1
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Morioka S, Sato S, Horikoshi N, Kujirai T, Tomita T, Baba Y, Kakuta T, Ogoshi T, Puppulin L, Sumino A, Umeda K, Kodera N, Kurumizaka H, Shibata M. High-Speed Atomic Force Microscopy Reveals Spontaneous Nucleosome Sliding of H2A.Z at the Subsecond Time Scale. NANO LETTERS 2023; 23:1696-1704. [PMID: 36779562 DOI: 10.1021/acs.nanolett.2c04346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Nucleosome dynamics, such as nucleosome sliding and DNA unwrapping, are important for gene regulation in eukaryotic chromatin. H2A.Z, a variant of histone H2A that is highly evolutionarily conserved, participates in gene regulation by forming unstable multipositioned nucleosomes in vivo and in vitro. However, the subsecond dynamics of this unstable nucleosome have not been directly visualized under physiological conditions. Here, we used high-speed atomic force microscopy (HS-AFM) to directly visualize the subsecond dynamics of human H2A.Z.1-nucleosomes. HS-AFM videos show nucleosome sliding along 4 nm of DNA within 0.3 s in any direction. This sliding was also visualized in an H2A.Z.1 mutant, in which the C-terminal half was replaced by the corresponding canonical H2A amino acids, indicating that the interaction between the N-terminal region of H2A.Z.1 and the DNA is responsible for nucleosome sliding. These results may reveal the relationship between nucleosome dynamics and gene regulation by histone H2A.Z.
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Affiliation(s)
- Shin Morioka
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Shoko Sato
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Naoki Horikoshi
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Tomoya Kujirai
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Takuya Tomita
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Yudai Baba
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Takahiro Kakuta
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Tomoki Ogoshi
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Leonardo Puppulin
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Ayumi Sumino
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
- Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - Kenichi Umeda
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Noriyuki Kodera
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Mikihiro Shibata
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
- Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
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2
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Simmons JR, An R, Amankwaa B, Zayac S, Kemp J, Labrador M. Phosphorylated histone variant γH2Av is associated with chromatin insulators in Drosophila. PLoS Genet 2022; 18:e1010396. [PMID: 36197938 PMCID: PMC9576066 DOI: 10.1371/journal.pgen.1010396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 10/17/2022] [Accepted: 08/24/2022] [Indexed: 11/27/2022] Open
Abstract
Chromatin insulators are responsible for orchestrating long-range interactions between enhancers and promoters throughout the genome and align with the boundaries of Topologically Associating Domains (TADs). Here, we demonstrate an association between gypsy insulator proteins and the phosphorylated histone variant H2Av (γH2Av), normally a marker of DNA double strand breaks. Gypsy insulator components colocalize with γH2Av throughout the genome, in polytene chromosomes and in diploid cells in which Chromatin IP data shows it is enriched at TAD boundaries. Mutation of insulator components su(Hw) and Cp190 results in a significant reduction in γH2Av levels in chromatin and phosphatase inhibition strengthens the association between insulator components and γH2Av and rescues γH2Av localization in insulator mutants. We also show that γH2Av, but not H2Av, is a component of insulator bodies, which are protein condensates that form during osmotic stress. Phosphatase activity is required for insulator body dissolution after stress recovery. Together, our results implicate the H2A variant with a novel mechanism of insulator function and boundary formation.
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Affiliation(s)
- James R. Simmons
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Ran An
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Bright Amankwaa
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Shannon Zayac
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Justin Kemp
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Mariano Labrador
- Department of Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
- * E-mail:
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3
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Osakabe A, Molaro A. Histone renegades: Unusual H2A histone variants in plants and animals. Semin Cell Dev Biol 2022; 135:35-42. [PMID: 35570098 DOI: 10.1016/j.semcdb.2022.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/19/2022] [Accepted: 05/04/2022] [Indexed: 12/27/2022]
Abstract
H2A variants are histones that carry out specialized nucleosome function during the eukaryote genome packaging. Most genes encoding H2A histone variants arose in the distant past, and have highly conserved domains and structures. Yet, novel H2A variants have continued to arise throughout the radiation of eukaryotes and disturbed the apparent tranquility of nucleosomes. These species-specific H2A variants contributed to the functional diversification of nucleosomes through changes in both their structure and expression patterns. In this short review, we discuss the evolutionary trajectories of these histone renegades in plants and animal genomes.
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Affiliation(s)
- Akihisa Osakabe
- Laboratory of Genetics, Department of Biological Sciences, The University of Tokyo, Tokyo, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan.
| | - Antoine Molaro
- Genetics, Reproduction & Development Institute (iGReD), CNRS UMR 6293, INSERM U1103, Université Clermont Auvergne, Clermont-Ferrand, France.
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Matsuo Y. The Adenine/Thymine Deleterious Selection Model for GC Content Evolution at the Third Codon Position of the Histone Genes in Drosophila. Genes (Basel) 2021; 12:721. [PMID: 34065869 PMCID: PMC8150595 DOI: 10.3390/genes12050721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/07/2021] [Accepted: 05/07/2021] [Indexed: 12/02/2022] Open
Abstract
The evolution of the GC (guanine cytosine) content at the third codon position of the histone genes (H1, H2A, H2B, H3, H4, H2AvD, H3.3A, H3.3B, and H4r) in 12 or more Drosophila species is reviewed. For explaining the evolution of the GC content at the third codon position of the genes, a model assuming selection with a deleterious effect for adenine/thymine and a size effect is presented. The applicability of the model to whole-genome genes is also discussed.
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Affiliation(s)
- Yoshinori Matsuo
- Division of Science and Technology, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan
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5
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The histone replacement gene His4r is involved in heat stress induced chromatin rearrangement. Sci Rep 2021; 11:4878. [PMID: 33649489 PMCID: PMC7921661 DOI: 10.1038/s41598-021-84413-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 02/16/2021] [Indexed: 01/31/2023] Open
Abstract
His4r is the only known variant of histone H4 in Drosophila. It is encoded by the His4r single-copy gene that is located outside of the histone gene cluster and expressed in a different pattern than H4, although the encoded polypeptides are identical. We generated a null mutant (His4rΔ42) which is homozygous viable and fertile without any apparent morphological defects. Heterozygous His4rΔ42 is a mild suppressor of position-effect variegation, suggesting that His4r has a role in the formation or maintenance of condensed chromatin. Under standard conditions loss of His4r has a modest effect on gene expression. Upon heat-stress the induction of the Heat shock protein (HSP) genes Hsp27 and Hsp68 is stronger in His4rΔ42 mutants with concordantly increased survival rate. Analysis of chromatin accessibility after heat shock at a Hsp27 regulatory region showed less condensed chromatin in the absence of His4r while there was no difference at the gene body. Interestingly, preconditioning before heat shock led to increased chromatin accessibility, HSP gene transcription and survival rate in control flies while it did not cause notable changes in His4rΔ42. Thus, our results suggest that His4r might play a role in fine tuning chromatin structure at inducible gene promoters upon environmental stress conditions.
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Vidaurre V, Chen X. Epigenetic regulation of drosophila germline stem cell maintenance and differentiation. Dev Biol 2021; 473:105-118. [PMID: 33610541 DOI: 10.1016/j.ydbio.2021.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/26/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022]
Abstract
Gametogenesis is one of the most extreme cellular differentiation processes that takes place in Drosophila male and female germlines. This process begins at the germline stem cell, which undergoes asymmetric cell division (ACD) to produce a self-renewed daughter that preserves its stemness and a differentiating daughter cell that undergoes epigenetic and genomic changes to eventually produce haploid gametes. Research in molecular genetics and cellular biology are beginning to take advantage of the continually advancing genomic tools to understand: (1) how germ cells are able to maintain their identity throughout the adult reproductive lifetime, and (2) undergo differentiation in a balanced manner. In this review, we focus on the epigenetic mechanisms that address these two questions through their regulation of germline-soma communication to ensure germline stem cell identity and activity.
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Affiliation(s)
- Velinda Vidaurre
- Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD, 21218, USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Baltimore, MD, 21218, USA.
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7
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Histone variant H2A.B-H2B dimers are spontaneously exchanged with canonical H2A-H2B in the nucleosome. Commun Biol 2021; 4:191. [PMID: 33580188 PMCID: PMC7881002 DOI: 10.1038/s42003-021-01707-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 01/11/2021] [Indexed: 01/07/2023] Open
Abstract
H2A.B is an evolutionarily distant histone H2A variant that accumulates on DNA repair sites, DNA replication sites, and actively transcribing regions in genomes. In cells, H2A.B exchanges rapidly in chromatin, but the mechanism has remained enigmatic. In the present study, we found that the H2A.B-H2B dimer incorporated within the nucleosome exchanges with the canonical H2A-H2B dimer without assistance from additional factors, such as histone chaperones and nucleosome remodelers. High-speed atomic force microscopy revealed that the H2A.B nucleosome, but not the canonical H2A nucleosome, transiently forms an intermediate "open conformation", in which two H2A.B-H2B dimers may be detached from the H3-H4 tetramer and bind to the DNA regions near the entry/exit sites. Mutational analyses revealed that the H2A.B C-terminal region is responsible for the adoption of the open conformation and the H2A.B-H2B exchange in the nucleosome. These findings provide mechanistic insights into the histone exchange of the H2A.B nucleosome.
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Genome-wide identification and transcriptional modulation of histone variants and modification related genes in the low pH-exposed marine rotifer Brachionus koreanus. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 36:100748. [PMID: 33032078 DOI: 10.1016/j.cbd.2020.100748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/05/2020] [Accepted: 09/18/2020] [Indexed: 11/22/2022]
Abstract
Histone modification is considered to be a major epigenetic control mechanism. These modifications (e.g. acetylation, phosphorylation, and methylation) may affect the interaction of histones with DNA and/or regulate DNA-based processes (e.g., recombination, repair, replication, and transcription) and chromatin remodeling complexes. Despite their significance in metazoan life and evolution, few studies have been conducted to identify genes undergoing epigenetic control modification in aquatic invertebrates. In this study, we identified whole core histones (70 total genes) and post-translational modification (PTM) histone genes (63 total genes) in the marine rotifer Brachionus koreanus through whole-genome analysis, and annotated them according to the human nomenclature. Notably, upon comparative analysis of cis-regulatory motif sequences, we found that B. koreanus core histone protein structures were similar to those of mammals. Furthermore, to examine the effect of parental low pH stress on the offspring's epigenetic regulation, we investigated the expression of PTM genes in two generations of B. koreanus exposed to low pH conditions. Given that the B. koreanus genome does not possess DNA methyltransferase 1 and 3 genes, we concluded that histone genes could be involved as an important epigenetic mechanism in B. koreanus. Therefore, the histone-associated genes identified in this study could be useful for ecotoxicological studies and facilitate the application of chromatin immunoprecipitation sequencing using high-throughput DNA sequencing based on the genome-wide identification of transcription factor binding sites in rotifers.
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Sato S, Tanaka N, Arimura Y, Kujirai T, Kurumizaka H. The N-terminal and C-terminal halves of histone H2A.Z independently function in nucleosome positioning and stability. Genes Cells 2020; 25:538-546. [PMID: 32500630 PMCID: PMC7496805 DOI: 10.1111/gtc.12791] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/28/2020] [Accepted: 05/08/2020] [Indexed: 01/21/2023]
Abstract
Nucleosome positioning and stability affect gene regulation in eukaryotic chromatin. Histone H2A.Z is an evolutionally conserved histone variant that forms mobile and unstable nucleosomes in vivo and in vitro. In the present study, we reconstituted nucleosomes containing human H2A.Z.1 mutants, in which the N‐terminal or C‐terminal half of H2A.Z.1 was replaced by the corresponding canonical H2A region. We found that the N‐terminal portion of H2A.Z.1 is involved in flexible nucleosome positioning, whereas the C‐terminal portion leads to weak H2A.Z.1‐H2B association in the nucleosome. These results indicate that the N‐terminal and C‐terminal portions are independently responsible for the H2A.Z.1 nucleosome characteristics.
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Affiliation(s)
- Shoko Sato
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Naoki Tanaka
- Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Yasuhiro Arimura
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.,Laboratory of Chromosome and Cell Biology, The Rockefeller University, New York, NY, USA
| | - Tomoya Kujirai
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.,Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
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10
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Cheema MS, Good KV, Kim B, Soufari H, O’Sullivan C, Freeman ME, Stefanelli G, Casas CR, Zengeler KE, Kennedy AJ, Eirin Lopez JM, Howard PL, Zovkic IB, Shabanowitz J, Dryhurst DD, Hunt DF, Mackereth CD, Ausió J. Deciphering the Enigma of the Histone H2A.Z-1/H2A.Z-2 Isoforms: Novel Insights and Remaining Questions. Cells 2020; 9:cells9051167. [PMID: 32397240 PMCID: PMC7290884 DOI: 10.3390/cells9051167] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/20/2022] Open
Abstract
The replication independent (RI) histone H2A.Z is one of the more extensively studied variant members of the core histone H2A family, which consists of many replication dependent (RD) members. The protein has been shown to be indispensable for survival, and involved in multiple roles from DNA damage to chromosome segregation, replication, and transcription. However, its functional involvement in gene expression is controversial. Moreover, the variant in several groups of metazoan organisms consists of two main isoforms (H2A.Z-1 and H2A.Z-2) that differ in a few (3–6) amino acids. They comprise the main topic of this review, starting from the events that led to their identification, what is currently known about them, followed by further experimental, structural, and functional insight into their roles. Despite their structural differences, a direct correlation to their functional variability remains enigmatic. As all of this is being elucidated, it appears that a strong functional involvement of isoform variability may be connected to development.
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Affiliation(s)
- Manjinder S. Cheema
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Katrina V. Good
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Bohyun Kim
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Heddy Soufari
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, 2 rue Robert Escarpit, F-33607 Pessac, France; (H.S.); (C.D.M.)
- Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Connor O’Sullivan
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Melissa E. Freeman
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Gilda Stefanelli
- Department of Neurosciences & Mental Health, the Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (G.S.); (I.B.Z.)
| | - Ciro Rivera Casas
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International UniversityNorth Miami, FL 33181, USA; (C.R.C.); (J.M.E.L.)
| | - Kristine E. Zengeler
- Department of Chemistry and Biochemistry, Bates College, 2 Andrews Road, Lewiston, ME 04240, USA; (K.E.Z.); (A.J.K.)
| | - Andrew J. Kennedy
- Department of Chemistry and Biochemistry, Bates College, 2 Andrews Road, Lewiston, ME 04240, USA; (K.E.Z.); (A.J.K.)
| | - Jose Maria Eirin Lopez
- Environmental Epigenetics Group, Department of Biological Sciences, Florida International UniversityNorth Miami, FL 33181, USA; (C.R.C.); (J.M.E.L.)
| | - Perry L. Howard
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Iva B. Zovkic
- Department of Neurosciences & Mental Health, the Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; (G.S.); (I.B.Z.)
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; (J.S.); (D.F.H.)
| | - Deanna D. Dryhurst
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
| | - Donald F. Hunt
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; (J.S.); (D.F.H.)
- Department of Pathology, University of Virginia, Charlottesville, VA 22903, USA
| | - Cameron D. Mackereth
- Institut Européen de Chimie et Biologie, Univ. Bordeaux, 2 rue Robert Escarpit, F-33607 Pessac, France; (H.S.); (C.D.M.)
- Inserm U1212, CNRS UMR 5320, ARNA Laboratory, Univ. Bordeaux, 146 rue Léo Saignat, F-33076 Bordeaux, France
| | - Juan Ausió
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada; (M.S.C.); (K.V.G.); (B.K.); (C.O.); (M.E.F.); (P.L.H.); (D.D.D.)
- Correspondence: ; Tel.: +1-250-721-8863; Fax: +1-250-721-8855
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11
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Giaimo BD, Ferrante F, Herchenröther A, Hake SB, Borggrefe T. The histone variant H2A.Z in gene regulation. Epigenetics Chromatin 2019; 12:37. [PMID: 31200754 PMCID: PMC6570943 DOI: 10.1186/s13072-019-0274-9] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/23/2019] [Indexed: 01/04/2023] Open
Abstract
The histone variant H2A.Z is involved in several processes such as transcriptional control, DNA repair, regulation of centromeric heterochromatin and, not surprisingly, is implicated in diseases such as cancer. Here, we review the recent developments on H2A.Z focusing on its role in transcriptional activation and repression. H2A.Z, as a replication-independent histone, has been studied in several model organisms and inducible mammalian model systems. Its loading machinery and several modifying enzymes have been recently identified, and some of the long-standing discrepancies in transcriptional activation and/or repression are about to be resolved. The buffering functions of H2A.Z, as supported by genome-wide localization and analyzed in several dynamic systems, are an excellent example of transcriptional control. Posttranslational modifications such as acetylation and ubiquitination of H2A.Z, as well as its specific binding partners, are in our view central players in the control of gene expression. Understanding the key-mechanisms in either turnover or stabilization of H2A.Z-containing nucleosomes as well as defining the H2A.Z interactome will pave the way for therapeutic applications in the future.
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Affiliation(s)
| | - Francesca Ferrante
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Andreas Herchenröther
- Institute for Genetics, University of Giessen, Heinrich-Buff-Ring 58-62, 35392, Giessen, Germany
| | - Sandra B Hake
- Institute for Genetics, University of Giessen, Heinrich-Buff-Ring 58-62, 35392, Giessen, Germany
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392, Giessen, Germany.
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12
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Khuong MT, Fei J, Cruz-Becerra G, Kadonaga JT. A simple and versatile system for the ATP-dependent assembly of chromatin. J Biol Chem 2017; 292:19478-19490. [PMID: 28982979 DOI: 10.1074/jbc.m117.815365] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/26/2017] [Indexed: 12/17/2022] Open
Abstract
Chromatin is the natural form of DNA in the eukaryotic nucleus and is the substrate for diverse biological phenomena. The functional analysis of these processes ideally would be carried out with nucleosomal templates that are assembled with customized core histones, DNA sequences, and chromosomal proteins. Here we report a simple, reliable, and versatile method for the ATP-dependent assembly of evenly spaced nucleosome arrays. This minimal chromatin assembly system comprises the Drosophila nucleoplasmin-like protein (dNLP) histone chaperone, the imitation switch (ISWI) ATP-driven motor protein, core histones, template DNA, and ATP. The dNLP and ISWI components were synthesized in bacteria, and each protein could be purified in a single step by affinity chromatography. We show that the dNLP-ISWI system can be used with different DNA sequences, linear or circular DNA, bulk genomic DNA, recombinant or native Drosophila core histones, native human histones, the linker histone H1, the non-histone chromosomal protein HMGN2, and the core histone variants H3.3 and H2A.V. The dNLP-ISWI system should be accessible to a wide range of researchers and enable the assembly of customized chromatin with specifically desired DNA sequences, core histones, and other chromosomal proteins.
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Affiliation(s)
- Mai T Khuong
- From the Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093
| | - Jia Fei
- From the Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093
| | - Grisel Cruz-Becerra
- From the Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093
| | - James T Kadonaga
- From the Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093
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13
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Abstract
Eukaryotes package DNA into nucleosomes that contain a core of histone proteins. During DNA replication, nucleosomes are disrupted and re-assembled with newly synthesized histones and DNA. Despite much progress, it is still unclear why higher eukaryotes contain multiple core histone genes, how chromatin assembly is controlled, and how these processes are coordinated with cell cycle progression. We used a histone null mutation of Drosophila melanogaster to show that histone supply levels, provided by a defined number of transgenic histone genes, regulate the length of S phase during the cell cycle. Lack of de novo histone supply not only extends S phase, but also causes a cell cycle arrest during G2 phase, and thus prevents cells from entering mitosis. Our results suggest a novel cell cycle surveillance mechanism that monitors nucleosome assembly without involving the DNA repair pathways and exerts its effect via suppression of CDC25 phosphatase String expression. DOI:http://dx.doi.org/10.7554/eLife.02443.001 As a cell prepares to divide, it goes through four distinct stages. First, it grows in size (G1 phase); next it copies its entire DNA content (S phase); then it grows some more (G2 phase); and, last, it splits into two new cells (M phase). During S phase, groups of histone proteins that normally stick together to tightly package the DNA are pulled apart in order to make the DNA accessible for copying. After the DNA has been duplicated, both copies of the DNA strand need to be repackaged. Therefore, after copying the DNA the cell rapidly reassembles the DNA–histone complexes (called nucleosomes), using a combination of old and newly synthesized histones to do so. A cell can adjust how quickly it copies DNA according to the availability of these histone proteins, which is important because copying DNA without the resources to package it could expose the DNA to damage. Here, Günesdogan et al. investigate how a cell controls these processes using a mutant of the fruit fly Drosophila melanogaster that completely lacks the genes required to make histones. Cells that lack histones copy their DNA very slowly but adding copies of histone genes back into these flies speeds up the rate at which DNA is copied. Günesdogan et al. ask whether the slower speed of DNA replication in cells without new histones is connected to preventing DNA damage. However, these cells can still copy all their DNA, despite being unable to package it, so the higher risk of making mistakes is not enough to stop S phase. In fact, indications suggest that DNA damage detection methods continue to work as normal in cells without histones: these cells can get all the way to the end of G2 phase without any problems. To go one step further and start splitting in two, a cell needs to switch on another gene, called string in the fruit fly and CDC25 in vertebrates, which makes an enzyme required for the cell division process. Normal cells switch on string during G2 phase, but cells that lack histones do not—and therefore do not enter M phase. Günesdogan et al. show that turning on string by a genetic trick is sufficient to overcome this cell cycle arrest and drive the cells into M phase. String could therefore form part of a surveillance mechanism that blocks cell division if DNA–histone complexes are not assembled correctly. DOI:http://dx.doi.org/10.7554/eLife.02443.002
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Affiliation(s)
- Ufuk Günesdogan
- Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, United Kingdom
| | - Herbert Jäckle
- Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Alf Herzig
- Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany Abteilung Zelluläre Mikrobiologie, Max-Planck-Institut für Infektionsbiologie, Berlin, Germany
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14
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Fang X, Ide N, Higashi SI, Kamei Y, Toyooka T, Ibuki Y, Kawai K, Kasai H, Okamoto K, Arimoto-Kobayashi S, Negishi T. Somatic cell mutations caused by 365 nm LED-UVA due to DNA double-strand breaks through oxidative damage. Photochem Photobiol Sci 2014; 13:1338-46. [DOI: 10.1039/c4pp00148f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15
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Billon P, Côté J. Precise deposition of histone H2A.Z in chromatin for genome expression and maintenance. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1819:290-302. [PMID: 24459731 DOI: 10.1016/j.bbagrm.2011.10.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Histone variant H2A.Z is essential in higher eukaryotes and has different functions in the cell. Several studies indicate that H2A.Z is found at specific loci in the genome such as regulatory-gene regions, where it poises genes for transcription. Itsdeposition creates chromatin regions with particular structural characteristics which could favor rapid transcription activation. This review focuses on the highly regulated mechanism of H2A.Z deposition in chromatin which is essential for genome integrity. Chaperones escort H2A.Z to large ATP-dependent chromatin remodeling enzymes which are responsible for its deposition/eviction. Over the last ten years, biochemical, genetic and genomic studies helped us understand the precise role of these complexes in this process. It hasbeen suggested that a cooperation occurs between histone acetyltransferase and chromatin remodeling activities to incorporate H2A.Z in chromatin. Its regulated deposition near centromeres and telomeres also shows its implication in chromosomal structure integrity and parallels a role in DNA damage response. Thedynamics of H2A.Z deposition/eviction at specific loci was shown to be critical for genome expression andmaintenance, thus cell fate. Altogether, recent findings reassert the importance of the regulated depositionof this histone variant. This article is part of a Special Issue entitled: Histone chaperones and Chromatin assembly.
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16
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Morillo Prado JR, Srinivasan S, Fuller MT. The histone variant His2Av is required for adult stem cell maintenance in the Drosophila testis. PLoS Genet 2013; 9:e1003903. [PMID: 24244183 PMCID: PMC3820763 DOI: 10.1371/journal.pgen.1003903] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 09/08/2013] [Indexed: 12/19/2022] Open
Abstract
Many tissues are sustained by adult stem cells, which replace lost cells by differentiation and maintain their own population through self-renewal. The mechanisms through which adult stem cells maintain their identity are thus important for tissue homeostasis and repair throughout life. Here, we show that a histone variant, His2Av, is required cell autonomously for maintenance of germline and cyst stem cells in the Drosophila testis. The ATP-dependent chromatin-remodeling factor Domino is also required in this tissue for adult stem cell maintenance possibly by regulating the incorporation of His2Av into chromatin. Interestingly, although expression of His2Av was ubiquitous, its function was dispensable for germline and cyst cell differentiation, suggesting a specific role for this non-canonical histone in maintaining the stem cell state in these lineages.
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Affiliation(s)
- Jose Rafael Morillo Prado
- Department of Developmental Biology, Stanford University, School of Medicine Stanford, California, United States of America
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17
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The variant histone H2A.V of Drosophila--three roles, two guises. Chromosoma 2013; 122:245-58. [PMID: 23553272 DOI: 10.1007/s00412-013-0409-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/19/2013] [Accepted: 03/21/2013] [Indexed: 12/15/2022]
Abstract
Histone variants play important roles in eukaryotic genome organization, the control of gene expression, cell division and DNA repair. Unlike other organisms that employ several H2A variants for different functions, the parsimonious fruit fly Drosophila melanogaster gets along with just a single H2A variant, H2A.V. Remarkably, H2A.V unites within one molecule features and functions of two different mammalian H2A variants, H2A.Z and H2A.X. Accordingly, H2A.V is involved in diverse functions, as an element of a class of active promoter structure, as a foundation for heterochromatin assembly and as a DNA damage sensor. Here, we comprehensively review the current knowledge of this fascinating histone variant.
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Shoaib M, Kulyyassov A, Robin C, Winczura K, Tarlykov P, Despas E, Kannouche P, Ramanculov E, Lipinski M, Ogryzko V. PUB-NChIP--"in vivo biotinylation" approach to study chromatin in proximity to a protein of interest. Genome Res 2012; 23:331-40. [PMID: 23038767 PMCID: PMC3561874 DOI: 10.1101/gr.134874.111] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We have developed an approach termed PUB-NChIP (proximity utilizing biotinylation with native ChIP) to purify and study the protein composition of chromatin in proximity to a nuclear protein of interest. It is based on coexpression of (1) a protein of interest, fused with the bacterial biotin ligase BirA, together with (2) a histone fused to a biotin acceptor peptide (BAP), which is specifically biotinylated by BirA-fusion in the proximity of the protein of interest. Using the RAD18 protein as a model, we demonstrate that the RAD18-proximal chromatin is enriched in some H4 acetylated species. Moreover, the RAD18-proximal chromatin containing a replacement histone H2AZ has a different pattern of H4 acetylation. Finally, biotin pulse-chase experiments show that the H4 acetylation pattern starts to resemble the acetylation pattern of total H4 after the proximity of chromatin to RAD18 has been lost.
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Affiliation(s)
- Muhammad Shoaib
- UMR8126, Université Paris-Sud 11, CNRS, Institut de Cancérologie Gustave Roussy, 94805 Villejuif, France
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19
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Svotelis A, Gévry N, Gaudreau L. Regulation of gene expression and cellular proliferation by histone H2A.Z. Biochem Cell Biol 2009; 87:179-88. [PMID: 19234533 DOI: 10.1139/o08-138] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The mammalian genome is organized into a structure of DNA and proteins known as chromatin. In general, chromatin presents a barrier to gene expression that is regulated by several pathways, namely by the incorporation of histone variants into the nucleosome. In yeast, H2A.Z is an H2A histone variant that is incorporated into nucleosomes as an H2A.Z/H2B dimer by the Swr1 complex and by the SRCAP and p400/Tip60 complexes in mammalian cells. H2A.Z has been associated with the poising of genes for transcriptional activation in the yeast model system, and is essential for development in higher eukaryotes. Recent studies in our laboratory have demonstrated a p400-dependent deposition of H2A.Z at the promoter of p21WAF1/CIP1, a consequence that prevents the activation of the gene by p53, thereby inhibiting p53-dependent replicative senescence, a form of cell-cycle arrest crucial in the prevention of carcinogenic transformation of cells. Moreover, H2A.Z is overexpressed in several different types of cancers, and its overexpression has been associated functionally with the proliferation state of cells. Therefore, we suggest that H2A.Z is an important regulator of gene expression, and its deregulation may lead to the increased proliferation of mammalian cells.
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Affiliation(s)
- Amy Svotelis
- Departement de biologie, Faculte des Sciences, Universite de Sherbrooke, Sherbrooke, QCJ1K2R1, Canada
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20
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Ramaswamy A, Ioshikhes I. Global dynamics of newly constructed oligonucleosomes of conventional and variant H2A.Z histone. BMC STRUCTURAL BIOLOGY 2007; 7:76. [PMID: 17996059 PMCID: PMC2216022 DOI: 10.1186/1472-6807-7-76] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 11/08/2007] [Indexed: 11/16/2022]
Abstract
Background Complexes of nucleosomes, which often occur in the gene promoter areas, are one of the fundamental levels of chromatin organization and thus are important for transcription regulation. Investigating the dynamic structure of a single nucleosome as well as nucleosome complexes is important for understanding transcription within chromatin. In a previous work, we highlighted the influence of histone variants on the functional dynamics of a single nucleosome using normal mode analysis developed by Bahar et al. The present work further analyzes the dynamics of nucleosome complexes (nucleosome oligomers or oligonucleosomes) such as dimer, trimer and tetramer (beads on a string model) with conventional core histones as well as with the H2A.Z histone variant using normal mode analysis. Results The global dynamics of oligonucleosomes reveal larger amplitude of motion within the nucleosomes that contain the H2A.Z variant with in-planar and out-of-planar fluctuations as the common mode of relaxation. The docking region of H2A.Z and the L1:L1 interactions between H2A.Z monomers of nucleosome (that are responsible for the highly stable nucleosome containing variant H2A.Z-histone) are highly dynamic throughout the first two dynamic modes. Conclusion Dissection of the dynamics of oligonucleosomes discloses in-plane as well as out-of-plane fluctuations as the common mode of relaxation throughout the global motions. The dynamics of individual nucleosomes and the combination of the relaxation mechanisms expressed by the individual nucleosome are quite interesting and highly dependent on the number of nucleosome fragments present in the complexes. Distortions generated by the non-planar dynamics influence the DNA conformation, and hence the histone-DNA interactions significantly alter the dynamics of the DNA. The variant H2A.Z histone is a major source of weaker intra- and inter-molecular correlations resulting in more disordered motions.
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Affiliation(s)
- Amutha Ramaswamy
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA.
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21
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Song X, Gjoneska E, Ren Q, Taverna SD, Allis CD, Gorovsky MA. Phosphorylation of the SQ H2A.X motif is required for proper meiosis and mitosis in Tetrahymena thermophila. Mol Cell Biol 2007; 27:2648-60. [PMID: 17242195 PMCID: PMC1899910 DOI: 10.1128/mcb.01910-06] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Phosphorylation of the C terminus SQ motif that defines H2A.X variants is required for efficient DNA double-strand break (DSB) repair in diverse organisms but has not been studied in ciliated protozoa. Tetrahymena H2A.X is one of two similarly expressed major H2As, thereby differing both from mammals, where H2A.X is a quantitatively minor component, and from Saccharomyces cerevisiae where it is the only type of major H2A. Tetrahymena H2A.X is phosphorylated in the SQ motif in both the mitotic micronucleus and the amitotic macronucleus in response to DSBs induced by chemical agents and in the micronucleus during prophase of meiosis, which occurs in the absence of a synaptonemal complex. H2A.X is phosphorylated when programmed DNA rearrangements occur in developing macronuclei, as for immunoglobulin gene rearrangements in mammals, but not during the DNA fragmentation that accompanies breakdown of the parental macronucleus during conjugation, correcting the previous interpretation that this process is apoptosis-like. Using strains containing a mutated (S134A) SQ motif, we demonstrate that phosphorylation of this motif is important for Tetrahymena cells to recover from exogenous DNA damage and is required for normal micronuclear meiosis and mitosis and, to a lesser extent, for normal amitotic macronuclear division; its absence, while not lethal, leads to the accumulation of DSBs in both micro- and macronuclei. These results demonstrate multiple roles of H2A.X phosphorylation in maintaining genomic integrity in different phases of the Tetrahymena life cycle.
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Affiliation(s)
- Xiaoyuan Song
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
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22
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Abstract
Protozoan parasites are early branching eukaryotes causing significant morbidity and mortality in humans and livestock. Single-celled parasites have evolved complex life cycles, which may involve multiple host organisms, and strategies to evade host immune responses. Consequently, two key aspects of virulence that underlie pathogenesis are parasite differentiation and antigenic variation, both of which require changes in the expressed genome. Complicating these requisite alterations in the parasite transcriptome is chromatin, which serves as a formidable barrier to DNA processes including transcription, repair, replication and recombination. Considerable progress has been made in the study of chromatin dynamics in other eukaryotes, and there is much to be gained in extending these analyses to protozoan parasites. Much of the work completed to date has focused on histone acetylation and methylation in the apicomplexans and trypanosomatids. As we describe in this review, such studies provide a unique vantage point of the evolutionary picture of eukaryotic cell development, and reveal unique phenomena that could be exploited pharmacologically to treat protozoal diseases.
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Affiliation(s)
- William J Sullivan
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA.
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23
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Marzluff WF, Sakallah S, Kelkar H. The sea urchin histone gene complement. Dev Biol 2006; 300:308-20. [PMID: 17078943 DOI: 10.1016/j.ydbio.2006.08.067] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 08/17/2006] [Accepted: 08/28/2006] [Indexed: 11/22/2022]
Abstract
The only eukaryotic mRNAs that are not polyadenylated are the replication-dependent histone mRNAs in metazoans. The sea urchin genome contains two sets of histone genes that encode non-polyadenylated mRNAs. One of these sets is a tandemly repeated gene cluster with a 5.6-kb repeat unit containing one copy of each of the five alpha-histone genes and is present as a single large cluster which spans over 1 Mb. There is a second set of genes, consisting of 39 genes, containing two histone H1 genes, 34 genes encoding core histone proteins (H2a, H2b, H3 and H4) and three genes expressed only in the testis. Unlike vertebrates where these genes are clustered, the sea urchin late histone genes, expressed in embryos, larvae and adults, are dispersed throughout the genome. There are also genes encoding polyadenylated histone mRNAs, which encode histone variants, including all variants found in other metazoans, as well as a unique set of five cleavage stage histone proteins expressed in oocytes. The cleavage stage histone H1 is the orthologue of an oocyte-specific histone H1 protein found in vertebrates.
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Affiliation(s)
- William F Marzluff
- Program in Molecular Biology and Biotechnology, University of North Carolina, Chapel Hill, NC 27599, USA.
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24
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Sivasubbu S, Balciunas D, Davidson AE, Pickart MA, Hermanson SB, Wangensteen KJ, Wolbrink DC, Ekker SC. Gene-breaking transposon mutagenesis reveals an essential role for histone H2afza in zebrafish larval development. Mech Dev 2006; 123:513-29. [PMID: 16859902 DOI: 10.1016/j.mod.2006.06.002] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Revised: 06/02/2006] [Accepted: 06/02/2006] [Indexed: 12/11/2022]
Abstract
We report a novel gene tagging, identification and mutagenicity ('gene-breaking') method for the zebrafish, Danio rerio. This modular approach consists of two distinct and separable molecular cassettes. The first is a gene-finding cassette. In this study, we employed a 3' gene-tagging approach that selectively 'traps' transcripts regardless of expression status, and we show that this cassette identifies both known and novel endogenous transcripts in transgenic zebrafish. The second is a transcriptional termination mutagenicity cassette assembled from a combination of a splice acceptor and polyadenylation signal to disrupt tagged transcripts upon integration into intronic sequence. We identified both novel and conserved loci as linked phenotypic mutations using this gene-breaking strategy, generating molecularly null mutations in both larval lethal and adult viable loci. We show that the Histone 2a family member z (H2afza) variant is essential for larval development through the generation of a lethal locus with a truncation of conserved carboxy-terminal residues in the protein. In principle this gene-breaking strategy is scalable for functional genomics screens and can be used in Sleeping Beauty transposon and other gene delivery systems in the zebrafish.
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Affiliation(s)
- Sridhar Sivasubbu
- University of Minnesota, Department of Genetics, Cell Biology and Development, Arnold and Mabel Beckman Center for Transposon Research, 321 Church St SE, 6-160 Jackson Hall, Minneapolis, MN 55455, USA
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25
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Millar CB, Xu F, Zhang K, Grunstein M. Acetylation of H2AZ Lys 14 is associated with genome-wide gene activity in yeast. Genes Dev 2006; 20:711-22. [PMID: 16543223 PMCID: PMC1413291 DOI: 10.1101/gad.1395506] [Citation(s) in RCA: 224] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Histone variants and their post-translational modifications help regulate chromosomal functions. Htz1 is an evolutionarily conserved H2A variant found at several promoters in the yeast Saccharomyces cerevisiae. In this study, we undertook a genome-wide analysis of Htz1 and its modifications in yeast. Using mass spectrometric analysis, we determined that Htz1 is acetylated at Lys 3, Lys 8, Lys 10, and Lys 14 within its N-terminal tail, with K14 being the most abundant acetylated site. ChIP and microarray analysis were then used to compare the location of Htz1-K14 acetylation to that of Htz1 genome-wide. The data presented here demonstrate that while Htz1 is associated preferentially with the promoters of repressed genes, K14 acetylation is enriched at the promoters of active genes, and requires two known histone acetyltransferases, Gcn5 and Esa1. In support of our genome-wide analysis, we found that the acetylatable lysines of Htz1 are required for its full deposition during nucleosome reassembly upon repression of PHO5. Since the majority of Htz1 acetylation is seen at active promoters, where nucleosomes are known to be disassembled, our data argue for a dynamic process in which reassembly of Htz1 is regulated by its acetylation at promoters during transcription.
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Affiliation(s)
- Catherine B Millar
- Department of Biological Chemistry, Geffen School of Medicine and the Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
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26
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Swaminathan J, Baxter EM, Corces VG. The role of histone H2Av variant replacement and histone H4 acetylation in the establishment of Drosophila heterochromatin. Genes Dev 2005; 19:65-76. [PMID: 15630020 PMCID: PMC540226 DOI: 10.1101/gad.1259105] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Activation and repression of transcription in eukaryotes involve changes in the chromatin fiber that can be accomplished by covalent modification of the histone tails or the replacement of the canonical histones with other variants. Here we show that the histone H2A variant of Drosophila melanogaster, H2Av, localizes to the centromeric heterochromatin, and it is recruited to an ectopic heterochromatin site formed by a transgene array. His2Av behaves genetically as a PcG gene and mutations in His2Av suppress position effect variegation (PEV), suggesting that this histone variant is required for euchromatic silencing and heterochromatin formation. His2Av mutants show reduced acetylation of histone H4 at Lys 12, decreased methylation of histone H3 at Lys 9, and a reduction in HP1 recruitment to the centromeric region. H2Av accumulation or histone H4 Lys 12 acetylation is not affected by mutations in Su(var)3-9 or Su(var)2-5. The results suggest an ordered cascade of events leading to the establishment of heterochromatin and requiring the recruitment of the histone H2Av variant followed by H4 Lys 12 acetylation as necessary steps before H3 Lys 9 methylation and HP1 recruitment can take place.
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27
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Abstract
Histones are a major component of chromatin, the protein-DNA complex fundamental to genome packaging, function, and regulation. A fraction of histones are nonallelic variants that have specific expression, localization, and species-distribution patterns. Here we discuss recent progress in understanding how histone variants lead to changes in chromatin structure and dynamics to carry out specific functions. In addition, we review histone variant assembly into chromatin, the structure of the variant chromatin, and post-translational modifications that occur on the variants.
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28
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Chioda M, Spada F, Eskeland R, Thompson EM. Histone mRNAs do not accumulate during S phase of either mitotic or endoreduplicative cycles in the chordate Oikopleura dioica. Mol Cell Biol 2004; 24:5391-403. [PMID: 15169902 PMCID: PMC419869 DOI: 10.1128/mcb.24.12.5391-5403.2004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Metazoan histones are generally classified as replication-dependent or replacement variants. Replication-dependent histone genes contain cell cycle-responsive promoter elements, their transcripts terminate in an unpolyadenylated conserved stem-loop, and their mRNAs accumulate sharply during S phase. Replacement variant genes lack cell cycle-responsive promoter elements, their polyadenylated transcripts lack the stem-loop, and they are expressed at low levels throughout the cell cycle. During early development of some organisms with rapid cleavage cycles, replication-dependent mRNAs are not fully S phase restricted until complete cell cycle regulation is achieved. The accumulation of polyadenylated transcripts during this period has been considered incompatible with metazoan development. We show here that histone metabolism in the urochordate Oikopleura dioica does not accord with some key tenets of the replication-dependent/replacement variant paradigm. During the premetamorphic mitotic phase of development, expressed variants shared characteristics of replication-dependent histones, including the 3' stem-loop, but, in contrast, were extensively polyadenylated. After metamorphosis, when cells in many tissues enter endocycles, there was a global downregulation of histone transcript levels, with most variant transcripts processed at the stem-loop. Contrary to the 30-fold S-phase upregulation of histone transcripts described in common metazoan model organisms, we observed essentially constant histone transcript levels throughout both mitotic and endoreduplicative cell cycles.
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Affiliation(s)
- Mariacristina Chioda
- Sars International Centre for Marine Molecular Biology, Bergen High Technology Centre, N-5008 Bergen, Norway
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29
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Ridgway P, Rangasamy D, Berven L, Svensson U, Tremethick DJ. Analysis of histone variant H2A.Z localization and expression during early development. Methods Enzymol 2004; 375:239-52. [PMID: 14870671 DOI: 10.1016/s0076-6879(03)75016-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- Patricia Ridgway
- John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory 2601, Australia
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30
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Larochelle M, Gaudreau L. H2A.Z has a function reminiscent of an activator required for preferential binding to intergenic DNA. EMBO J 2003; 22:4512-22. [PMID: 12941702 PMCID: PMC202369 DOI: 10.1093/emboj/cdg427] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
H2A.Z has been shown to regulate transcription in yeast, and that function resides in its C-terminal region as the reciprocal portion of H2A cannot substitute for the latter. We show that fusion of a transcriptional activating region to the C-terminal region of H2A, which is substituted for that of H2A.Z, can allow the chimera to fulfil the special role of H2A.Z in positive gene regulation, as well as complement growth deficiencies of htz1delta cells. We further show that the 'transcription' function of H2A.Z is linked to its ability to preferentially localize to certain intergenic DNA regions. Our results suggest that H2A.Z modulates functional interactions with transcription regulatory components, and thus increases its localization to promoters where it helps poise chromatin for gene activation.
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Affiliation(s)
- Marc Larochelle
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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Rangasamy D, Berven L, Ridgway P, Tremethick DJ. Pericentric heterochromatin becomes enriched with H2A.Z during early mammalian development. EMBO J 2003; 22:1599-607. [PMID: 12660166 PMCID: PMC152904 DOI: 10.1093/emboj/cdg160] [Citation(s) in RCA: 183] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Determining how chromatin is remodelled during early development, when totipotent cells begin to differentiate into specific cell types, is essential to understand how epigenetic states are established. An important mechanism by which chromatin can be remodelled is the replacement of major histones with specific histone variants. During early mammalian development H2A.Z plays an essential, but unknown, function(s). We show here that undifferentiated mouse cells of the inner cell mass lack H2A.Z, but upon differentiation H2A.Z expression is switched on. Strikingly, H2A.Z is first targeted to pericentric hetero chromatin and then to other regions of the nucleus, but is excluded from the inactive X chromosome and the nucleolus. This targeted incorporation of H2A.Z could provide a critical signal to distinguish constitutive from facultative heterochromatin. In support of this model, we demonstrate that H2A.Z can directly interact with the pericentric heterochromatin binding protein INCENP. We propose that H2A.Z functions to establish a specialized pericentric domain by assembling an architecturally distinct chromatin structure and by recruiting specific nuclear proteins.
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Affiliation(s)
- Danny Rangasamy
- The John Curtin School of Medical Research, The Australian National University, PO Box 334, Canberra, Australian Capital Territory 2601, Australia
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32
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Ren Q, Gorovsky MA. The nonessential H2A N-terminal tail can function as an essential charge patch on the H2A.Z variant N-terminal tail. Mol Cell Biol 2003; 23:2778-89. [PMID: 12665578 PMCID: PMC152558 DOI: 10.1128/mcb.23.8.2778-2789.2003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Tetrahymena thermophila cells contain three forms of H2A: major H2A.1 and H2A.2, which make up approximately 80% of total H2A, and a conserved variant, H2A.Z. We showed previously that acetylation of H2A.Z was essential (Q. Ren and M. A. Gorovsky, Mol. Cell 7:1329-1335, 2001). Here we used in vitro mutagenesis of lysine residues, coupled with gene replacement, to identify the sites of acetylation of the N-terminal tail of the major H2A and to analyze its function in vivo. Tetrahymena cells survived with all five acetylatable lysines replaced by arginines plus a mutation that abolished acetylation of the N-terminal serine normally found in the wild-type protein. Thus, neither posttranslational nor cotranslational acetylation of major H2A is essential. Surprisingly, the nonacetylatable N-terminal tail of the major H2A was able to replace the essential function of the acetylation of the H2A.Z N-terminal tail. Tail-swapping experiments between H2A.1 and H2A.Z revealed that the nonessential acetylation of the major H2A N-terminal tail can be made to function as an essential charge patch in place of the H2A.Z N-terminal tail and that while the pattern of acetylation of an H2A N-terminal tail is determined by the tail sequence, the effects of acetylation on viability are determined by properties of the H2A core and not those of the N-terminal tail itself.
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Affiliation(s)
- Qinghu Ren
- Department of Biology, University of Rochester, Rochester, New York 14627, USA
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33
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Madigan JP, Chotkowski HL, Glaser RL. DNA double-strand break-induced phosphorylation of Drosophila histone variant H2Av helps prevent radiation-induced apoptosis. Nucleic Acids Res 2002; 30:3698-705. [PMID: 12202754 PMCID: PMC137418 DOI: 10.1093/nar/gkf496] [Citation(s) in RCA: 210] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The response of eukaryotic cells to the formation of a double-strand break (DSB) in chromosomal DNA is highly conserved. One of the earliest responses to DSB formation is phosphorylation of the C-terminal tail of H2A histones located in nucleosomes near the break. Histone variant H2AX and core histone H2A are phosphorylated in mammals and budding yeast, respectively. We demonstrate the DSB-induced phosphorylation of histone variant H2Av in Drosophila melanogaster. H2Av is a member of the H2AZ family of histone variants. Ser137 within an SQ motif located near the C- terminus of H2Av was phosphorylated in response to gamma-irradiation in both tissue culture cells and larvae. Phosphorylation was detected within 1 min of irradiation and detectable after only 0.3 Gy of radiation exposure. Photochemically induced DSBs, but not general oxidative damage or UV-induced nicking of DNA, caused H2Av phosphorylation, suggesting that phosphorylation is DSB specific. Imaginal disc cells from Drosophila expressing a mutant allele of H2Av with its C-terminal tail deleted, and therefore unable to be phosphorylated, were more sensitive to radiation-induced apoptosis than were wildtype controls, suggesting that phosphorylation of H2Av is important for repair of radiation-induced DSBs. These observations suggest that in addition to providing the function of an H2AZ histone, H2Av is also the functional homolog in Drosophila of H2AX.
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Affiliation(s)
- James P Madigan
- Wadsworth Center, New York State Department of Health, State University of New York, Albany, NY 12201-2002, USA
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34
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Abbott DW, Ivanova VS, Wang X, Bonner WM, Ausió J. Characterization of the stability and folding of H2A.Z chromatin particles: implications for transcriptional activation. J Biol Chem 2001; 276:41945-9. [PMID: 11551971 DOI: 10.1074/jbc.m108217200] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
H2A.Z and H2A.1 nucleosome core particles and oligonucleosome arrays were obtained using recombinant versions of these histones and a native histone H2B/H3/H4 complement reconstituted onto appropriate DNA templates. Analysis of the reconstituted nucleosome core particles using native polyacrylamide gel electrophoresis and DNase I footprinting showed that H2A.Z nucleosome core particles were almost structurally indistinguishable from its H2A.1 or native chicken erythrocyte counterparts. While this result is in good agreement with the recently published crystallographic structure of the H2A.Z nucleosome core particle (Suto, R. K., Clarkson, M J., Tremethick, D. J., and Luger, K. (2000) Nat. Struct. Biol. 7, 1121-1124), the ionic strength dependence of the sedimentation coefficient of these particles exhibits a substantial destabilization, which is most likely the result of the histone H2A.Z-H2B dimer binding less tightly to the nucleosome. Analytical ultracentrifuge analysis of the H2A.Z 208-12, a DNA template consisting of 12 tandem repeats of a 208-base pair sequence derived from the sea urchin Lytechinus variegatus 5 S rRNA gene, reconstituted oligonucleosome complexes in the absence of histone H1 shows that their NaCl-dependent folding ability is significantly reduced. These results support the notion that the histone H2A.Z variant may play a chromatin-destabilizing role, which may be important for transcriptional activation.
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Affiliation(s)
- D W Abbott
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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35
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Saint R, Clarkson M. Pictures in cell biology. A functional marker for Drosophila chromosomes in vivo. Trends Cell Biol 2000; 10:553. [PMID: 11121748 DOI: 10.1016/s0962-8924(00)01875-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- R Saint
- Centre for the Molecular Genetics of Development and Dept of Molecular Biosciences, University of Adelaide, SA 5005, Adelaide, Australia.
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36
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Santisteban MS, Kalashnikova T, Smith MM. Histone H2A.Z regulats transcription and is partially redundant with nucleosome remodeling complexes. Cell 2000; 103:411-22. [PMID: 11081628 DOI: 10.1016/s0092-8674(00)00133-1] [Citation(s) in RCA: 252] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Nucleosomes impose a block to transcription that can be overcome in vivo by remodeling complexes such as SNF/SWI and histone modification complexes such as SAGA. Mutations in the major core histones relieve transcriptional repression and bypass the requirement for SNF/SWI and SAGA. We have found that the variant histone H2A.Z regulates gene transcription, and deletion of the gene encoding H2A.Z strongly increases the requirement for SNF/SWI and SAGA. This synthetic genetic interaction is seen at the level of single genes and acts downstream of promoter nucleosome reorganization. H2A.Z is preferentially crosslinked in vivo to intergenic DNA at the PH05 and GAL1 loci, and this association changes with transcriptional activation. These results describe a novel pathway for regulating transcription using variant histones to modulate chromatin structure.
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MESH Headings
- Adenosine Triphosphatases
- Alleles
- Chromosomal Proteins, Non-Histone/genetics
- Chromosomal Proteins, Non-Histone/physiology
- DNA, Fungal/genetics
- DNA, Fungal/metabolism
- DNA, Intergenic/genetics
- DNA, Intergenic/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- DNA-Binding Proteins/physiology
- Fungal Proteins/genetics
- Fungal Proteins/physiology
- Gene Deletion
- Gene Expression Regulation, Fungal
- Genes, Essential/genetics
- Genes, Fungal/genetics
- Genes, Fungal/physiology
- Histones/chemistry
- Histones/genetics
- Histones/metabolism
- Hot Temperature
- Macromolecular Substances
- Membrane Transport Proteins/genetics
- Molecular Conformation
- Nuclear Proteins
- Nucleosomes/chemistry
- Nucleosomes/genetics
- Nucleosomes/metabolism
- Phenotype
- Phosphate Transport Proteins
- Promoter Regions, Genetic/genetics
- Protein Binding
- Protein Kinases/genetics
- Protein Kinases/physiology
- Protein Subunits
- Recombinant Fusion Proteins
- Saccharomyces cerevisiae/cytology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae Proteins
- Suppression, Genetic/genetics
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription, Genetic
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Affiliation(s)
- M S Santisteban
- Department of Microbiology and Cancer Center, University of Virginia, Charlottesville 22908, USA
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37
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Clarkson M, Saint R. A His2AvDGFP fusion gene complements a lethal His2AvD mutant allele and provides an in vivo marker for Drosophila chromosome behavior. DNA Cell Biol 1999; 18:457-62. [PMID: 10390154 DOI: 10.1089/104454999315178] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have generated Drosophila melanogaster lines carrying a modified genomic fragment which encodes the D. melanogaster variant H2A.F/Z class histone, His2AvD, fused to the green fluorescent protein (GFP) of the jellyfish Aequorea victoria. We show here that the fusion protein consists of functional GFP and functional histone His2AvD. The His2AvD portion of the fusion gene was shown to be functional by rescue of His2AvD mutant lethality. Fluorescence of the fusion protein in vivo was observed in embryonic cleavage stage interphase nuclei and on chromosomes as early as cycle 9, correlating with activation of transcription. Unlike transcription factors, the His2AvDGFP protein remained on transcriptionally inactive chromosomes throughout mitosis. Subsequently, fluorescence was observed in nuclei at all stages of embryonic and larval development and in adult somatic tissues, consistent with the distribution of His2AvD observed by immunohistochemical staining. This functional fusion histone acts as an excellent in vivo marker for chromosomes and chromosome behavior and, given the ability of the fusion gene to prevent null-mutant lethality, without disrupting normal cellular functions. The very high level of conservation of the H2A.F/Z family of variant histones suggests that the equivalent fusion protein construct should function equally well in a wide range of organisms.
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Affiliation(s)
- M Clarkson
- Department of Biochemistry, University of Adelaide, SA, Australia
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38
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Akhmanova A, Hennig W. Drosophila melanogaster histone H2B retropseudogene is inserted into a region rich in transposable elements. Genome 1998; 41:396-401. [PMID: 9729774 DOI: 10.1139/g98-035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have isolated and characterized the genomic sequence of a Drosophila melanogaster histone H2B pseudogene that is localized outside of the cluster of the replication-dependent histone genes and has all the properties of a retropseudogene. It is highly homologous to the transcribed region of the D. melanogaster histone H2B gene, but not to its flanking regions, and is surrounded by short direct repeats. The pseudogene contains several point mutations that preclude its translation. The sequence of the 3' region of this pseudogene is compatible with the hypothesis that the 3' terminal stem-loop structure of the histone H2B mRNA has served as a primer for the reverse transcription event from which this pseudogene originated. Analysis of the regions flanking the histone H2B pseudogene revealed the presence of three different types of transposable elements, suggesting that this chromosomal locus represents a hotspot for transposition.
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Affiliation(s)
- A Akhmanova
- Department of Physiological Chemistry and Pathobiochemistry, Johannes Gutenberg-Universität, Mainz, Germany
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39
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Jiang W, Guo X, Bhavanandan VP. Histone H2A.F/Z subfamily: the smallest member and the signature sequence. Biochem Biophys Res Commun 1998; 245:613-7. [PMID: 9571203 DOI: 10.1006/bbrc.1998.8495] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The nucleotide sequence of a 700 basepair cDNA obtained from rabbit bladder was determined. It encodes a 123 amino acid protein, which is the smallest member of histone H2A.F/Z subfamily. The known H2A.F/Z variants are highly conserved in their central core regions of about 100 amino acids but more divergent in their N- and C-terminal ends. In addition to the seven amino acid signature sequence previously known for the H2A proteins, all the cloned H2A.F/Z variants contain an identical peptide sequence, L-E-Y-L-T-A-E-V-L-E-L-A-G-N-A. This 15 amino acid motif is proposed here as the signature sequence to identify new members of the H2A.F/Z subfamily.
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Affiliation(s)
- W Jiang
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey 17033, USA.
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40
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41
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Tittawella I, Ljungkvist A, Kimdal M. The gene for histone H2A from the insect trypanosome Crithidia fasciculata. Mol Biochem Parasitol 1997; 88:259-62. [PMID: 9274887 DOI: 10.1016/s0166-6851(97)00080-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- I Tittawella
- Department of Cell and Molecular Biology, University of Umeå, Sweden.
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42
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Mandl B, Brandt WF, Superti-Furga G, Graninger PG, Birnstiel ML, Busslinger M. The five cleavage-stage (CS) histones of the sea urchin are encoded by a maternally expressed family of replacement histone genes: functional equivalence of the CS H1 and frog H1M (B4) proteins. Mol Cell Biol 1997; 17:1189-200. [PMID: 9032246 PMCID: PMC231844 DOI: 10.1128/mcb.17.3.1189] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The cleavage-stage (CS) histones of the sea urchin are known to be maternally expressed in the egg, have been implicated in chromatin remodeling of the male pronucleus following fertilization, and are the only histone variants present in embryonic chromatin up to the four-cell stage. With the help of partial peptide sequence information, we have isolated and identified CS H1, H2A, H2B, H3, and H4 cDNAs from egg poly(A)+ mRNA of the sea urchin Psammechinus miliaris. All five CS proteins correspond to replacement histone variants which are encoded by replication-independent genes containing introns, poly(A) addition signals, and long nontranslated sequences. Transcripts of the CS histone genes could be detected only during oogenesis and in development up to the early blastula stage. The CS proteins, with the exception of H4, are unique histones which are distantly related in sequence to the early, late, and sperm histone subtypes of the sea urchin. In contrast, the CS H1 protein displays highest sequence homology with the H1M (B4) histone of Xenopus laevis. Both H1 proteins are replacement histone variants with very similar developmental expression profiles in their respective species, thus indicating that the frog H1M (B4) gene is a vertebrate homolog of the CS H1 gene. These data furthermore suggest that the CS histones are of ancient evolutionary origin and may perform similar conserved functions during oogenesis and early development in different species.
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Affiliation(s)
- B Mandl
- Research Institute of Molecular Pathology, Vienna, Austria
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43
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Iouzalen N, Moreau J, Méchali M. H2A.ZI, a new variant histone expressed during Xenopus early development exhibits several distinct features from the core histone H2A. Nucleic Acids Res 1996; 24:3947-52. [PMID: 8918796 PMCID: PMC146197 DOI: 10.1093/nar/24.20.3947] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We have isolated from a subtractive cDNA library of Xenopus laevis a novel transcript, H2A.ZI, which belongs to the H2A.Z variant gene family. Characterization of its expression during oogenesis and development shows significant differences from the expression of the core histone H2A. First, H2A.ZI mRNA is mainly detected only during oogenesis and after the midblastula transition, whereas H2A is constitutively expressed, at much higher levels, throughout embryonic growth. Second, in contrast with H2A, the variant H2A.ZI is polyadenylated during development. Third, expression of H2A.ZI is uncoupled from the S phase after gastrula, whereas synthesis of the core histone H2A mRNA is tightly controlled to DNA replication. Interestingly, H2A.ZI is less charged in the N-terminal tail which is crucial for chromatin-mediated repression. The characteristics of H2A.ZI suggest that its incorporation into nucleosomes would lead to a chromatin structure more competent for gene expression during development.
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Affiliation(s)
- N Iouzalen
- Institut Jacques Monod, Molecular Embryology, Paris, France
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44
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Abstract
Although variants have been identified for every class of histone, their functions remain unknown. We have been studying the histone H2A variant hv1 in the ciliated protozoan Tetrahymena thermophila. Sequence analysis indicates that hv1 belongs to the H2A.F/Z type of histone variants. On the basis of the high degree of evolutionary conservation of this class of histones, they are proposed to have one or more distinct and essential functions that cannot be performed by their major H2A counterparts. Considerable evidence supports the hypothesis that the hv1 protein in T. thermophila and hv1-like proteins in other eukaryotes are associated with active chromatin. In T. thermophila, simple mass transformation and gene replacement techniques have recently become available. In this report, we demonstrate that either the HTA1 gene or the HTA2 gene, encoding the major H2As, can be completely replaced by disrupted genes in the polyploid, transcriptionally active macronucleus, indicating that neither of the two genes is essential. However, only some of the HTA3 genes encoding hv1 can be replaced by disrupted genes, indicating that the H2A.F/Z type variants have an essential function that cannot be performed by the major H2A genes. Thus, an essential gene in T. thermophila can be defined by the fact that it can be partially, but not completely, eliminated from the polyploid macronucleus. To our knowledge, this study represents the first use of gene disruption technology to study core histone gene function in any organism other than yeast and the first demonstration of an essential gene in T. thermophila using these methods. When a rescuing plasmid carrying a wild-type HTA3 gene was introduced into the T. thermophila cells, the endogenous chromosomal HTA3 could be completely replaced, defining a gene replacement strategy that can be used to analyze the function of essential genes.
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Affiliation(s)
- X Liu
- Department of Biology, University of Rochester, New York 14627, USA
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45
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Akhmanova A, Miedema K, Hennig W. Identification and characterization of the Drosophila histone H4 replacement gene. FEBS Lett 1996; 388:219-22. [PMID: 8690091 DOI: 10.1016/0014-5793(96)00551-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Replacement variant genes for different histones have been described in most higher eukaryotes. However, so far no such gene has been found for histone H4. We have isolated from both Drosophila melanogaster and D. hydei a novel histone H4 encoding gene, H4r, which displays all the properties of a histone replacement variant gene: it contains introns, generates polyadenylated mRNA, represents the predominant H4 transcript in non-dividing tissues and is present in the genome as a single copy. The encoded polypeptide is identical to the Drosophila cell-cycle regulated histone H4. The fact that it is a single copy gene makes it prone to genetic analysis and it might be a useful tool for studying nucleosome structure and function.
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Affiliation(s)
- A Akhmanova
- Department of Molecular and Developmental Genetics, Faculty of Sciences, Catholic University of Nijmegen, The Netherlands
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46
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Liu X, Bowen J, Gorovsky MA. Either of the major H2A genes but not an evolutionarily conserved H2A.F/Z variant of Tetrahymena thermophila can function as the sole H2A gene in the yeast Saccharomyces cerevisiae. Mol Cell Biol 1996; 16:2878-87. [PMID: 8649398 PMCID: PMC231281 DOI: 10.1128/mcb.16.6.2878] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
H2A.F/Z histones are conserved variants that diverged from major H2A proteins early in evolution, suggesting they perform an important function distinct from major H2A proteins. Antisera specific for hv1, the H2A.F/Z variant of the ciliated protozoan Tetrahymena thermophila, cross-react with proteins from Saccharomyces cerevisiae. However, no H2A.F/Z variant has been reported in this budding yeast species. We sought to distinguish among three explanations for these observations: (i) that S. cerevisiae has an undiscovered H2A.F/Z variant, (ii) that the major S. cerevisiae H2A proteins are functionally equivalent to H2A.F/Z variants, or (iii) that the conserved epitope is found on a non-H2A molecule. Repeated attempts to clone an S. cerevisiae hv1 homolog only resulted in the cloning of the known H2A genes yHTA1 and yHTA2. To test for functional relatedness, we attempted to rescue strains lacking the yeast H2A genes with either the Tetrahymena major H2A genes (tHTA1 or tHTA2) or the gene (tHTA3) encoding hv1. Although they differ considerably in sequence from the yeast H2A genes, the major Tetrahymena H2A genes can provide the essential functions of H2A in yeast cells, the first such case of trans-species complementation of histone function. The Tetrahymena H2A genes confer a cold-sensitive phenotype. Although expressed at high levels and transported to the nucleus, hv1 cannot replace yeast H2A proteins. Proteins from S. cerevisiae strains lacking yeast H2A genes fail to cross-react with anti-hv1 antibodies. These studies make it likely that S. cerevisiae differs from most other eukaryotes in that it does not have an H2A.F/Z homolog. A hypothesis is presented relating the absence of H2A.F/Z in S. cerevisiae to its function in other organisms.
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Affiliation(s)
- X Liu
- Department of Biology, University of Rochester, New York 14627, USA
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47
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Hatch CL, Bonner WM. An upstream region of the H2AZ gene promoter modulates promoter activity in different cell types. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1305:59-62. [PMID: 8605251 DOI: 10.1016/0167-4781(95)00223-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Human H2AZ gene promoter fragments that included sequences upstream from the core promoter resulted in decreased activity of reporter constructs transfected into several human cell lines, but increased activity in the undifferentiated human embryonal carcinoma cell line Tera-2. Differentiation of Tera-2 cells in media containing retinoic acid restored the ability of the upstream region to downregulate H2AZ gene promoter activity. Levels of endogenous H2AZ mRNA were also found to be 2.5-fold higher in undifferentiated Tera-2 cells than in differentiated Tera-2 cells. A 128 bp region located 234 to 361 bp upstream from the transcription start site of the H2AZ gene was found to be responsible for the modulation of reporter activity. The upstream region also functioned similarly when removed from the H2AZ gene promoter and inserted upstream of the SV40 promoter in reporter constructs. Gel mobility shift studies of fragments of this region revealed two sequence elements, CTCCTCC and CACGTG, that bound nuclear factors in vitro.
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Affiliation(s)
- C L Hatch
- Laboratory of Molecular Pharmacology, DTP, DCT, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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48
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Carr AM, Dorrington SM, Hindley J, Phear GA, Aves SJ, Nurse P. Analysis of a histone H2A variant from fission yeast: evidence for a role in chromosome stability. MOLECULAR & GENERAL GENETICS : MGG 1994; 245:628-35. [PMID: 7808414 DOI: 10.1007/bf00282226] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have isolated and characterised the pht1 gene from the fission yeast Schizosaccharomyces pombe. The sequence of the predicted translation product has revealed a striking similarity to the family of H2A.F/Z histone variant proteins, which have been found in a variety of different organisms. Cells deleted for the pht1 gene locus grow slowly, exhibit an altered colony morphology, increased resistance to heat shock and show a significant decrease in the fidelity of segregation of an S. pombe minichromosome. We propose that the histone H2A variant encoded by the pht1 gene is important for chromosomal structure and function, possibly including a role in controlling the fidelity of chromosomal segregation during mitosis.
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Affiliation(s)
- A M Carr
- Imperial Cancer Research Fund, London, UK
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49
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Puerta C, Martin J, Alonso C, López MC. Isolation and characterization of the gene encoding histone H2A from Trypanosoma cruzi. Mol Biochem Parasitol 1994; 64:1-10. [PMID: 8078513 DOI: 10.1016/0166-6851(94)90129-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In the present paper we report the isolation and characterization of the sequence of two genomic DNA fragments coding for the histone H2A of Trypanosoma cruzi. An analysis of the predicted amino acid sequence shows the presence of the amino-terminal motif characteristic of the H2A histones proteins and the Lys-Lys motif reported to be the site for the ubiquitin attachment. Southern blots of total parasite DNA probed with the H2A sequence suggested that the T. cruzi histone H2A gene is encoded in two independent gene clusters. The molecular karyotyping of the parasite indicated that these two clusters locate in a single chromosome of about 700 kb in length. The T. cruzi H2A mRNA is polyadenylated as are the basal histone mRNAs of higher eukaryotes and the histone mRNAs of yeast. By polymerase chain reaction amplification and sequencing and by S1 mapping we determined respectively the 5' and 3' end of the gene showing that the miniexon is added to the mRNA 71 nucleotides upstream of the ATG initiation codon and that the polyadenylation site locates in nucleotide position 773-775 close to invert repeats.
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Affiliation(s)
- C Puerta
- Instituto de Parasitologia y Biomedicina, Consejo Superior de Investigaciones Científicas, Granada, Spain
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Li W, Nagaraja S, Delcuve GP, Hendzel MJ, Davie JR. Effects of histone acetylation, ubiquitination and variants on nucleosome stability. Biochem J 1993; 296 ( Pt 3):737-44. [PMID: 8280071 PMCID: PMC1137757 DOI: 10.1042/bj2960737] [Citation(s) in RCA: 90] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The properties of the nucleosomes of a salt-soluble, transcriptionally active gene-enriched fraction of chicken erythrocyte chromatin were evaluated by hydroxyapatite dissociation chromatography. We have demonstrated previously that the salt-soluble, transcriptionally active gene-enriched polynucleosomes are enriched in dynamically acetylated and ubiquitinated histones, and in an atypical U-shaped nucleosome that possessed about 20% less protein than a typical nucleosome. Further, newly synthesized histones H2A and H2B exchange preferentially with the nucleosomal histones H2A and H2B of this salt-soluble chromatin fraction. Analysis of the histones eluting from the hydroxyapatite-bound chromatin demonstrated that hyperacetylated and ubiquitinated (u), including multi-ubiquitinated, H2A-H2B.1 dimers dissociated at lower concentrations of NaCl than unmodified dimers or dimers with histone variants H2A.Z and/or H2B.2. Cross-linking studies revealed that at least 50% of uH2B.1 was paired with uH2A. uH2A-uH2B.1 dimers dissociated at lower NaCl concentrations than H2A-uH2B.1 dimers. Hyperacetylated histone (H3-H4)2 tetramers also eluted at lower concentrations of NaCl than unmodified tetramers. Our results support the idea that acetylation and ubiquitination of histones H2A and H2B.1 increase the lability of H2A-H2B.1 dimers in transcriptionally active nucleosomes. In contrast, our observations suggest that histone variants H2A.Z and H2B.2. stabilize the association of the H2A-H2B dimer in nucleosomes. The elevated lability of the H2A-H2B dimer may facilitate processes such as the exchange of these dimers with newly synthesized histones, the elongation process of transcription and transcription factor binding.
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Affiliation(s)
- W Li
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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