moretti
- Departamento
de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil
| | - Fabrício Castro Machado
- Departamento
de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil
| | - Mariana L. de Lima-Stein
- Departamento
de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil
| | - Otavio Henrique Thiemann
- Departamento
de Física e Informática, Instituto de Física
de São Carlos, Universidade de São Paulo - USP, São Carlos, São Paulo 13563-120, Brazil
| | - Maria Carolina Elias
- Laboratório
Especial de Ciclo Celular, Center of Toxins, Immune Response and Cell
Signaling - CeTICS, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Christian Janzen
- Department
of Cell and Developmental Biology, Theodor-Boveri-Institute at the
Biocenter, University of Würzburg, 97070 Germany
| | - Sergio Schenkman
- Departamento
de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil
| | - Julia Pinheiro Chagas da Cunha
- Laboratório
Especial de Ciclo Celular, Center of Toxins, Immune Response and Cell
Signaling - CeTICS, Instituto Butantan, São Paulo 05503-900, Brazil
| |
Collapse
|
18
|
ElBashir R, Vanselow JT, Kraus A, Janzen CJ, Siegel TN, Schlosser A. Fragment ion patchwork quantification for measuring site-specific acetylation degrees. Anal Chem 2016; 87:9939-45. [PMID: 26335048 DOI: 10.1021/acs.analchem.5b02517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We introduce fragment ion patchwork quantification as a new mass spectrometry-based approach for the highly accurate quantification of site-specific acetylation degrees. This method combines (13)C1-acetyl derivatization on the protein level, proteolysis by low-specificity proteases and quantification on the fragment ion level. Acetylation degrees are determined from the isotope patterns of acetylated b and y ions. We show that this approach allows to determine site-specific acetylation degrees of all lysine residues for all core histones of Trypanosoma brucei. In addition, we demonstrate how this approach can be used to identify substrate sites of histone acetyltransferases.
Collapse
Affiliation(s)
| | | | | | - Christian J Janzen
- Department of Cell & Developmental Biology, Biocenter University of Wuerzburg , Am Hubland, 97074 Wuerzburg, Germany
| | | | | |
Collapse
|
19
|
Lozano-Amado D, Herrera-Solorio AM, Valdés J, Alemán-Lazarini L, Almaraz-Barrera MDJ, Luna-Rivera E, Vargas M, Hernández-Rivas R. Identification of repressive and active epigenetic marks and nuclear bodies in Entamoeba histolytica. Parasit Vectors 2016; 9:19. [PMID: 26767976 PMCID: PMC4712492 DOI: 10.1186/s13071-016-1298-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 01/06/2016] [Indexed: 12/04/2022] Open
Abstract
Background In human hosts, Entamoeba histolytica cysts can develop into trophozoites, suggesting that the life cycle of this parasite are regulated by changes in gene expression. To date, some evidence has suggested that epigenetic mechanisms such as DNA methylation and histone modification are involved in the regulation of gene expression in Entamoeba. Some post–translational modifications (PTMs) at the N-terminus of E. histolytica’s histones have been reported experimentally, including tri-methylation in the lysine 4 of histone H3 (H3K4me3) and dimethylation in the lysine 27 of histone H3 (H3K27me2), dimethylation of arginine 3 (H4R3me2) and the indirect acetylation of histone H4 in the N-terminal region. However, it is not known which residues of histone H4 are subject to acetylation and/or methylation or where in the nucleus these epigenetic marks are located. Methods Histones from trophozoites of E. histolytica were obtained and analyzed by LC-MS/MS. WB assays were performed using antibodies against epigenetic marks (acetylated lysines and methylated arginines). Immunofluorescence assays (IFA) were carried out to determine the distribution of PTMs and the localization of DNA methylation as a heterochromatin marker. Nuclear bodies such as the nucleolus were identified by using antibodies against fibrillarin and nucleolin and speckles by using anti-PRP6 antibody. Results Some new PTMs in histone H4 of E. histolytica, such as the acetylation of lysines 5, 8, 12 and 16 and the monomethylation of arginine 3, were identified by WB. IFA demonstrated that some marks are associated with transcriptional activity (such as acetylation and/or methylation) and that these marks are distributed throughout the E. histolytica nucleus. Staining with antibodies against anti-pan-acetylated lysine H4 histone and 5-methyl cytosine showed that the activation and transcriptional repression marks converge. Additionally, two nuclear bodies, the nucleolus and speckles, were identified in this parasite. Conclusions This study provides the first evidence that the nucleus of E. histolytica is not compartmentalized and contains two nuclear bodies, the nucleolus and speckles, the latter of which was not identified previously. The challenge is now to understand how these epigenetic marks and nuclear bodies work together to regulate gene expression in E. histolytica. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1298-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Daniela Lozano-Amado
- Molecular Biomedicine Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| | - Abril Marcela Herrera-Solorio
- Molecular Biomedicine Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| | - Jesús Valdés
- Biochemistry Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| | - Leticia Alemán-Lazarini
- Molecular Biomedicine Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| | - Ma de Jesús Almaraz-Barrera
- Molecular Biomedicine Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| | - Eva Luna-Rivera
- Molecular Biomedicine Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| | - Miguel Vargas
- Molecular Biomedicine Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| | - Rosaura Hernández-Rivas
- Molecular Biomedicine Department, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (IPN), Av. Instituto Politécnico Nacional # 2508, Apartado postal 14-740,, 07360, D. F. Mexico, México.
| |
Collapse
|
20
|
Molden RC, Bhanu NV, LeRoy G, Arnaudo AM, Garcia BA. Multi-faceted quantitative proteomics analysis of histone H2B isoforms and their modifications. Epigenetics Chromatin 2015; 8:15. [PMID: 25922622 PMCID: PMC4411797 DOI: 10.1186/s13072-015-0006-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/25/2015] [Indexed: 01/01/2023] Open
Abstract
Background Histone isoforms and their post-translational modifications (PTMs) play an important role in the control of many chromatin-related processes including transcription and DNA damage. Variants of histones H2A and H3 have been studied in depth and have been found to have distinct functions. Although 13 somatic histone H2B isoforms have been identified by various biochemical and mass spectrometric (MS) approaches, the distinct roles of these isoforms within human cells are as yet unknown. Here, we have developed quantitative MS techniques to characterize isoform-specific H2B expression across the cell cycle, in differentiated myogenic cells, and in different cancer cell lines to illuminate potential functional roles. Results Using the MS strategies that we developed, we identified differences in H2B isoform levels between different cancer cell types, suggesting cancer or tissue-specific H2B isoform regulation. In particular, we found large variations in the levels of isoforms H2B1B and H2B1M across the panel of cell lines. We also found that, while individual H2B isoforms do not differ in their acetylation levels, trends in the acetylation on all H2B isoforms correlated with acetylation on other histone family members in the cancer cell line panel. We also used the MS strategies to study H2B protein expression across the cell cycle and determined that H2B isoforms that are alternatively spliced to carry a polyadenylation signal rather than the standard histone downstream element are expressed independently of the cell cycle. However, the level of protein produced from the polyadenylated transcripts does not contribute significantly to the total pool of H2B isoforms translated across the cell cycle or in non-cycling myogenic cells. Conclusions Our results show that H2B isoforms are expressed at varying levels in different cells, suggesting isoform-specific, and possibly cell-type-specific, H2B gene regulation. The bottom-up mass spectrometry technique we developed for H2B quantification is compatible with the current standard histone H3 and H4 bottom-up ‘one-pot’ analysis platform so that H2B isoforms and their modifications can be studied in future experiments at the same time as histone H3 and H4 modifications. Therefore, we have expanded the histone landscape that can be interrogated in future experiments. Electronic supplementary material The online version of this article (doi:10.1186/s13072-015-0006-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Rosalynn C Molden
- Department of Chemistry, Princeton University, Princeton, NJ 08544 USA
| | - Natarajan V Bhanu
- Department of Biochemistry and Biophysics, Epigenetics Program, Perelman School of Medicine, University of Pennsylvania, Room 9-124, 3400 Civic Center Blvd., Bldg. 421, Philadelphia, PA 19104 USA
| | - Gary LeRoy
- Department of Chemistry, Princeton University, Princeton, NJ 08544 USA
| | - Anna M Arnaudo
- Department of Chemistry, Princeton University, Princeton, NJ 08544 USA ; Department of Biochemistry and Biophysics, Epigenetics Program, Perelman School of Medicine, University of Pennsylvania, Room 9-124, 3400 Civic Center Blvd., Bldg. 421, Philadelphia, PA 19104 USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Epigenetics Program, Perelman School of Medicine, University of Pennsylvania, Room 9-124, 3400 Civic Center Blvd., Bldg. 421, Philadelphia, PA 19104 USA
| |
Collapse
|
21
|
Denninger V, Rudenko G. FACT plays a major role in histone dynamics affecting VSG expression site control in Trypanosoma brucei. Mol Microbiol 2014; 94:945-62. [PMID: 25266856 PMCID: PMC4625058 DOI: 10.1111/mmi.12812] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2014] [Indexed: 12/21/2022]
Abstract
Chromatin remodelling is involved in the transcriptional regulation of the RNA polymerase I transcribed variant surface glycoprotein (VSG) expression sites (ESs) of Trypanosoma brucei. We show that the T. brucei FACT complex contains the Pob3 and Spt16 subunits, and plays a key role in ES silencing. We see an inverse correlation between transcription and condensed chromatin, whereby FACT knockdown results in ES derepression and more open chromatin around silent ES promoters. Derepressed ESs show increased sensitivity to micrococcal nuclease (MNase) digestion, and a decrease in histones at silent ES promoters but not telomeres. In contrast, FACT knockdown results in more histones at the active ES, correlated with transcription shut-down. ES promoters are derepressed in cells stalled at the G2/M cell cycle stage after knockdown of FACT, but not in G2/M cells stalled after knockdown of cyclin 6. This argues that the observed ES derepression is a direct consequence of histone chaperone activity by FACT at the G2/M cell cycle stage which could affect transcription elongation, rather than an indirect consequence of a cell cycle checkpoint. These experiments highlight the role of the FACT complex in cell cycle-specific chromatin remodelling within VSG ESs.
Collapse
Affiliation(s)
- Viola Denninger
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | | |
Collapse
|
22
|
Depletion of the RNA-binding protein RBP33 results in increased expression of silenced RNA polymerase II transcripts in Trypanosoma brucei. PLoS One 2014; 9:e107608. [PMID: 25215501 PMCID: PMC4162612 DOI: 10.1371/journal.pone.0107608] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 08/18/2014] [Indexed: 12/30/2022] Open
Abstract
We have characterized the RNA-binding protein RBP33 in Trypanosoma brucei, and found that it localizes to the nucleus and is essential for viability. The subset of RNAs bound to RBP33 was determined by immunoprecipitation of ribonucleoprotein complexes followed by deep sequencing. Most RBP33-bound transcripts are predicted to be non-coding. Among these, over one-third are located close to the end of transcriptional units (TUs) or have an antisense orientation within a TU. Depletion of RBP33 resulted in an increase in the level of RNAs derived from regions that are normally silenced, such as strand-switch regions, retroposon and repeat sequences. Our work provides the first example of an RNA-binding protein involved in the regulation of gene silencing in trypanosomes.
Collapse
|
23
|
Maree JP, Patterton HG. The epigenome of Trypanosoma brucei: a regulatory interface to an unconventional transcriptional machine. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:743-50. [PMID: 24942804 DOI: 10.1016/j.bbagrm.2014.05.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 05/09/2014] [Accepted: 05/28/2014] [Indexed: 12/15/2022]
Abstract
The epigenome represents a major regulatory interface to the eukaryotic genome. Nucleosome positions, histone variants, histone modifications and chromatin associated proteins all play a role in the epigenetic regulation of DNA function. Trypanosomes, an ancient branch of the eukaryotic evolutionary lineage, exhibit some highly unusual transcriptional features, including the arrangement of functionally unrelated genes in large, polymerase II transcribed polycistronic transcription units, often exceeding hundreds of kilobases in size. It is generally believed that transcription initiation plays a minor role in regulating the transcript level of genes in trypanosomes, which are mainly regulated post-transcriptionally. Recent advances have revealed that epigenetic mechanisms play an essential role in the transcriptional regulation of Trypanosoma brucei. This suggested that the modulation of gene activity, particularly that of pol I transcribed genes, is, indeed, an important control mechanism, and that the epigenome is critical in regulating gene expression programs that allow the successful migration of this parasite between hosts, as well as the continuous evasion of the immune system in mammalian hosts. A wide range of epigenetic signals, readers, writers and erasers have been identified in trypanosomes, some of which have been mapped to essential genetic functions. Some epigenetic mechanisms have also been observed to be unique to trypanosomes. We review recent advances in our understanding of epigenetic control mechanisms in T. brucei, the causative agent of African sleeping sickness, and highlight the utility of epigenetic targets in the possible development of new therapies for human African trypanosomiasis.
Collapse
Affiliation(s)
- Johannes P Maree
- Advanced Biomolecular Research Cluster, University of the Free State, PO Box 339, Bloemfontein 9332, South Africa
| | - Hugh-G Patterton
- Advanced Biomolecular Research Cluster, University of the Free State, PO Box 339, Bloemfontein 9332, South Africa.
| |
Collapse
|
24
|
Vanagas L, Jeffers V, Bogado SS, Dalmasso MC, Sullivan WJ, Angel SO. Toxoplasma histone acetylation remodelers as novel drug targets. Expert Rev Anti Infect Ther 2013. [PMID: 23199404 DOI: 10.1586/eri.12.100] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Toxoplasma gondii is a leading cause of neurological birth defects and a serious opportunistic pathogen. The authors and others have found that Toxoplasma uses a unique nucleosome composition supporting a fine gene regulation together with other factors. Post-translational modifications in histones facilitate the establishment of a global chromatin environment and orchestrate DNA-related biological processes. Histone acetylation is one of the most prominent post-translational modifications influencing gene expression. Histone acetyltransferases and histone deacetylases have been intensively studied as potential drug targets. In particular, histone deacetylase inhibitors have activity against apicomplexan parasites, underscoring their potential as a new class of antiparasitic compounds. In this review, we summarize what is known about Toxoplasma histone acetyltransferases and histone deacetylases, and discuss the inhibitors studied to date. Finally, the authors discuss the distinct possibility that the unique nucleosome composition of Toxoplasma, which harbors a nonconserved H2Bv variant histone, might be targeted in novel therapeutics directed against this parasite.
Collapse
Affiliation(s)
- Laura Vanagas
- Laboratorio de Parasitología Molecular, IIB-INTECH, CONICET-UNSAM, Av. Intendente Marino Km. 8.2, C.C 164, (B7130IIWA), Chascomús, Prov. Buenos Aires, Argentina.
| | | | | | | | | | | |
Collapse
|
25
|
Abstract
Faithful transmission of genetic material is essential for the survival of all organisms. Eukaryotic chromosome segregation is driven by the kinetochore that assembles onto centromeric DNA to capture spindle microtubules and govern the movement of chromosomes. Its molecular mechanism has been actively studied in conventional model eukaryotes, such as yeasts, worms, flies and human. However, these organisms are closely related in the evolutionary time scale and it therefore remains unclear whether all eukaryotes use a similar mechanism. The evolutionary origins of the segregation apparatus also remain enigmatic. To gain insights into these questions, it is critical to perform comparative studies. Here, we review our current understanding of the mitotic mechanism in Trypanosoma brucei, an experimentally tractable kinetoplastid parasite that branched early in eukaryotic history. No canonical kinetochore component has been identified, and the design principle of kinetochores might be fundamentally different in kinetoplastids. Furthermore, these organisms do not appear to possess a functional spindle checkpoint that monitors kinetochore-microtubule attachments. With these unique features and the long evolutionary distance from other eukaryotes, understanding the mechanism of chromosome segregation in T. brucei should reveal fundamental requirements for the eukaryotic segregation machinery, and may also provide hints about the origin and evolution of the segregation apparatus.
Collapse
Affiliation(s)
- Bungo Akiyoshi
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | | |
Collapse
|
26
|
Petter M, Selvarajah SA, Lee CC, Chin WH, Gupta AP, Bozdech Z, Brown GV, Duffy MF. H2A.Z and H2B.Z double-variant nucleosomes define intergenic regions and dynamically occupy var gene promoters in the malaria parasite Plasmodium falciparum. Mol Microbiol 2013; 87:1167-82. [PMID: 23373537 DOI: 10.1111/mmi.12154] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2013] [Indexed: 12/15/2022]
Abstract
Histone variants are important components of eukaryotic chromatin and can alter chromatin structure to confer specialized functions. H2B variant histones are rare in nature but have evolved independently in the phyla Apicomplexa and Trypanasomatida. Here, we investigate the apicomplexan-specific Plasmodium falciparum histone variant Pf H2B.Z and show that within nucleosomes Pf H2B.Z dimerizes with the H2A variant Pf H2A.Z and that Pf H2B.Z and Pf H2A.Z occupancy correlates in the subset of genes examined. These double-variant nucleosomes also carry common markers of euchromatin like H3K4me3 and histone acetylation. Pf H2B.Z levels are elevated in intergenic regions across the genome, except in the var multigene family, where Pf H2A.Z/Pf H2B.Z double-variant nucleosomes are only enriched in the promoter of the single active var copy and this enrichment is developmentally regulated. Importantly, this pattern seems to be specific for var genes and does not apply to other heterochromatic gene families involved in red blood cell invasion which are also subject to clonal expression. Thus, Pf H2A.Z/Pf H2B.Z double-variant nucleosomes appear to have a highly specific function in the regulation of P. falciparum virulence.
Collapse
Affiliation(s)
- Michaela Petter
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Hoeijmakers WAM, Salcedo-Amaya AM, Smits AH, Françoijs KJ, Treeck M, Gilberger TW, Stunnenberg HG, Bártfai R. H2A.Z/H2B.Z double-variant nucleosomes inhabit the AT-rich promoter regions of the Plasmodium falciparum genome. Mol Microbiol 2013; 87:1061-73. [PMID: 23320541 PMCID: PMC3594968 DOI: 10.1111/mmi.12151] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2013] [Indexed: 02/06/2023]
Abstract
Histone variants are key components of the epigenetic code and evolved to perform specific functions in transcriptional regulation, DNA repair, chromosome segregation and other fundamental processes. Although variants for histone H2A and H3 are found throughout the eukaryotic kingdom, variants of histone H2B and H4 are rarely encountered. H2B.Z is one of those rare H2B variants and is apicomplexan-specific. Here we show that in Plasmodium falciparum H2B.Z localizes to euchromatic intergenic regions throughout intraerythrocytic development and together with H2A.Z forms a double-variant nucleosome subtype. These nucleosomes are enriched in promoters over 3′ intergenic regions and their occupancy generally correlates with the strength of the promoter, but not with its temporal activity. Remarkably, H2B.Z occupancy levels exhibit a clear correlation with the base-composition of the underlying DNA, raising the intriguing possibility that the extreme AT content of the intergenic regions within the Plasmodium genome might be instructive for histone variant deposition. In summary, our data show that the H2A.Z/H2B.Z double-variant nucleosome demarcates putative regulatory regions of the P. falciparum epigenome and likely provides a scaffold for dynamic regulation of gene expression in this deadly human pathogen.
Collapse
Affiliation(s)
- Wieteke A M Hoeijmakers
- Department of Molecular Biology, Radboud University, Nijmegen Centre for Molecular Life Sciences, Nijmegen 6525GA, the Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Dynamics of modeled oligonucleosomes and the role of histone variant proteins in nucleosome organization. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 90:119-49. [PMID: 23582203 DOI: 10.1016/b978-0-12-410523-2.00004-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Elucidation of the structural dynamics of a nucleosome is of primary importance for understanding the molecular mechanisms that control the nucleosomal positioning. The presence of variant histone proteins in the nucleosome core raises the functional diversity of the nucleosomes in gene regulation and has the profound epigenetic consequences of great importance for understanding the fundamental issues like the assembly of variant nucleosomes, chromatin remodeling, histone posttranslational modifications, etc. Here, we report our observation of the dominant mechanisms of relaxation motions of the oligonucleosomes such as dimer, trimer, and tetramer (in the beads on a string model) with conventional core histones and role of variant histone H2A.Z in the chromatin dynamics using normal mode analysis. Analysis of the directionality of the global dynamics of the oligonucleosome reveals (i) the in-planar stretching as well as out-of-planar bending motions as the relaxation mechanisms of the oligonucleosome and (ii) the freedom of the individual nucleosome in expressing the combination of the above-mentioned motions as the global mode of dynamics. The highly dynamic N-termini of H3 and (H2A.Z-H2B) dimer evidence their participation in the transcriptionally active state. The key role of variant H2A.Z histone as a major source of vibrant motions via weaker intra- and intermolecular correlations is emphasized in this chapter.
Collapse
|
29
|
Bönisch C, Hake SB. Histone H2A variants in nucleosomes and chromatin: more or less stable? Nucleic Acids Res 2012; 40:10719-41. [PMID: 23002134 PMCID: PMC3510494 DOI: 10.1093/nar/gks865] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
In eukaryotes, DNA is organized together with histones and non-histone proteins into a highly complex nucleoprotein structure called chromatin, with the nucleosome as its monomeric subunit. Various interconnected mechanisms regulate DNA accessibility, including replacement of canonical histones with specialized histone variants. Histone variant incorporation can lead to profound chromatin structure alterations thereby influencing a multitude of biological processes ranging from transcriptional regulation to genome stability. Among core histones, the H2A family exhibits highest sequence divergence, resulting in the largest number of variants known. Strikingly, H2A variants differ mostly in their C-terminus, including the docking domain, strategically placed at the DNA entry/exit site and implicated in interactions with the (H3–H4)2-tetramer within the nucleosome and in the L1 loop, the interaction interface of H2A–H2B dimers. Moreover, the acidic patch, important for internucleosomal contacts and higher-order chromatin structure, is altered between different H2A variants. Consequently, H2A variant incorporation has the potential to strongly regulate DNA organization on several levels resulting in meaningful biological output. Here, we review experimental evidence pinpointing towards outstanding roles of these highly variable regions of H2A family members, docking domain, L1 loop and acidic patch, and close by discussing their influence on nucleosome and higher-order chromatin structure and stability.
Collapse
Affiliation(s)
- Clemens Bönisch
- Department of Molecular Biology, Center for Integrated Protein Science Munich, Adolf-Butenandt-Institute, Ludwig-Maximilians-University Munich, 80336 Munich, Germany.
| | | |
Collapse
|
30
|
Tschudi C, Shi H, Franklin JB, Ullu E. Small interfering RNA-producing loci in the ancient parasitic eukaryote Trypanosoma brucei. BMC Genomics 2012; 13:427. [PMID: 22925482 PMCID: PMC3447711 DOI: 10.1186/1471-2164-13-427] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 08/24/2012] [Indexed: 01/24/2023] Open
Abstract
Background At the core of the RNA interference (RNAi) pathway in Trypanosoma brucei is a single Argonaute protein, TbAGO1, with an established role in controlling retroposon and repeat transcripts. Recent evidence from higher eukaryotes suggests that a variety of genomic sequences with the potential to produce double-stranded RNA are sources for small interfering RNAs (siRNAs). Results To test whether such endogenous siRNAs are present in T. brucei and to probe the individual role of the two Dicer-like enzymes, we affinity purified TbAGO1 from wild-type procyclic trypanosomes, as well as from cells deficient in the cytoplasmic (TbDCL1) or nuclear (TbDCL2) Dicer, and subjected the bound RNAs to Illumina high-throughput sequencing. In wild-type cells the majority of reads originated from two classes of retroposons. We also considerably expanded the repertoire of trypanosome siRNAs to encompass a family of 147-bp satellite-like repeats, many of the regions where RNA polymerase II transcription converges, large inverted repeats and two pseudogenes. Production of these newly described siRNAs is strictly dependent on the nuclear DCL2. Notably, our data indicate that putative centromeric regions, excluding the CIR147 repeats, are not a significant source for endogenous siRNAs. Conclusions Our data suggest that endogenous RNAi targets may be as evolutionarily old as the mechanism itself.
Collapse
Affiliation(s)
- Christian Tschudi
- Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT 06536, USA
| | | | | | | |
Collapse
|
31
|
Talbert PB, Ahmad K, Almouzni G, Ausió J, Berger F, Bhalla PL, Bonner WM, Cande WZ, Chadwick BP, Chan SWL, Cross GAM, Cui L, Dimitrov SI, Doenecke D, Eirin-López JM, Gorovsky MA, Hake SB, Hamkalo BA, Holec S, Jacobsen SE, Kamieniarz K, Khochbin S, Ladurner AG, Landsman D, Latham JA, Loppin B, Malik HS, Marzluff WF, Pehrson JR, Postberg J, Schneider R, Singh MB, Smith MM, Thompson E, Torres-Padilla ME, Tremethick DJ, Turner BM, Waterborg JH, Wollmann H, Yelagandula R, Zhu B, Henikoff S. A unified phylogeny-based nomenclature for histone variants. Epigenetics Chromatin 2012; 5:7. [PMID: 22650316 PMCID: PMC3380720 DOI: 10.1186/1756-8935-5-7] [Citation(s) in RCA: 228] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Accepted: 05/31/2012] [Indexed: 12/02/2022] Open
Abstract
Histone variants are non-allelic protein isoforms that play key roles in diversifying chromatin structure. The known number of such variants has greatly increased in recent years, but the lack of naming conventions for them has led to a variety of naming styles, multiple synonyms and misleading homographs that obscure variant relationships and complicate database searches. We propose here a unified nomenclature for variants of all five classes of histones that uses consistent but flexible naming conventions to produce names that are informative and readily searchable. The nomenclature builds on historical usage and incorporates phylogenetic relationships, which are strong predictors of structure and function. A key feature is the consistent use of punctuation to represent phylogenetic divergence, making explicit the relationships among variant subtypes that have previously been implicit or unclear. We recommend that by default new histone variants be named with organism-specific paralog-number suffixes that lack phylogenetic implication, while letter suffixes be reserved for structurally distinct clades of variants. For clarity and searchability, we encourage the use of descriptors that are separate from the phylogeny-based variant name to indicate developmental and other properties of variants that may be independent of structure.
Collapse
Affiliation(s)
- Paul B Talbert
- Howard Hughes Medical Institute, Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Chromatin modifications, epigenetics, and how protozoan parasites regulate their lives. Trends Parasitol 2012; 28:202-13. [PMID: 22480826 DOI: 10.1016/j.pt.2012.02.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 02/21/2012] [Accepted: 02/29/2012] [Indexed: 12/19/2022]
Abstract
Chromatin structure plays a vital role in epigenetic regulation of protozoan parasite gene expression. Epigenetic gene regulation impacts upon parasite virulence, differentiation and cell-cycle control. Recent work in many laboratories has elucidated the functions of proteins that regulate parasite gene expression by chemical modification of constituent nucleosomes. A major focus of investigation has been the characterization of post-translational modifications (PTMs) of histones and the identification of the enzymes responsible. Despite conserved features and specificity common to all eukaryotes, parasite enzymes involved in chromatin modification have unique functions that regulate unique aspects of parasite biology.
Collapse
|
33
|
Moosmann A, Campsteijn C, Jansen PW, Nasrallah C, Raasholm M, Stunnenberg HG, Thompson EM. Histone variant innovation in a rapidly evolving chordate lineage. BMC Evol Biol 2011; 11:208. [PMID: 21756361 PMCID: PMC3156773 DOI: 10.1186/1471-2148-11-208] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 07/15/2011] [Indexed: 01/04/2023] Open
Abstract
Background Histone variants alter the composition of nucleosomes and play crucial roles in transcription, chromosome segregation, DNA repair, and sperm compaction. Modification of metazoan histone variant lineages occurs on a background of genome architecture that shows global similarities from sponges to vertebrates, but the urochordate, Oikopleura dioica, a member of the sister group to vertebrates, exhibits profound modification of this ancestral architecture. Results We show that a histone complement of 47 gene loci encodes 31 histone variants, grouped in distinct sets of developmental expression profiles throughout the life cycle. A particularly diverse array of 15 male-specific histone variants was uncovered, including a testes-specific H4t, the first metazoan H4 sequence variant reported. Universal histone variants H3.3, CenH3, and H2A.Z are present but O. dioica lacks homologs of macroH2A and H2AX. The genome encodes many H2A and H2B variants and the repertoire of H2A.Z isoforms is expanded through alternative splicing, incrementally regulating the number of acetylatable lysine residues in the functionally important N-terminal "charge patch". Mass spectrometry identified 40 acetylation, methylation and ubiquitylation posttranslational modifications (PTMs) and showed that hallmark PTMs of "active" and "repressive" chromatin were present in O. dioica. No obvious reduction in silent heterochromatic marks was observed despite high gene density in this extraordinarily compacted chordate genome. Conclusions These results show that histone gene complements and their organization differ considerably even over modest phylogenetic distances. Substantial innovation among all core and linker histone variants has evolved in concert with adaptation of specific life history traits in this rapidly evolving chordate lineage.
Collapse
|
34
|
Ersfeld K. Nuclear architecture, genome and chromatin organisation in Trypanosoma brucei. Res Microbiol 2011; 162:626-36. [PMID: 21392575 DOI: 10.1016/j.resmic.2011.01.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 01/29/2011] [Indexed: 11/29/2022]
Abstract
The nucleus of the human pathogen Trypanosoma brucei not only has unusual chromosomal composition, characterised by the presence of megabase, intermediate and minichromosomes, but also chromosome and gene organisation that is unique amongst eukaryotes. Here I provide an overview of current knowledge of nuclear structure, chromatin organisation and chromosome dynamics during interphase and mitosis. New technologies such as chromatin immunoprecipitation, in combination with new generation sequencing and proteomic analysis of subnuclear fractions, have led to novel insights into the organisation of the nucleus and chromatin. In particular, we are beginning to understand how universal mechanisms of chromatin modifications and nuclear position effects are deployed for parasite-specific functions and are centrally involved in genomic organisation and transcriptional regulation. These advances also have a major impact on progress in understanding the molecular basis of antigenic variation.
Collapse
Affiliation(s)
- Klaus Ersfeld
- Department of Biological Sciences and Hull York Medical School, University of Hull, Hull HU6 7RX, UK.
| |
Collapse
|
35
|
Abstract
Trypanosomes are a group of protozoan eukaryotes, many of which are major parasites of humans and livestock. The genomes of trypanosomes and their modes of gene expression differ in several important aspects from those of other eukaryotic model organisms. Protein-coding genes are organized in large directional gene clusters on a genome-wide scale, and their polycistronic transcription is not generally regulated at initiation. Transcripts from these polycistrons are processed by global trans-splicing of pre-mRNA. Furthermore, in African trypanosomes, some protein-coding genes are transcribed by a multifunctional RNA polymerase I from a specialized extranucleolar compartment. The primary DNA sequence of the trypanosome genomes and their cellular organization have usually been treated as separate entities. However, it is becoming increasingly clear that in order to understand how a genome functions in a living cell, we will need to unravel how the one-dimensional genomic sequence and its trans-acting factors are arranged in the three-dimensional space of the eukaryotic nucleus. Understanding this cell biology of the genome will be crucial if we are to elucidate the genetic control mechanisms of parasitism. Here, we integrate the concepts of nuclear architecture, deduced largely from studies of yeast and mammalian nuclei, with recent developments in our knowledge of the trypanosome genome, gene expression, and nuclear organization. We also compare this nuclear organization to those in other systems in order to shed light on the evolution of nuclear architecture in eukaryotes.
Collapse
|
36
|
Expression of P. falciparum var genes involves exchange of the histone variant H2A.Z at the promoter. PLoS Pathog 2011; 7:e1001292. [PMID: 21379342 PMCID: PMC3040674 DOI: 10.1371/journal.ppat.1001292] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 01/12/2011] [Indexed: 12/31/2022] Open
Abstract
Plasmodium falciparum employs antigenic variation to evade the human immune response by switching the expression of different variant surface antigens encoded by the var gene family. Epigenetic mechanisms including histone modifications and sub-nuclear compartmentalization contribute to transcriptional regulation in the malaria parasite, in particular to control antigenic variation. Another mechanism of epigenetic control is the exchange of canonical histones with alternative variants to generate functionally specialized chromatin domains. Here we demonstrate that the alternative histone PfH2A.Z is associated with the epigenetic regulation of var genes. In many eukaryotic organisms the histone variant H2A.Z mediates an open chromatin structure at promoters and facilitates diverse levels of regulation, including transcriptional activation. Throughout the asexual, intraerythrocytic lifecycle of P. falciparum we found that the P. falciparum ortholog of H2A.Z (PfH2A.Z) colocalizes with histone modifications that are characteristic of transcriptionally-permissive euchromatin, but not with markers of heterochromatin. Consistent with this finding, antibodies to PfH2A.Z co-precipitate the permissive modification H3K4me3. By chromatin-immunoprecipitation we show that PfH2A.Z is enriched in nucleosomes around the transcription start site (TSS) in both transcriptionally active and silent stage-specific genes. In var genes, however, PfH2A.Z is enriched at the TSS only during active transcription in ring stage parasites. Thus, in contrast to other genes, temporal var gene regulation involves histone variant exchange at promoter nucleosomes. Sir2 histone deacetylases are important for var gene silencing and their yeast ortholog antagonises H2A.Z function in subtelomeric yeast genes. In immature P. falciparum parasites lacking Sir2A or Sir2B high var transcription levels correlate with enrichment of PfH2A.Z at the TSS. As Sir2A knock out parasites mature the var genes are silenced, but PfH2A.Z remains enriched at the TSS of var genes; in contrast, PfH2A.Z is lost from the TSS of de-repressed var genes in mature Sir2B knock out parasites. This result indicates that PfH2A.Z occupancy at the active var promoter is antagonized by PfSir2A during the intraerythrocytic life cycle. We conclude that PfH2A.Z contributes to the nucleosome architecture at promoters and is regulated dynamically in active var genes. Plasmodium falciparum is a protist parasite that causes malaria and kills more than 800,000 people per year. The parasite escapes from the human immune response by antigenic variation through switching between expression of different var genes. These encode different variant antigens that are expressed on the surface of the infected erythrocyte and mediate pathogenic adhesion of the infected erythrocytes to host receptors. Understanding how this process is regulated may lead to the identification of factors that are essential for immune evasion and that could represent novel drug targets. Here, we have identified the parasite's histone variant PfH2A.Z as a novel contributor to the transcriptional regulation of antigenic variation. PfH2A.Z is enriched in the promoter of many genes, but enrichment correlates with gene expression only in var genes. Furthermore we show that PfH2A.Z enrichment in var promoters is antagonised by the var gene silencing factor PfSir2A. These findings further extend our knowledge of the complex mechanisms regulating gene expression in P. falciparum.
Collapse
|
37
|
H2A.Z demarcates intergenic regions of the plasmodium falciparum epigenome that are dynamically marked by H3K9ac and H3K4me3. PLoS Pathog 2010; 6:e1001223. [PMID: 21187892 PMCID: PMC3002978 DOI: 10.1371/journal.ppat.1001223] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 11/10/2010] [Indexed: 01/18/2023] Open
Abstract
Epigenetic regulatory mechanisms and their enzymes are promising targets for malaria therapeutic intervention; however, the epigenetic component of gene expression in P. falciparum is poorly understood. Dynamic or stable association of epigenetic marks with genomic features provides important clues about their function and helps to understand how histone variants/modifications are used for indexing the Plasmodium epigenome. We describe a novel, linear amplification method for next-generation sequencing (NGS) that allows unbiased analysis of the extremely AT-rich Plasmodium genome. We used this method for high resolution, genome-wide analysis of a histone H2A variant, H2A.Z and two histone H3 marks throughout parasite intraerythrocytic development. Unlike in other organisms, H2A.Z is a constant, ubiquitous feature of euchromatic intergenic regions throughout the intraerythrocytic cycle. The almost perfect colocalisation of H2A.Z with H3K9ac and H3K4me3 suggests that these marks are preferentially deposited on H2A.Z-containing nucleosomes. By performing RNA-seq on 8 time-points, we show that acetylation of H3K9 at promoter regions correlates very well with the transcriptional status whereas H3K4me3 appears to have stage-specific regulation, being low at early stages, peaking at trophozoite stage, but does not closely follow changes in gene expression. Our improved NGS library preparation procedure provides a foundation to exploit the malaria epigenome in detail. Furthermore, our findings place H2A.Z at the cradle of P. falciparum epigenetic regulation by stably defining intergenic regions and providing a platform for dynamic assembly of epigenetic and other transcription related complexes. Plasmodium falciparum is a unicellular pathogen that is responsible for the most severe form of malaria. Similar to other eukaryotic organisms, its genome is organized into chromosomes by proteins called histones. Modification or replacement of these histones has marked effects on the packaging grade of DNA and instructs the recruitment of protein complexes, thereby regulating essential cellular processes such as gene expression and replication. Here we unveil the genome-wide localization of two histone H3 modifications (K9ac/K4me3) and a histone variant, H2A.Z, during development of the parasite in the human red blood cells. We find that all three epigenetic features are predominantly present in intergenic regions of the P. falciparum genome, suggesting an interconnecting role in regulation of gene expression. H2A.Z levels appear to be largely invariable throughout intraerythrocytic development while placement/removal of the histone marks is dynamic with H3K9ac and H3K4me3 being transcription-coupled and stage-specific, respectively. These observations support a model in which H2A.Z-containing nucleosomes serve to demarcate regulatory regions in the parasite's genome and promote transcription initiation by guiding chromatin modifying and transcription initiating complexes. The findings and methodological developments presented in this paper provide a cornerstone for future epigenome research in eukaryotic pathogens and vital information to understand and to interfere with parasite development and survival.
Collapse
|
38
|
Chromatin-mediated epigenetic regulation in the malaria parasite Plasmodium falciparum. EUKARYOTIC CELL 2010; 9:1138-49. [PMID: 20453074 DOI: 10.1128/ec.00036-10] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Malaria is a major public health problem in many developing countries, with the malignant tertian parasite Plasmodium falciparum causing the most malaria-associated mortality. Extensive research, especially with the advancement of genomics and transfection tools, has highlighted the fundamental importance of chromatin-mediated gene regulation in the developmental program of this early-branching eukaryote. The Plasmodium parasite genomes reveal the existence of both canonical and variant histones that make up the nucleosomes, as well as a full collection of conserved enzymes for chromatin remodeling and histone posttranslational modifications (PTMs). Recent studies have identified a wide array of both conserved and novel histone PTMs in P. falciparum, indicating the presence of a complex and divergent "histone code." Genome-wide analysis has begun to decipher the nucleosome landscape and histone modifications associated with the dynamic organization of chromatin structures during the parasite's life cycle. Focused studies on malaria-specific phenomena such as antigenic variation and red cell invasion pathways shed further light on the involvement of epigenetic mechanisms in these processes. Here we review our current understanding of chromatin-mediated gene regulation in malaria parasites, with specific reference to exemplar studies on antigenic variation and host cell invasion.
Collapse
|
39
|
Wright JR, Siegel TN, Cross GAM. Histone H3 trimethylated at lysine 4 is enriched at probable transcription start sites in Trypanosoma brucei. Mol Biochem Parasitol 2010; 172:141-4. [PMID: 20347883 DOI: 10.1016/j.molbiopara.2010.03.013] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 03/19/2010] [Indexed: 10/19/2022]
Abstract
Recent studies have identified histone modifications and suggested a role for epigenetic gene regulation in Trypanosoma brucei. The histone modification H4K10ac and histone variants H2AZ and H2BV localize to probable sites of transcription initiation. Although all T. brucei histones have very evolutionarily divergent N-terminal tails, histone H3 shows conservation with other eukaryotic organisms in 6 of 8 amino acids encompassing lysine 4. Tri-methylation of H3K4 is generally associated with transcription. We therefore generated a specific antibody to T. brucei H3K4me3 and performed chromosome immunoprecipitation and high-throughput sequencing. We show that H3K4me3 is enriched at the start of polycistronic transcription units at divergent strand-switch regions and at other sites of RNA polymerase II transcription reinitiation. H3K4me3 largely co-localizes with H4K10ac, but with a skew towards the upstream side of the H4K10ac peak, suggesting that it is a component of specific nucleosomes that play a role in Pol II transcription initiation.
Collapse
Affiliation(s)
- Jessica R Wright
- Laboratory of Molecular Parasitology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | | | | |
Collapse
|
40
|
González-Romero R, Rivera-Casas C, Ausió J, Méndez J, Eirín-López JM. Birth-and-death long-term evolution promotes histone H2B variant diversification in the male germinal cell line. Mol Biol Evol 2010; 27:1802-12. [PMID: 20194426 DOI: 10.1093/molbev/msq058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The rich diversity within each of the five histone families (H1, H2A, H2B, H3, and H4) can hardly be reconciled with the notion of homogenizing evolution. The prevalence of birth-and-death long-term evolution over concerted evolution has already been demonstrated in the linker histone H1 family as well as for the H2A, H3, and H4 core histone families. However, information about histone H2B is lacking. In the present work, we have analyzed the diversity of the members of this histone family across different eukaryotic genomes and have characterized the mechanisms involved in their long-term evolution. Our results reveal that, quite in contrast with other histones, H2B variants are subject to a very rapid process of diversification that primarily affects the male germinal cell lineage and involves their functional specialization probably as a consequence of neofunctionalization and subfunctionalization events after gene duplication. The overall parallelism observed between the molecular phylogenies and the relationships among the electrostatic potentials of the different variants suggests that the latter may have played a major structural selective constraint during H2B evolution. It thus seems that the reorganization of chromatin structure during spermiogenesis might have affected the evolutionary constraints driving histone H2B evolution, leading to an increase in diversity.
Collapse
Affiliation(s)
- Rodrigo González-Romero
- XENOMAR-CHROMEVOL Group, Departamento de Biología Celular y Molecular, Universidade da Coruña, Coruña, Spain
| | | | | | | | | |
Collapse
|
41
|
Gene expression in trypanosomatid parasites. J Biomed Biotechnol 2010; 2010:525241. [PMID: 20169133 PMCID: PMC2821653 DOI: 10.1155/2010/525241] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 11/04/2009] [Indexed: 12/21/2022] Open
Abstract
The parasites Leishmania spp., Trypanosoma brucei, and Trypanosoma cruzi are the trypanosomatid protozoa that cause the deadly human diseases leishmaniasis, African sleeping sickness, and Chagas disease, respectively. These organisms possess unique mechanisms for gene expression such as constitutive polycistronic transcription of protein-coding genes and trans-splicing. Little is known about either the DNA sequences or the proteins that are involved in the initiation and termination of transcription in trypanosomatids. In silico analyses of the genome databases of these parasites led to the identification of a small number of proteins involved in gene expression. However, functional studies have revealed that trypanosomatids have more general transcription factors than originally estimated. Many posttranslational histone modifications, histone variants, and chromatin modifying enzymes have been identified in trypanosomatids, and recent genome-wide studies showed that epigenetic regulation might play a very important role in gene expression in this group of parasites. Here, we review and comment on the most recent findings related to transcription initiation and termination in trypanosomatid protozoa.
Collapse
|
42
|
Abstract
RNA interference (RNAi) is defined as the mechanism through which double-stranded RNA (dsRNA) triggers degradation of homologous transcripts. Besides providing an invaluable tool to downregulate gene expression in a variety of organisms, it is now evident that RNAi acts beyond the cytoplasm and is involved in a variety of gene-silencing phenomena in the nucleus. In the present work we review the current status of the knowledge about RNAi in protozoan parasites that belong to the Trypanosoma genus and have medical relevance. While RNAi was first discovered in Trypanosoma brucei, it became evident that other members of the same genus of organisms, namely Trypanosoma cruzi, does not possess RNAi, probably due to the lack of Ago protein analogs in their genomes. We will discuss the genome organization of Trypanosoma cruzi and propose that the absence of both RNAi and gene promoters is symptomatic of alternative epigenetic controls in this parasite orchestrated by parasite-host interactions. Whereas in Trypanosoma brucei, RNAi and other epigenetic controls dictate alternative transcriptional programs critical for virulence.
Collapse
|
43
|
Nucleosomes are depleted at the VSG expression site transcribed by RNA polymerase I in African trypanosomes. EUKARYOTIC CELL 2009; 9:148-54. [PMID: 19915072 DOI: 10.1128/ec.00282-09] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In most eukaryotes, RNA polymerase I (Pol I) exclusively transcribes long arrays of identical rRNA genes (ribosomal DNA [rDNA]). African trypanosomes have the unique property of using Pol I to also transcribe the variant surface glycoprotein VSG genes. VSGs are important virulence factors because their switching allows trypanosomes to escape the host immune system, a mechanism known as antigenic variation. Only one VSG is transcribed at a time from one of 15 bloodstream-form expression sites (BESs). Although it is clear that switching among BESs does not involve DNA rearrangements and that regulation is probably epigenetic, it remains unknown why BESs are transcribed by Pol I and what roles are played by chromatin structure and histone modifications. Using chromatin immunoprecipitation, micrococcal nuclease digestion, and chromatin fractionation, we observed that there are fewer nucleosomes at the active BES and that these are irregularly spaced compared to silent BESs. rDNA coding regions are also depleted of nucleosomes, relative to the rDNA spacer. In contrast, genes transcribed by Pol II are organized in a more compact, regularly spaced, nucleosomal structure. These observations provide new insight on antigenic variation by showing that chromatin remodeling is an intrinsic feature of BES regulation.
Collapse
|
44
|
Elias MC, Nardelli SC, Schenkman S. Chromatin and nuclear organization in Trypanosoma cruzi. Future Microbiol 2009; 4:1065-74. [DOI: 10.2217/fmb.09.74] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A total of 100 years have passed since the discovery of the protozoan Trypanosoma cruzi, the etiologic agent of Chagas’ disease. Since its discovery, the molecular and cellular biology of this early divergent eukaryote, as well as its interactions with the mammalian and insect hosts, has progressed substantially. It is now clear that this parasite presents unique mechanisms controlling gene expression, DNA replication, cell cycle and differentiation, generating several morphological forms that are adapted to survive in different hosts. In recent years, the relationship between the chromatin structure and nuclear organization with the unusual transcription, splicing, DNA replication and DNA repair mechanisms have been investigated in T. cruzi. This article reviews the relevant aspects of these mechanisms in relation to chromatin and nuclear organization.
Collapse
Affiliation(s)
| | - Sheila Cristina Nardelli
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, R. Botucatu 862 8a, 04023-062 São Paulo, Brazil
| | - Sergio Schenkman
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, R. Botucatu 862 8a, 04023-062 São Paulo, Brazil
| |
Collapse
|
45
|
Toxoplasma H2A variants reveal novel insights into nucleosome composition and functions for this histone family. J Mol Biol 2009; 392:33-47. [PMID: 19607843 DOI: 10.1016/j.jmb.2009.07.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 06/26/2009] [Accepted: 07/07/2009] [Indexed: 12/31/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite. Toxoplasmosis is incurable because of its ability to differentiate from the rapidly replicating tachyzoite stage into a latent cyst form (bradyzoite stage). Gene regulation pertinent to Toxoplasma differentiation involves histone modification, but very little is known about the histone proteins in this early branching eukaryote. Here, we report the characterization of three H2A histones, variants H2AX and H2AZ, and a canonical H2A1. H2AZ is the minor parasite H2A member. H2A1 and H2AX both have an SQ motif, but only H2AX has a complete SQ(E/D)varphi (where varphi denotes a hydrophobic residue) known to be phosphorylated in response to DNA damage. We show that a novel H2B variant interacts with H2AZ and H2A1 but not with H2AX. Chromatin immunoprecipitation (ChIP) revealed that H2AZ and H2Bv are enriched at active genes while H2AX is enriched at repressed genes as well as the silent TgIRE repeat element. During DNA damage, we detected an increase in H2AX phosphorylation as well as increases in h2a1 and h2ax transcription. We found that expression of h2ax, but not h2a1 or h2az, increases in bradyzoites generated in vitro. Similar analysis performed on mature bradyzoites generated in vivo, which are arrested in G0, showed that h2az and h2ax are expressed but h2a1 is not, consistent with the idea that h2a1 is the canonical histone orthologue in the parasite. The increase of H2AX, which localizes to silenced areas during bradyzoite differentiation, is consistent with the quiescent nature of this stage of the life cycle. Our results indicate that the early-branching eukaryotic parasite Toxoplasma contains nucleosomes of novel composition, which is likely to impact multiple facets of parasite biology, including the clinically important process of bradyzoite differentiation.
Collapse
|
46
|
Abstract
Epigenetic regulation is important in many facets of eukaryotic biology. Recent work has suggested that the basic mechanisms underlying epigenetic regulation extend to eukaryotic parasites. The identification of post-translational histone modifications and chromatin-modifying enzymes is beginning to reveal both common and novel functions for chromatin in these parasites. In this Review, we compare the role of epigenetics in African trypanosomes and humans in several biological processes. We discuss how the study of trypanosome chromatin might help us to better understand the evolution of epigenetic processes.
Collapse
|
47
|
Abstract
The long polycistronic transcription units of trypanosomes do not appear to be demarcated by the usual DNA motifs that punctuate transcription in familiar eukaryotes. In this issue of Genes & Development, Siegel and colleagues (pp. 1063-1076) describe a system for the demarcation of trypanosome transcription units based on the deposition and turnover of histone variants rather than on the binding of transcription factors. Replication-independent incorporation of histone variants and destabilization of nucleosomes is an emerging theme at promoters of more familiar eukaryotes, and it now appears that this system is an evolutionarily conserved mode of transcriptional punctuation.
Collapse
Affiliation(s)
- Paul B Talbert
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
| | | |
Collapse
|
48
|
Siegel TN, Hekstra DR, Kemp LE, Figueiredo LM, Lowell JE, Fenyo D, Wang X, Dewell S, Cross GAM. Four histone variants mark the boundaries of polycistronic transcription units in Trypanosoma brucei. Genes Dev 2009; 23:1063-76. [PMID: 19369410 DOI: 10.1101/gad.1790409] [Citation(s) in RCA: 267] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Unusually for a eukaryote, genes transcribed by RNA polymerase II (pol II) in Trypanosoma brucei are arranged in polycistronic transcription units. With one exception, no pol II promoter motifs have been identified, and how transcription is initiated remains an enigma. T. brucei has four histone variants: H2AZ, H2BV, H3V, and H4V. Using chromatin immunoprecipitation (ChIP) and sequencing (ChIP-seq) to examine the genome-wide distribution of chromatin components, we show that histones H4K10ac, H2AZ, H2BV, and the bromodomain factor BDF3 are enriched up to 300-fold at probable pol II transcription start sites (TSSs). We also show that nucleosomes containing H2AZ and H2BV are less stable than canonical nucleosomes. Our analysis also identifies >60 unexpected TSS candidates and reveals the presence of long guanine runs at probable TSSs. Apparently unique to trypanosomes, additional histone variants H3V and H4V are enriched at probable pol II transcription termination sites. Our findings suggest that histone modifications and histone variants play crucial roles in transcription initiation and termination in trypanosomes and that destabilization of nucleosomes by histone variants is an evolutionarily ancient and general mechanism of transcription initiation, demonstrated in an organism in which general pol II transcription factors have been elusive.
Collapse
Affiliation(s)
- T Nicolai Siegel
- Laboratory of Molecular Parasitology, The Rockefeller University, New York, New York 10065, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Villanova GV, Nardelli SC, Cribb P, Magdaleno A, Silber AM, Motta MCM, Schenkman S, Serra E. Trypanosoma cruzi bromodomain factor 2 (BDF2) binds to acetylated histones and is accumulated after UV irradiation. Int J Parasitol 2008; 39:665-73. [PMID: 19136002 DOI: 10.1016/j.ijpara.2008.11.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/14/2008] [Accepted: 11/18/2008] [Indexed: 11/27/2022]
Abstract
Histone tail post-translational modifications (acetylation, methylation, phosphorylation, ubiquitination and ADP-ribosylation) regulate many cellular processes. Among these modifications, phosphorylation, methylation and acetylation have already been described in trypanosomatid histones. Bromodomains, together with chromodomains and histone-binding SANT domains, were proposed to be responsible for "histone code" reading. The Trypanosoma cruzi genome encodes four coding sequences (CDSs) that contain a bromodomain, named TcBDF1-4. Here we show that one of those, TcBDF2, is expressed in discrete regions inside the nucleus of all the parasite life cycle stages and binds H4 and H2A purified histones from T. cruzi. Immunolocalization experiments using both anti-histone H4 acetylated peptides and anti-TcBDF2 antibodies determined that TcBDF2 co-localizes with histone H4 acetylated at lysines K10 and K14. TcDBF2 and K10 acetylated H4 interaction was confirmed by co-immunoprecipitation. It is also shown that TcBDF2 was accumulated after UV irradiation of T. cruzi epimastigotes. These results suggest that TcBDF2 could be taking part in a chromatin remodelling complex in T. cruzi.
Collapse
Affiliation(s)
- Gabriela Vanina Villanova
- Instituto de Biología Molecular y Celular de Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Suipacha 351, 2000, Rosario, Argentina
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Respuela P, Ferella M, Rada-Iglesias A, Åslund L. Histone acetylation and methylation at sites initiating divergent polycistronic transcription in Trypanosoma cruzi. J Biol Chem 2008; 283:15884-92. [PMID: 18400752 PMCID: PMC3259629 DOI: 10.1074/jbc.m802081200] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Indexed: 01/23/2023] Open
Abstract
Trypanosomes are ancient eukaryotic parasites in which the protein-coding genes, organized in large polycistronic clusters on both strands, are transcribed from as yet unidentified promoters. In an effort to reveal transcriptional initiation sites, we examined the Trypanosoma cruzi genome for histone modification patterns shown to be linked to active genes in various organisms. Here, we show that acetylated and methylated histones were found to be enriched at strand switch regions of divergent gene arrays, not at convergent clusters or intra- and intergenic regions within clusters. The modified region showed a bimodular profile with two peaks centered over the 5'-regions of the gene pair flanking the strand switch region. This pattern, which demarcates polycistronic transcription units originating from bidirectional initiation sites, is likely to be common in kinetoplastid parasites as well as in other organisms with polycistronic transcription. In contrast, no acetylation was found at promoters of the highly expressed rRNA and spliced leader genes or satellite DNA or at tested retrotransposonal elements. These results reveal, for the first time, the presence of specific epigenetic marks in T. cruzi with potential implications for transcriptional regulation; they indicate that both histone modifications and bidirectional transcription are evolutionarily conserved.
Collapse
Affiliation(s)
- Patricia Respuela
- Department of Genetics and Pathology,
Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden and the
Program for Genomics and Bioinformatics,
Department of Cell and Molecular Biology, Karolinska Institute, SE-171 77
Stockholm, Sweden
| | - Marcela Ferella
- Department of Genetics and Pathology,
Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden and the
Program for Genomics and Bioinformatics,
Department of Cell and Molecular Biology, Karolinska Institute, SE-171 77
Stockholm, Sweden
| | - Alvaro Rada-Iglesias
- Department of Genetics and Pathology,
Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden and the
Program for Genomics and Bioinformatics,
Department of Cell and Molecular Biology, Karolinska Institute, SE-171 77
Stockholm, Sweden
| | - Lena Åslund
- Department of Genetics and Pathology,
Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden and the
Program for Genomics and Bioinformatics,
Department of Cell and Molecular Biology, Karolinska Institute, SE-171 77
Stockholm, Sweden
| |
Collapse
|