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Makki R, Meller VH. Identification of X chromatin is modulated by complementary pathways in Drosophila melanogaster. G3 (BETHESDA, MD.) 2024; 14:jkae057. [PMID: 38491905 PMCID: PMC11152068 DOI: 10.1093/g3journal/jkae057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/04/2023] [Accepted: 03/01/2024] [Indexed: 03/18/2024]
Abstract
Drosophila melanogaster males have one X chromosome while females have two. This creates an imbalance in X:A gene dosage between the sexes. This imbalance is corrected by increasing transcription from male X-linked genes approximately 2-fold. This process involves the Male-Specific Lethal (MSL) complex, which is recruited to Chromatin Entry Sites (CES) and transcribed X-linked genes, where it modifies chromatin to increase expression. Repetitive sequences strikingly enriched in X euchromatin, the 1.688X satellite repeats, also promote recruitment of the MSL complex to nearby genes. Unlike CES, the 1.688X repeats do not recruit the MSL complex directly. The genetic architecture of recruitment by these DNA elements remains speculative. To facilitate dissection of the mechanism of recruitment, we developed a luciferase reporter system for recruitment of compensation to an autosome. The system was validated by knock down of genes known to participate in compensation. Knock down of factors genetically linked to X recognition reveals that 1.688X repeats recruit through a different mechanism than the CES. Our findings suggest that 1.688X repeats play a larger role during embryogenesis, whereas the contribution of 1.688X repeats and CES is equivalent later in development. Our studies also reveal unexpected complexity and potential interdependence of recruiting elements.
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Affiliation(s)
- Reem Makki
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA
| | - Victoria H Meller
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48202, USA
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2
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Jayakrishnan M, Havlová M, Veverka V, Regnard C, Becker PB. Genomic context-dependent histone H3K36 methylation by three Drosophila methyltransferases and implications for dedicated chromatin readers. Nucleic Acids Res 2024:gkae449. [PMID: 38813825 DOI: 10.1093/nar/gkae449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/03/2024] [Accepted: 05/28/2024] [Indexed: 05/31/2024] Open
Abstract
Methylation of histone H3 at lysine 36 (H3K36me3) marks active chromatin. The mark is interpreted by epigenetic readers that assist transcription and safeguard the integrity of the chromatin fiber. The chromodomain protein MSL3 binds H3K36me3 to target X-chromosomal genes in male Drosophila for dosage compensation. The PWWP-domain protein JASPer recruits the JIL1 kinase to active chromatin on all chromosomes. Unexpectedly, depletion of K36me3 had variable, locus-specific effects on the interactions of those readers. This observation motivated a systematic and comprehensive study of K36 methylation in a defined cellular model. Contrasting prevailing models, we found that K36me1, K36me2 and K36me3 each contribute to distinct chromatin states. A gene-centric view of the changing K36 methylation landscape upon depletion of the three methyltransferases Set2, NSD and Ash1 revealed local, context-specific methylation signatures. Set2 catalyzes K36me3 predominantly at transcriptionally active euchromatin. NSD places K36me2/3 at defined loci within pericentric heterochromatin and on weakly transcribed euchromatic genes. Ash1 deposits K36me1 at regions with enhancer signatures. The genome-wide mapping of MSL3 and JASPer suggested that they bind K36me2 in addition to K36me3, which was confirmed by direct affinity measurement. This dual specificity attracts the readers to a broader range of chromosomal locations and increases the robustness of their actions.
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Affiliation(s)
- Muhunden Jayakrishnan
- Biomedical Center, Molecular Biology Division, Ludwig-Maximilians-Universität, Munich, Germany
| | - Magdalena Havlová
- Institute of Organic Chemistry and Biochemistry (IOCB) of the Czech Academy of Sciences, Prague, Czech Republic
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry (IOCB) of the Czech Academy of Sciences, Prague, Czech Republic
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Catherine Regnard
- Biomedical Center, Molecular Biology Division, Ludwig-Maximilians-Universität, Munich, Germany
| | - Peter B Becker
- Biomedical Center, Molecular Biology Division, Ludwig-Maximilians-Universität, Munich, Germany
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3
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Salzler HR, Vandadi V, Matera AG. Set2 and H3K36 regulate the Drosophila male X chromosome in a context-specific manner, independent from MSL complex spreading. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.03.592390. [PMID: 38766267 PMCID: PMC11100620 DOI: 10.1101/2024.05.03.592390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Dosage compensation in Drosophila involves upregulating male X-genes two-fold. This process is carried out by the MSL (male-specific lethal) complex, which binds high-affinity sites and spreads to surrounding genes. Current models of MSL spreading focus on interactions of MSL3 (male-specific lethal 3) with histone marks; in particular, Set2-dependent H3 lysine-36 trimethylation (H3K36me3). However, Set2 might affect DC via another target, or there could be redundancy between canonical H3.2 and variant H3.3 histones. Further, it is difficult to parse male-specific effects from those that are simply X-specific. To discriminate among these possibilities, we employed genomic approaches in H3K36 (residue) and Set2 (writer) mutants. The results confirm a role for Set2 in X-gene regulation, but show that expression trends in males are often mirrored in females. Instead of global male-specific reduction of X-genes in Set2/H3K36 mutants, the effects were heterogeneous. We identified cohorts of genes whose expression was significantly altered following loss of H3K36 or Set2, but the changes were in opposite directions, suggesting that H3K36me states have reciprocal functions. In contrast to H4K16R controls, analysis of combined H3.2K36R/H3.3K36R mutants neither showed consistent reduction in X-gene expression, nor any correlation with MSL3 binding. Examination of other developmental stages/tissues revealed additional layers of context-dependence. Our studies implicate BEAF-32 and other insulator proteins in Set2/H3K36-dependent regulation. Overall, the data are inconsistent with the prevailing model wherein H3K36me3 directly recruits the MSL complex. We propose that Set2 and H3K36 support DC indirectly, via processes that are utilized by MSL but common to both sexes.
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Affiliation(s)
- Harmony R. Salzler
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
| | - Vasudha Vandadi
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
| | - A. Gregory Matera
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
- RNA Discovery and Lineberger Comprehensive Cancer Centers, University of North Carolina, Chapel Hill, NC, USA
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4
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Mitchell T, Lin J, Hicks S, James J, Rangan P, Forni P. Loss of function of male-specific lethal 3 (Msl3) does not affect spermatogenesis in rodents. Dev Dyn 2024; 253:453-466. [PMID: 37847071 PMCID: PMC11021377 DOI: 10.1002/dvdy.669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/12/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Male-specific lethal 3 (Msl3) is a member of the chromatin-associated male-specific lethal MSL complex, which is responsible for the transcriptional upregulation of genes on the X chromosome in males of Drosophila. Although the dosage complex operates differently in mammals, the Msl3 gene is conserved from flies to humans. Msl3 is required for meiotic entry during Drosophila oogenesis. Recent reports indicate that also in primates, Msl3 is expressed in undifferentiated germline cells before meiotic entry. However, if Msl3 plays a role in the meiotic entry of mammals has yet to be explored. RESULTS To understand, if Msl3a plays a role in the meiotic entry of mammals, we used mouse spermatogenesis as a study model. Analyses of single-cell RNA-seq data revealed that, in mice, Msl3 is mostly expressed in meiotic cells. To test the role of Msl3 in meiosis, we used a male germline-specific Stra8-iCre driver and a newly generated Msl3flox conditional knock-out mouse line. Msl3 conditional loss-of-function in spermatogonia did not cause spermatogenesis defects or changes in the expression of genes related to meiosis. CONCLUSIONS Our data suggest that, in mice, Msl3 exhibits delayed expression compared to Drosophila and primates, and loss-of-function mutations disrupting the chromodomain of Msl3 alone do not impede meiotic entry in rodents.
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Affiliation(s)
- T.A. Mitchell
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- The Center for Neuroscience Research, University at Albany, State University of New York, Albany, NY 12222, USA
| | - J.M. Lin
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- The Center for Neuroscience Research, University at Albany, State University of New York, Albany, NY 12222, USA
| | - S.M. Hicks
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - J.R. James
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - P. Rangan
- Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - P.E. Forni
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
- The Center for Neuroscience Research, University at Albany, State University of New York, Albany, NY 12222, USA
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5
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Brockett JS, Manalo T, Zein-Sabatto H, Lee J, Fang J, Chu P, Feng H, Patil D, Davidson P, Ogan K, Master VA, Pattaras JG, Roberts DL, Bergquist SH, Reyna MA, Petros JA, Lerit DA, Arnold RS. A missense SNP in the tumor suppressor SETD2 reduces H3K36me3 and mitotic spindle integrity in Drosophila. Genetics 2024; 226:iyae015. [PMID: 38290049 PMCID: PMC10990431 DOI: 10.1093/genetics/iyae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 02/01/2024] Open
Abstract
Mutations in SETD2 are among the most prevalent drivers of renal cell carcinoma (RCC). We identified a novel single nucleotide polymorphism (SNP) in SETD2, E902Q, within a subset of RCC patients, which manifests as both an inherited or tumor-associated somatic mutation. To determine if the SNP is biologically functional, we used CRISPR-based genome editing to generate the orthologous mutation within the Drosophila melanogaster Set2 gene. In Drosophila, the homologous amino acid substitution, E741Q, reduces H3K36me3 levels comparable to Set2 knockdown, and this loss is rescued by reintroduction of a wild-type Set2 transgene. We similarly uncovered significant defects in spindle morphogenesis, consistent with the established role of SETD2 in methylating α-Tubulin during mitosis to regulate microtubule dynamics and maintain genome stability. These data indicate the Set2 E741Q SNP affects both histone methylation and spindle integrity. Moreover, this work further suggests the SETD2 E902Q SNP may hold clinical relevance.
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Affiliation(s)
- Jovan S Brockett
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Tad Manalo
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hala Zein-Sabatto
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jina Lee
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Junnan Fang
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Philip Chu
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Harry Feng
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Dattatraya Patil
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Priscilla Davidson
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Kenneth Ogan
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Viraj A Master
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - John G Pattaras
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David L Roberts
- Emory University Department of Medicine, Division of General Internal Medicine, Atlanta, GA 30322, USA
| | - Sharon H Bergquist
- Emory University Department of Medicine, Division of General Internal Medicine, Atlanta, GA 30322, USA
| | - Matthew A Reyna
- Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - John A Petros
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
| | - Dorothy A Lerit
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
| | - Rebecca S Arnold
- Department of Urology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
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6
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Wei KHC, Chatla K, Bachtrog D. Single-cell RNA-seq of Drosophila miranda testis reveals the evolution and trajectory of germline sex chromosome regulation. PLoS Biol 2024; 22:e3002605. [PMID: 38687805 PMCID: PMC11135767 DOI: 10.1371/journal.pbio.3002605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 05/29/2024] [Accepted: 03/27/2024] [Indexed: 05/02/2024] Open
Abstract
Although sex chromosomes have evolved from autosomes, they often have unusual regulatory regimes that are sex- and cell-type-specific such as dosage compensation (DC) and meiotic sex chromosome inactivation (MSCI). The molecular mechanisms and evolutionary forces driving these unique transcriptional programs are critical for genome evolution but have been, in the case of MSCI in Drosophila, subject to continuous debate. Here, we take advantage of the younger sex chromosomes in D. miranda (XR and the neo-X) to infer how former autosomes acquire sex-chromosome-specific regulatory programs using single-cell and bulk RNA sequencing and ribosome profiling, in a comparative evolutionary context. We show that contrary to mammals and worms, the X down-regulation through germline progression is most consistent with the shutdown of DC instead of MSCI, resulting in half gene dosage at the end of meiosis for all 3 X's. Moreover, lowly expressed germline and meiotic genes on the neo-X are ancestrally lowly expressed, instead of acquired suppression after sex linkage. For the young neo-X, DC is incomplete across all tissue and cell types and this dosage imbalance is rescued by contributions from Y-linked gametologs which produce transcripts that are translated to compensate both gene and protein dosage. We find an excess of previously autosomal testis genes becoming Y-specific, showing that the neo-Y and its masculinization likely resolve sexual antagonism. Multicopy neo-sex genes are predominantly expressed during meiotic stages of spermatogenesis, consistent with their amplification being driven to interfere with mendelian segregation. Altogether, this study reveals germline regulation of evolving sex chromosomes and elucidates the consequences these unique regulatory mechanisms have on the evolution of sex chromosome architecture.
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Affiliation(s)
- Kevin H-C. Wei
- Department of Integrative Biology, University of California Berkeley, Berkeley, California, United States of America
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kamalakar Chatla
- Department of Integrative Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Doris Bachtrog
- Department of Integrative Biology, University of California Berkeley, Berkeley, California, United States of America
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7
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Lindehell H, Schwartz YB, Larsson J. Methylation of lysine 36 on histone H3 is required to control transposon activities in somatic cells. Life Sci Alliance 2023; 6:e202201832. [PMID: 37169594 PMCID: PMC10176111 DOI: 10.26508/lsa.202201832] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 05/03/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023] Open
Abstract
Transposable elements constitute a substantial portion of most eukaryotic genomes and their activity can lead to developmental and neuronal defects. In the germline, transposon activity is antagonized by the PIWI-interacting RNA pathway tasked with repression of transposon transcription and degrading transcripts that have already been produced. However, most of the genes required for transposon control are not expressed outside the germline, prompting the question: what causes deleterious transposons activity in the soma and how is it managed? Here, we show that disruptions of the Histone 3 lysine 36 methylation machinery led to increased transposon transcription in Drosophila melanogaster brains and that there is division of labour for the repression of transposable elements between the different methyltransferases Set2, NSD, and Ash1. Furthermore, we show that disruption of methylation leads to somatic activation of key genes in the PIWI-interacting RNA pathway and the preferential production of RNA from dual-strand piRNA clusters.
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Affiliation(s)
| | - Yuri B Schwartz
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Jan Larsson
- Department of Molecular Biology, Umeå University, Umeå, Sweden
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8
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Cabrita B, Martinho RG. Genetic and Epigenetic Regulation of Drosophila Oocyte Determination. J Dev Biol 2023; 11:21. [PMID: 37367475 DOI: 10.3390/jdb11020021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 06/28/2023] Open
Abstract
Primary oocyte determination occurs in many organisms within a germ line cyst, a multicellular structure composed of interconnected germ cells. However, the structure of the cyst is itself highly diverse, which raises intriguing questions about the benefits of this stereotypical multicellular environment for female gametogenesis. Drosophila melanogaster is a well-studied model for female gametogenesis, and numerous genes and pathways critical for the determination and differentiation of a viable female gamete have been identified. This review provides an up-to-date overview of Drosophila oocyte determination, with a particular emphasis on the mechanisms that regulate germ line gene expression.
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Affiliation(s)
- Brigite Cabrita
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Agra do Crasto, Edifício 30, 3810-193 Aveiro, Portugal
| | - Rui Gonçalo Martinho
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Agra do Crasto, Edifício 30, 3810-193 Aveiro, Portugal
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9
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Dosage Compensation in Drosophila: Its Canonical and Non-Canonical Mechanisms. Int J Mol Sci 2022; 23:ijms231810976. [PMID: 36142884 PMCID: PMC9506574 DOI: 10.3390/ijms231810976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/17/2022] Open
Abstract
Dosage compensation equalizes gene expression in a single male X chromosome with that in the pairs of autosomes and female X chromosomes. In the fruit fly Drosophila, canonical dosage compensation is implemented by the male-specific lethal (MSL) complex functioning in all male somatic cells. This complex contains acetyl transferase males absent on the first (MOF), which performs H4K16 hyperacetylation specifically in the male X chromosome, thus facilitating transcription of the X-linked genes. However, accumulating evidence points to an existence of additional, non-canonical dosage compensation mechanisms operating in somatic and germline cells. In this review, we discuss current advances in the understanding of both canonical and non-canonical mechanisms of dosage compensation in Drosophila.
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10
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McCarthy A, Sarkar K, Martin ET, Upadhyay M, Jang S, Williams ND, Forni PE, Buszczak M, Rangan P. Msl3 promotes germline stem cell differentiation in female Drosophila. Development 2022; 149:dev199625. [PMID: 34878097 PMCID: PMC8783043 DOI: 10.1242/dev.199625] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 11/19/2021] [Indexed: 01/07/2023]
Abstract
Gamete formation from germline stem cells (GSCs) is essential for sexual reproduction. However, the regulation of GSC differentiation is incompletely understood. Set2, which deposits H3K36me3 modifications, is required for GSC differentiation during Drosophila oogenesis. We discovered that the H3K36me3 reader Male-specific lethal 3 (Msl3) and histone acetyltransferase complex Ada2a-containing (ATAC) cooperate with Set2 to regulate GSC differentiation in female Drosophila. Msl3, acting independently of the rest of the male-specific lethal complex, promotes transcription of genes, including a germline-enriched ribosomal protein S19 paralog RpS19b. RpS19b upregulation is required for translation of RNA-binding Fox protein 1 (Rbfox1), a known meiotic cell cycle entry factor. Thus, Msl3 regulates GSC differentiation by modulating translation of a key factor that promotes transition to an oocyte fate.
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Affiliation(s)
- Alicia McCarthy
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Kahini Sarkar
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Elliot T. Martin
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Maitreyi Upadhyay
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Seoyeon Jang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nathan D. Williams
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Paolo E. Forni
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Prashanth Rangan
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
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11
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Jurkowska RZ, Jeltsch A. Enzymology of Mammalian DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1389:69-110. [DOI: 10.1007/978-3-031-11454-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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12
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When Down Is Up: Heterochromatin, Nuclear Organization and X Upregulation. Cells 2021; 10:cells10123416. [PMID: 34943924 PMCID: PMC8700316 DOI: 10.3390/cells10123416] [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: 10/31/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022] Open
Abstract
Organisms with highly differentiated sex chromosomes face an imbalance in X-linked gene dosage. Male Drosophila solve this problem by increasing expression from virtually every gene on their single X chromosome, a process known as dosage compensation. This involves a ribonucleoprotein complex that is recruited to active, X-linked genes to remodel chromatin and increase expression. Interestingly, the male X chromosome is also enriched for several proteins associated with heterochromatin. Furthermore, the polytenized male X is selectively disrupted by the loss of factors involved in repression, silencing, heterochromatin formation or chromatin remodeling. Mutations in many of these factors preferentially reduce male survival or enhance the lethality of mutations that prevent normal recognition of the X chromosome. The involvement of primarily repressive factors in a process that elevates expression has long been puzzling. Interestingly, recent work suggests that the siRNA pathway, often associated with heterochromatin formation and repression, also helps the dosage compensation machinery identify the X chromosome. In light of this finding, we revisit the evidence that links nuclear organization and heterochromatin to regulation of the male X chromosome.
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13
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Lindehell H, Glotov A, Dorafshan E, Schwartz YB, Larsson J. The role of H3K36 methylation and associated methyltransferases in chromosome-specific gene regulation. SCIENCE ADVANCES 2021; 7:eabh4390. [PMID: 34597135 PMCID: PMC10938550 DOI: 10.1126/sciadv.abh4390] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
In Drosophila, two chromosomes require special mechanisms to balance their transcriptional output to the rest of the genome. These are the male-specific lethal complex targeting the male X chromosome and Painting of fourth targeting chromosome 4. Here, we explore the role of histone H3 methylated at lysine-36 (H3K36) and the associated methyltransferases—Set2, NSD, and Ash1—in these two chromosome-specific systems. We show that the loss of Set2 impairs the MSL complex–mediated dosage compensation; however, the effect is not recapitulated by H3K36 replacement and indicates an alternative target of Set2. Unexpectedly, balanced transcriptional output from the fourth chromosome requires intact H3K36 and depends on the additive functions of NSD and Ash1. We conclude that H3K36 methylation and the associated methyltransferases are important factors to balance transcriptional output of the male X chromosome and the fourth chromosome. Furthermore, our study highlights the pleiotropic effects of these enzymes.
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Affiliation(s)
- Henrik Lindehell
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
| | - Alexander Glotov
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
| | - Eshagh Dorafshan
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
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14
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Rieder LE, Jordan WT, Larschan EN. Targeting of the Dosage-Compensated Male X-Chromosome during Early Drosophila Development. Cell Rep 2020; 29:4268-4275.e2. [PMID: 31875538 PMCID: PMC6952266 DOI: 10.1016/j.celrep.2019.11.095] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/02/2019] [Accepted: 11/22/2019] [Indexed: 12/15/2022] Open
Abstract
Dosage compensation, which corrects for the imbalance in X-linked gene expression between XX females and XY males, represents a model for how genes are targeted for coordinated regulation. However, the mechanism by which dosage compensation complexes identify the X chromosome during early development remains unknown because of the difficulty of sexing embryos before zygotic transcription using X- or Y-linked reporter transgenes. We used meiotic drive to sex Drosophila embryos before zygotic transcription and ChIP-seq to measure the dynamics of dosage compensation factor targeting. The Drosophila male-specific lethal dosage compensation complex (MSLc) requires the ubiquitous zinc-finger protein chromatin-linked adaptor for MSL proteins (CLAMP) to identify the X chromosome. We observe a multi-stage process in which MSLc first identifies CLAMP binding sites throughout the genome, followed by concentration at the strongest X-linked MSLc sites. We provide insight into the dynamics of binding site recognition by a large transcription complex during early development. Rieder et al. establish a meiotic drive system to study Drosophila X chromosome dosage compensation before the maternal-zygotic transition. This study uncovers another step in the process during which the dosage compensation complex identifies binding sites genome-wide before becoming enriched on the X chromosome.
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Affiliation(s)
| | - William Thomas Jordan
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Erica Nicole Larschan
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown University, Providence, RI 02912, USA.
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15
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An Z, Yin L, Liu Y, Peng M, Shen WH, Dong A. The histone methylation readers MRG1/MRG2 and the histone chaperones NRP1/NRP2 associate in fine-tuning Arabidopsis flowering time. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1010-1024. [PMID: 32324922 DOI: 10.1111/tpj.14780] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
Histones are highly basic proteins involved in packaging DNA into chromatin, and histone modifications are fundamental in epigenetic regulation in eukaryotes. Among the numerous chromatin modifiers identified in Arabidopsis (Arabidopsis thaliana), MORF-RELATED GENE (MRG)1 and MRG2 have redundant functions in reading histone H3 lysine 36 trimethylation (H3K36me3). Here, we show that MRG2 binds histone chaperones belonging to the NUCLEOSOME ASSEMBLY PROTEIN 1 (NAP1) family, including NAP1-RELATED PROTEIN (NRP)1 and NRP2. Characterization of the loss-of-function mutants mrg1 mrg2, nrp1 nrp2 and mrg1 mrg2 nrp1 nrp2 revealed that MRG1/MRG2 and NRP1/NRP2 regulate flowering time through fine-tuning transcription of floral genes by distinct molecular mechanisms. In particular, the physical interaction between NRP1/NRP2 and MRG1/MRG2 inhibited the binding of MRG1/MRG2 to the transcription factor CONSTANS (CO), leading to a transcriptional repression of FLOWERING LOCUS T (FT) through impeded H4K5 acetylation (H4K5ac) within the FT chromatin. By contrast, NRP1/NRP2 and MRG1/MRG2 act together, likely in a multiprotein complex manner, in promoting the transcription of FLOWERING LOCUS C (FLC) via an increase of both H4K5ac and H3K9ac in the FLC chromatin. Because the expression pattern of FLC represents the major category of differentially expressed genes identified by genome-wide RNA-sequencing analysis in the mrg1 mrg2, nrp1 nrp2 and mrg1 mrg2 nrp1 nrp2 mutants, it is reasonable to speculate that the NRP1/NRP2-MRG1/MRG2 complex may be involved in transcriptional activation of genes beyond FLC and flowering time control.
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Affiliation(s)
- Zengxuan An
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Liufan Yin
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yuhao Liu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Maolin Peng
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Wen-Hui Shen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
- Universitè de Strasbourg, CNRS, IBMP UPR 2357, Strasbourg, F-67000, France
| | - Aiwu Dong
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Department of Biochemistry, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
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16
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Machyna M, Kiefer L, Simon MD. Enhanced nucleotide chemistry and toehold nanotechnology reveals lncRNA spreading on chromatin. Nat Struct Mol Biol 2020; 27:297-304. [PMID: 32157249 DOI: 10.1038/s41594-020-0390-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 01/31/2020] [Indexed: 12/12/2022]
Abstract
Understanding the targeting and spreading patterns of long non-coding RNAs (lncRNAs) on chromatin requires a technique that can detect both high-intensity binding sites and reveal genome-wide changes in spreading patterns with high precision and confidence. Here we determine lncRNA localization using biotinylated locked nucleic acid (LNA)-containing oligonucleotides with toehold architecture capable of hybridizing to target RNA through strand-exchange reaction. During hybridization, a protecting strand competitively displaces contaminating species, leading to highly specific RNA capture of individual RNAs. Analysis of Drosophila roX2 lncRNA using this approach revealed that heat shock, unlike the unfolded protein response, leads to reduced spreading of roX2 on the X chromosome, but surprisingly also to relocalization to sites on autosomes. Our results demonstrate that this improved hybridization capture approach can reveal previously uncharacterized changes in the targeting and spreading of lncRNAs on chromatin.
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Affiliation(s)
- Martin Machyna
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA.,Chemical Biology Institute, Yale University, West Haven, CT, USA
| | - Lea Kiefer
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA.,Chemical Biology Institute, Yale University, West Haven, CT, USA
| | - Matthew D Simon
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA. .,Chemical Biology Institute, Yale University, West Haven, CT, USA.
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17
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Small Molecules Targeting the Specific Domains of Histone-Mark Readers in Cancer Therapy. Molecules 2020; 25:molecules25030578. [PMID: 32013155 PMCID: PMC7037402 DOI: 10.3390/molecules25030578] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 12/11/2022] Open
Abstract
Epigenetic modifications (or epigenetic tags) on DNA and histones not only alter the chromatin structure, but also provide a recognition platform for subsequent protein recruitment and enable them to acquire executive instructions to carry out specific intracellular biological processes. In cells, different epigenetic-tags on DNA and histones are often recognized by the specific domains in proteins (readers), such as bromodomain (BRD), chromodomain (CHD), plant homeodomain (PHD), Tudor domain, Pro-Trp-Trp-Pro (PWWP) domain and malignant brain tumor (MBT) domain. Recent accumulating data reveal that abnormal intracellular histone modifications (histone marks) caused by tumors can be modulated by small molecule-mediated changes in the activity of the above domains, suggesting that small molecules targeting histone-mark reader domains may be the trend of new anticancer drug development. Here, we summarize the protein domains involved in histone-mark recognition, and introduce recent research findings about small molecules targeting histone-mark readers in cancer therapy.
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18
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Zaghi M, Broccoli V, Sessa A. H3K36 Methylation in Neural Development and Associated Diseases. Front Genet 2020; 10:1291. [PMID: 31998360 PMCID: PMC6962298 DOI: 10.3389/fgene.2019.01291] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022] Open
Abstract
Post-translational methylation of H3 lysine 36 (H3K36) is an important epigenetic marker that majorly contributes to the functionality of the chromatin. This mark is interpreted by the cell in several crucial biological processes including gene transcription and DNA methylation. The homeostasis of H3K36 methylation is finely regulated by different enzyme classes which, when impaired, lead to a plethora of diseases; ranging from multi-organ syndromes to cancer, to pure neurological diseases often associated with brain development. This mini-review summarizes current knowledge on these important epigenetic signals with emphasis on the molecular mechanisms that (i) regulate their abundance, (ii) are influenced by H3K36 methylation, and (iii) the associated diseases.
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Affiliation(s)
- Mattia Zaghi
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Vania Broccoli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.,Concilio Nazionale Delle Ricerche (CNR), Instituto di Neuroscienze, Milan, Italy
| | - Alessandro Sessa
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
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19
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Demakova OV, Demakov SA, Boldyreva LV, Zykova TY, Levitsky VG, Semeshin VF, Pokholkova GV, Sidorenko DS, Goncharov FP, Belyaeva ES, Zhimulev IF. Faint gray bands in Drosophila melanogaster polytene chromosomes are formed by coding sequences of housekeeping genes. Chromosoma 2019; 129:25-44. [PMID: 31820086 DOI: 10.1007/s00412-019-00728-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 09/04/2019] [Accepted: 10/30/2019] [Indexed: 12/13/2022]
Abstract
In Drosophila melanogaster, the chromatin of interphase polytene chromosomes appears as alternating decondensed interbands and dense black or thin gray bands. Recently, we uncovered four principle chromatin states (4НММ model) in the fruit fly, and these were matched to the structures observed in polytene chromosomes. Ruby/malachite chromatin states form black bands containing developmental genes, whereas aquamarine chromatin corresponds to interbands enriched with 5' regions of ubiquitously expressed genes. Lazurite chromatin supposedly forms faint gray bands and encompasses the bodies of housekeeping genes. In this report, we test this idea using the X chromosome as the model and MSL1 as a protein marker of the lazurite chromatin. Our bioinformatic analysis indicates that in the X chromosome, it is only the lazurite chromatin that is simultaneously enriched for the proteins and histone marks associated with exons, transcription elongation, and dosage compensation. As a result of FISH and EM mapping of a dosage compensation complex subunit, MSL1, we for the first time provide direct evidence that lazurite chromatin forms faint gray bands. Our analysis proves that overall most of housekeeping genes typically span from the interbands (5' region of the gene) to the gray band (gene body). More rarely, active lazurite chromatin and inactive malachite/ruby chromatin may be found within a common band, where both the housekeeping and the developmental genes reside together.
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Affiliation(s)
- Olga V Demakova
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Sergey A Demakov
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Lidiya V Boldyreva
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Tatyana Yu Zykova
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Victor G Levitsky
- Novosibirsk State University, Novosibirsk, 630090, Russia.,Institute of Cytology and Genetics, SB RAS, 630090, Novosibirsk, Russia
| | - Valeriy F Semeshin
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Galina V Pokholkova
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Darya S Sidorenko
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Fedor P Goncharov
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Elena S Belyaeva
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Igor F Zhimulev
- Institute of Molecular and Cellular Biology, Siberian Branch of the Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia. .,Novosibirsk State University, Novosibirsk, 630090, Russia.
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20
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Tsurumi A, Xue S, Zhang L, Li J, Li WX. Genome-wide Kdm4 histone demethylase transcriptional regulation in Drosophila. Mol Genet Genomics 2019; 294:1107-1121. [PMID: 31020413 PMCID: PMC6813854 DOI: 10.1007/s00438-019-01561-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 04/03/2019] [Indexed: 12/23/2022]
Abstract
The histone lysine demethylase 4 (Kdm4/Jmjd2/Jhdm3) family is highly conserved across species and reverses di- and tri-methylation of histone H3 lysine 9 (H3K9) and lysine 36 (H3K36) at the N-terminal tail of the core histone H3 in various metazoan species including Drosophila, C.elegans, zebrafish, mice and humans. Previous studies have shown that the Kdm4 family plays a wide variety of important biological roles in different species, including development, oncogenesis and longevity by regulating transcription, DNA damage response and apoptosis. Only two functional Kdm4 family members have been identified in Drosophila, compared to five in mammals, thus providing a simple model system. Drosophila Kdm4 loss-of-function mutants do not survive past the early 2nd instar larvae stage and display a molting defect phenotype associated with deregulated ecdysone hormone receptor signaling. To further characterize and identify additional targets of Kdm4, we employed a genome-wide approach to investigate transcriptome alterations in Kdm4 mutants versus wild-type during early development. We found evidence of increased deregulated transcripts, presumably associated with a progressive accumulation of H3K9 and H3K36 methylation through development. Gene ontology analyses found significant enrichment of terms related to the ecdysteroid hormone signaling pathway important in development, as expected, and additionally previously unidentified potential targets that warrant further investigation. Since Kdm4 is highly conserved across species, our results may be applicable more widely to other organisms and our genome-wide dataset may serve as a useful resource for further studies.
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Affiliation(s)
- Amy Tsurumi
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, 50 Blossom St., Their 340, Boston, MA, 02114, USA.
- Department of Microbiology and Immunology, Harvard Medical School, 77 Ave. Louis Pasteur, Boston, MA, 02115, USA.
- Shriners Hospitals for Children-Boston®, 51 Blossom St., Boston, MA, 02114, USA.
| | - Shuang Xue
- Department of Medicine, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Lin Zhang
- Department of Medicine, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Jinghong Li
- Department of Medicine, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
| | - Willis X Li
- Department of Medicine, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA, 92093, USA
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21
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Albig C, Tikhonova E, Krause S, Maksimenko O, Regnard C, Becker PB. Factor cooperation for chromosome discrimination in Drosophila. Nucleic Acids Res 2019; 47:1706-1724. [PMID: 30541149 PMCID: PMC6393291 DOI: 10.1093/nar/gky1238] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/05/2018] [Accepted: 11/29/2018] [Indexed: 12/27/2022] Open
Abstract
Transcription regulators select their genomic binding sites from a large pool of similar, non-functional sequences. Although general principles that allow such discrimination are known, the complexity of DNA elements often precludes a prediction of functional sites. The process of dosage compensation in Drosophila allows exploring the rules underlying binding site selectivity. The male-specific-lethal (MSL) Dosage Compensation Complex (DCC) selectively binds to some 300 X chromosomal ‘High Affinity Sites’ (HAS) containing GA-rich ‘MSL recognition elements’ (MREs), but disregards thousands of other MRE sequences in the genome. The DNA-binding subunit MSL2 alone identifies a subset of MREs, but fails to recognize most MREs within HAS. The ‘Chromatin-linked adaptor for MSL proteins’ (CLAMP) also interacts with many MREs genome-wide and promotes DCC binding to HAS. Using genome-wide DNA-immunoprecipitation we describe extensive cooperativity between both factors, depending on the nature of the binding sites. These are explained by physical interaction between MSL2 and CLAMP. In vivo, both factors cooperate to compete with nucleosome formation at HAS. The male-specific MSL2 thus synergises with a ubiquitous GA-repeat binding protein for refined X/autosome discrimination.
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Affiliation(s)
- Christian Albig
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany.,Graduate School for Quantitative Biosciences (QBM), Ludwig-Maximilians-Universität Munich, 81377 Munich, Germany
| | - Evgeniya Tikhonova
- Group of Molecular Organization of Genome, Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Silke Krause
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany
| | - Oksana Maksimenko
- Group of Molecular Organization of Genome, Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Catherine Regnard
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany
| | - Peter B Becker
- Molecular Biology Division, Biomedical Center, Faculty of Medicine and Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität Munich, 82151 Martinsried, Germany
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22
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Oulhen N, Swartz SZ, Wang L, Wikramanayake A, Wessel GM. Distinct transcriptional regulation of Nanos2 in the germ line and soma by the Wnt and delta/notch pathways. Dev Biol 2019; 452:34-42. [PMID: 31075220 PMCID: PMC6848975 DOI: 10.1016/j.ydbio.2019.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/19/2019] [Accepted: 04/21/2019] [Indexed: 12/23/2022]
Abstract
Specification of the primordial germ cells (PGCs) is essential for sexually reproducing animals. Although the mechanisms of PGC specification are diverse between organisms, the RNA binding protein Nanos is consistently required in the germ line in all species tested. How Nanos is selectively expressed in the germ line, however, remains largely elusive. We report that in sea urchin embryos, the early expression of Nanos2 in the PGCs requires the maternal Wnt pathway. During gastrulation, however, Nanos2 expression expands into adjacent somatic mesodermal cells and this secondary Nanos expression instead requires Delta/Notch signaling through the forkhead family member FoxY. Each of these transcriptional regulators were tested by chromatin immunoprecipitation analysis and found to directly interact with a DNA locus upstream of Nanos2. Given the conserved importance of Nanos in germ line specification, and the derived character of the micromeres and small micromeres in the sea urchin, we propose that the ancestral mechanism of Nanos2 expression in echinoderms was by induction in mesodermal cells during gastrulation.
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Affiliation(s)
- Nathalie Oulhen
- Department of Molecular and Cell Biology and Biochemistry, Brown University, 185 Meeting Street, Providence, RI, 02912, USA
| | - S Zachary Swartz
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA, 02142, USA
| | - Lingyu Wang
- Department of Biology and Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | | | - Gary M Wessel
- Department of Molecular and Cell Biology and Biochemistry, Brown University, 185 Meeting Street, Providence, RI, 02912, USA.
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23
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Prayitno K, Schauer T, Regnard C, Becker PB. Progressive dosage compensation during Drosophila embryogenesis is reflected by gene arrangement. EMBO Rep 2019; 20:e48138. [PMID: 31286660 DOI: 10.15252/embr.201948138] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/07/2019] [Accepted: 06/18/2019] [Indexed: 12/24/2022] Open
Abstract
In Drosophila melanogaster males, X-chromosome monosomy is compensated by chromosome-wide transcription activation. We found that complete dosage compensation during embryogenesis takes surprisingly long and is incomplete even after 10 h of development. Although the activating dosage compensation complex (DCC) associates with the X-chromosome and MOF acetylates histone H4 early, many genes are not compensated. Acetylation levels on gene bodies continue to increase for several hours after gastrulation in parallel with progressive compensation. Constitutive genes are compensated earlier than developmental genes. Remarkably, later compensation correlates with longer distances to DCC binding sites. This time-space relationship suggests that DCC action on target genes requires maturation of the active chromosome compartment.
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Affiliation(s)
- Khairunnadiya Prayitno
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany.,Graduate School of Quantitative Biosciences Munich, Ludwig-Maximilians-University, Munich, Germany
| | - Tamás Schauer
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany.,Bioinformatics Unit, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany
| | - Catherine Regnard
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany
| | - Peter B Becker
- Molecular Biology Division, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany
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24
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Parey E, Crombach A. Evolution of the Drosophila melanogaster Chromatin Landscape and Its Associated Proteins. Genome Biol Evol 2019; 11:660-677. [PMID: 30689829 PMCID: PMC6411481 DOI: 10.1093/gbe/evz019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2019] [Indexed: 12/30/2022] Open
Abstract
In the nucleus of eukaryotic cells, genomic DNA associates with numerous protein complexes and RNAs, forming the chromatin landscape. Through a genome-wide study of chromatin-associated proteins in Drosophila cells, five major chromatin types were identified as a refinement of the traditional binary division into hetero- and euchromatin. These five types were given color names in reference to the Greek word chroma. They are defined by distinct but overlapping combinations of proteins and differ in biological and biochemical properties, including transcriptional activity, replication timing, and histone modifications. In this work, we assess the evolutionary relationships of chromatin-associated proteins and present an integrated view of the evolution and conservation of the fruit fly Drosophila melanogaster chromatin landscape. We combine homology prediction across a wide range of species with gene age inference methods to determine the origin of each chromatin-associated protein. This provides insight into the evolution of the different chromatin types. Our results indicate that for the euchromatic types, YELLOW and RED, young associated proteins are more specialized than old ones; and for genes found in either chromatin type, intron/exon structure is lineage-specific. Next, we provide evidence that a subset of GREEN-associated proteins is involved in a centromere drive in D. melanogaster. Our results on BLUE chromatin support the hypothesis that the emergence of Polycomb Group proteins is linked to eukaryotic multicellularity. In light of these results, we discuss how the regulatory complexification of chromatin links to the origins of eukaryotic multicellularity.
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Affiliation(s)
- Elise Parey
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Université Paris, France.,Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Université Paris, Paris, France
| | - Anton Crombach
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Université Paris, France.,Inria, Antenne Lyon La Doua, Villeurbanne, France.,Université de Lyon, INSA-Lyon, LIRIS, UMR 5205, Villeurbanne, France
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25
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Investigating the structural features of chromodomain proteins in the human genome and predictive impacts of their mutations in cancers. Int J Biol Macromol 2019; 131:1101-1116. [PMID: 30917913 DOI: 10.1016/j.ijbiomac.2019.03.162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/20/2019] [Accepted: 03/22/2019] [Indexed: 11/22/2022]
Abstract
Epigenetic readers are specific proteins which recognize histone marks and represents the underlying mechanism for chromatin regulation. Histone H3 lysine methylation is a potential epigenetic code for the chromatin organization and transcriptional control. Recognition of histone methylation is achieved by evolutionary conserved reader modules known as chromodomain, identified in several proteins, and is involved in transcriptional silencing and chromatin remodelling. Genetic perturbations within the structurally conserved chromodomain could potentially mistarget the reader protein and impair their regulatory pathways, ultimately leading to cellular chaos by setting the stage for tumor development and progression. Here, we report the structural conservations associated with diverse functions, prognostic significance and functional consequences of mutations within chromodomain of human proteins in distinct cancers. We have extensively analysed chromodomain containing human proteins in terms of their structural-functional ability to act as a molecular switch in the recognition of methyl-lysine recognition. We further investigated the combinatorial potential, target promiscuity and binding specificity associated with their underlying mechanisms. Indeed, the molecular mechanism of epigenetic silencing significantly underlies a newer cancer therapy approach. We hope that a critical understanding of chromodomains will pave the way for novel paths of research providing newer insights into the designing of effective anti-cancer therapies.
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26
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Dorafshan E, Kahn TG, Glotov A, Savitsky M, Walther M, Reuter G, Schwartz YB. Ash1 counteracts Polycomb repression independent of histone H3 lysine 36 methylation. EMBO Rep 2019; 20:embr.201846762. [PMID: 30833342 DOI: 10.15252/embr.201846762] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 01/31/2019] [Accepted: 02/05/2019] [Indexed: 12/11/2022] Open
Abstract
Polycomb repression is critical for metazoan development. Equally important but less studied is the Trithorax system, which safeguards Polycomb target genes from the repression in cells where they have to remain active. It was proposed that the Trithorax system acts via methylation of histone H3 at lysine 4 and lysine 36 (H3K36), thereby inhibiting histone methyltransferase activity of the Polycomb complexes. Here we test this hypothesis by asking whether the Trithorax group protein Ash1 requires H3K36 methylation to counteract Polycomb repression. We show that Ash1 is the only Drosophila H3K36-specific methyltransferase necessary to prevent excessive Polycomb repression of homeotic genes. Unexpectedly, our experiments reveal no correlation between the extent of H3K36 methylation and the resistance to Polycomb repression. Furthermore, we find that complete substitution of the zygotic histone H3 with a variant in which lysine 36 is replaced by arginine does not cause excessive repression of homeotic genes. Our results suggest that the model, where the Trithorax group proteins methylate histone H3 to inhibit the histone methyltransferase activity of the Polycomb complexes, needs revision.
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Affiliation(s)
| | - Tatyana G Kahn
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | | | | | - Matthias Walther
- Institute of Developmental Genetics, Martin-Luther University of Halle-Wittenberg, Halle, Germany.,Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Gunter Reuter
- Institute of Developmental Genetics, Martin-Luther University of Halle-Wittenberg, Halle, Germany
| | - Yuri B Schwartz
- Department of Molecular Biology, Umeå University, Umeå, Sweden
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Oulhen N, Foster S, Wray G, Wessel G. Identifying gene expression from single cells to single genes. Methods Cell Biol 2019; 151:127-158. [PMID: 30948004 DOI: 10.1016/bs.mcb.2018.11.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Gene regulatory networks reveal how transcription factors contribute to a dynamic cascade of cellular information processing. Recent advances in technologies have enhanced the toolkit for testing GRN mechanisms and connections. Here we emphasize three approaches that we have found important for interrogating transcriptional mechanisms in echinoderms: single cell mRNA sequencing (drop-seq), nascent RNA detection and identification, and chromatin immunoprecipitation (ChIP). We present these applications in order since it is a logical experimental protocol. With preliminary information from bulk mRNA transcriptome analysis and differential gene expression studies (DE-seq), one may need to test in what specific cells important genes may be expressed and to use single cell sequencing to define such links. Nascent RNA analysis with the Click-iT chemistry allows the investigator to deduce when the RNA was transcribed, not just identify its presence, and ChIP allows the investigator to study direct interactions of putative transcriptional regulators with the gene promoter of interest. This flow of thinking, and the technologies to support it, is presented here for echinoderms. While many of the procedures are general and applicable to many organisms and cell types, we emphasize unique aspects of the protocols for consideration in using echinoderm embryos, larvae, and adult tissues.
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Affiliation(s)
- Nathalie Oulhen
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Stephany Foster
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Greg Wray
- Department of Biology, Duke University, Durham, NC, United States
| | - Gary Wessel
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, United States.
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Lee H, Oliver B. Non-canonical Drosophila X chromosome dosage compensation and repressive topologically associated domains. Epigenetics Chromatin 2018; 11:62. [PMID: 30355339 PMCID: PMC6199721 DOI: 10.1186/s13072-018-0232-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/15/2018] [Indexed: 12/20/2022] Open
Abstract
Background In animals with XY sex chromosomes, X-linked genes from a single X chromosome in males are imbalanced relative to autosomal genes. To minimize the impact of genic imbalance in male Drosophila, there is a dosage compensation complex (MSL) that equilibrates X-linked gene expression with the autosomes. There are other potential contributions to dosage compensation. Hemizygous autosomal genes located in repressive chromatin domains are often derepressed. If this homolog-dependent repression occurs on the X, which has no pairing partner, then derepression could contribute to male dosage compensation. Results We asked whether different chromatin states or topological associations correlate with X chromosome dosage compensation, especially in regions with little MSL occupancy. Our analyses demonstrated that male X chromosome genes that are located in repressive chromatin states are depleted of MSL occupancy; however, they show dosage compensation. The genes in these repressive regions were also less sensitive to knockdown of MSL components. Conclusions Our results suggest that this non-canonical dosage compensation is due to the same transacting derepression that occurs on autosomes. This mechanism would facilitate immediate compensation during the evolution of sex chromosomes from autosomes. This mechanism is similar to that of C. elegans, where enhanced recruitment of X chromosomes to the nuclear lamina dampens X chromosome expression as part of the dosage compensation response in XX individuals. Electronic supplementary material The online version of this article (10.1186/s13072-018-0232-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hangnoh Lee
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, USA. .,Section on Cell Cycle Regulation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
| | - Brian Oliver
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, USA
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Chromatin That Guides Dosage Compensation Is Modulated by the siRNA Pathway in Drosophila melanogaster. Genetics 2018; 209:1085-1097. [PMID: 29921620 PMCID: PMC6063223 DOI: 10.1534/genetics.118.301173] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/15/2018] [Indexed: 12/03/2022] Open
Abstract
A family of X-linked repetitive elements enhances dosage compensation of nearby genes in male flies. Here, Deshpande and Meller show that chromatin around these repeats is modified in a siRNA-dependent manner. Proteins that interact with the siRNA effector... Many heterogametic organisms adjust sex chromosome expression to accommodate differences in gene dosage. This requires selective recruitment of regulatory factors to the modulated chromosome. How these factors are localized to a chromosome with requisite accuracy is poorly understood. Drosophila melanogaster males increase expression from their single X chromosome. Identification of this chromosome involves cooperation between different classes of X-identity elements. The chromatin entry sites (CES) recruit a chromatin-modifying complex that spreads into nearby genes and increases expression. In addition, a family of satellite repeats that is enriched on the X chromosome, the 1.688X repeats, promotes recruitment of the complex to nearby genes. The 1.688X repeats and CES are dissimilar, and appear to operate through different mechanisms. Interestingly, the siRNA pathway and siRNA from a 1.688X repeat also promote X recognition. We postulate that siRNA-dependent modification of 1.688X chromatin contributes to recognition of nearby genes. In accord with this, we found enrichment of the siRNA effector Argonaute2 (Ago2) at some 1.688X repeats. Mutations in several proteins that physically interact with Ago2, including the histone methyltransferase Su(var)3-9, enhance the lethality of males with defective X recognition. Su(var)3-9 deposits H3K9me2 on some 1.688X repeats, and this mark is disrupted upon ectopic expression of 1.688X siRNA. Furthermore, integration of 1.688X DNA on an autosome induces local H3K9me2 deposition, but enhances expression of nearby genes in a siRNA-dependent manner. Our findings are consistent with a model in which siRNA-directed modification of 1.688X chromatin contributes to recognition of the male X chromosome for dosage compensation.
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Wang T, Holt MV, Young NL. The histone H4 proteoform dynamics in response to SUV4-20 inhibition reveals single molecule mechanisms of inhibitor resistance. Epigenetics Chromatin 2018; 11:29. [PMID: 29880017 PMCID: PMC5992683 DOI: 10.1186/s13072-018-0198-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 05/27/2018] [Indexed: 12/25/2022] Open
Abstract
Background The dynamics of histone post-translational modifications (PTMs) are sparsely described, especially in their true physiological context of proteoforms (single histone molecules harboring combinations of PTMs). Methods Here we time-resolve the response of cells to SUV4-20 methyltransferase inhibition and unbiasedly quantitate the dynamic response of histone H4 PTMs and proteoforms. Results Contrary to the prevailing dogma, cells exhibit an immediate-early response with changes to histone proteoforms. Cells also recover to basal-like conditions upon removal of epigenetic inhibitors rapidly. Inhibition of SUV4-20 results in decreased H4{K20me2}; however, no effects on H4{K20me3} are observed, implying that another enzyme mediates H4K20me3. Most surprisingly, SUV4-20 inhibition results in an increase in histone H4 acetylation attributable to proteoforms containing K20me2. This led us to hypothesize that hyperacetylated proteoforms protect K20me2 from demethylation as an evolved compensatory mechanism. This concept is supported by subsequent results that pretreatment with an HDACi substantially diminishes the effects of SUV4-20 inhibition in prone cells and is further confirmed by HATi-facilitating SUV4-20 inhibition to decrease discrete H4{K20me2} in resistant cells. Conclusions The chromatin response of cells to sudden perturbations is significantly faster, nuanced and complex than previously described. The persistent nature of chromatin regulation may be achieved by a network of dynamic equilibria with compensatory mechanisms that operate at the proteoform level. Electronic supplementary material The online version of this article (10.1186/s13072-018-0198-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tao Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Matthew V Holt
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Nicolas L Young
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA. .,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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31
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Samata M, Akhtar A. Dosage Compensation of the X Chromosome: A Complex Epigenetic Assignment Involving Chromatin Regulators and Long Noncoding RNAs. Annu Rev Biochem 2018; 87:323-350. [PMID: 29668306 DOI: 10.1146/annurev-biochem-062917-011816] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
X chromosome regulation represents a prime example of an epigenetic phenomenon where coordinated regulation of a whole chromosome is required. In flies, this is achieved by transcriptional upregulation of X chromosomal genes in males to equalize the gene dosage differences in females. Chromatin-bound proteins and long noncoding RNAs (lncRNAs) constituting a ribonucleoprotein complex known as the male-specific lethal (MSL) complex or the dosage compensation complex mediate this process. MSL complex members decorate the male X chromosome, and their absence leads to male lethality. The male X chromosome is also enriched with histone H4 lysine 16 acetylation (H4K16ac), indicating that the chromatin compaction status of the X chromosome also plays an important role in transcriptional activation. How the X chromosome is specifically targeted and how dosage compensation is mechanistically achieved are central questions for the field. Here, we review recent advances, which reveal a complex interplay among lncRNAs, the chromatin landscape, transcription, and chromosome conformation that fine-tune X chromosome gene expression.
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Affiliation(s)
- Maria Samata
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany; .,Faculty of Biology, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Asifa Akhtar
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg im Breisgau, Germany;
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Schmähling S, Meiler A, Lee Y, Mohammed A, Finkl K, Tauscher K, Israel L, Wirth M, Philippou-Massier J, Blum H, Habermann B, Imhof A, Song JJ, Müller J. Regulation and function of H3K36 di-methylation by the trithorax-group protein complex AMC. Development 2018. [PMID: 29540501 PMCID: PMC5963871 DOI: 10.1242/dev.163808] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Drosophila Ash1 protein is a trithorax-group (trxG) regulator that antagonizes Polycomb repression at HOX genes. Ash1 di-methylates lysine 36 in histone H3 (H3K36me2) but how this activity is controlled and at which genes it functions is not well understood. We show that Ash1 protein purified from Drosophila exists in a complex with MRG15 and Caf1 that we named AMC. In Drosophila and human AMC, MRG15 binds a conserved FxLP motif near the Ash1 SET domain and stimulates H3K36 di-methylation on nucleosomes. Drosophila MRG15-null and ash1 catalytic mutants show remarkably specific trxG phenotypes: stochastic loss of HOX gene expression and homeotic transformations in adults. In mutants lacking AMC, H3K36me2 bulk levels appear undiminished but H3K36me2 is reduced in the chromatin of HOX and other AMC-regulated genes. AMC therefore appears to act on top of the H3K36me2/me3 landscape generated by the major H3K36 methyltransferases NSD and Set2. Our analyses suggest that H3K36 di-methylation at HOX genes is the crucial physiological function of AMC and the mechanism by which the complex antagonizes Polycomb repression at these genes. Highlighted Article: The trithorax group protein Ash1 and its regulator MRG15 form a multiprotein complex that maintains expression of HOX and other target genes by methylating histone H3 in their chromatin.
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Affiliation(s)
- Sigrun Schmähling
- Max-Planck Institute of Biochemistry, Laboratory of Chromatin Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Arno Meiler
- Max-Planck Institute of Biochemistry, Computational Biology, Am Klopferspitz 18 82152 Martinsried, Germany
| | - Yoonjung Lee
- Korea Advanced Institute of Science and Technology (KAIST), Department of Biological Sciences, Daejeon 34141, Korea
| | - Arif Mohammed
- Max-Planck Institute of Biochemistry, Laboratory of Chromatin Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Katja Finkl
- Max-Planck Institute of Biochemistry, Laboratory of Chromatin Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Katharina Tauscher
- Max-Planck Institute of Biochemistry, Laboratory of Chromatin Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Lars Israel
- Zentrallabor für Proteinanalytik, BioMedical Center, Ludwig-Maximilians-University Munich, Großhadernerstr. 9, 82152 Martinsried, Germany
| | - Marc Wirth
- Zentrallabor für Proteinanalytik, BioMedical Center, Ludwig-Maximilians-University Munich, Großhadernerstr. 9, 82152 Martinsried, Germany
| | - Julia Philippou-Massier
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Helmut Blum
- Laboratory for Functional Genome Analysis (LAFUGA), Gene Center, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Bianca Habermann
- Max-Planck Institute of Biochemistry, Computational Biology, Am Klopferspitz 18 82152 Martinsried, Germany
| | - Axel Imhof
- Zentrallabor für Proteinanalytik, BioMedical Center, Ludwig-Maximilians-University Munich, Großhadernerstr. 9, 82152 Martinsried, Germany
| | - Ji-Joon Song
- Korea Advanced Institute of Science and Technology (KAIST), Department of Biological Sciences, Daejeon 34141, Korea
| | - Jürg Müller
- Max-Planck Institute of Biochemistry, Laboratory of Chromatin Biology, Am Klopferspitz 18, 82152 Martinsried, Germany
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Li J, Duns G, Westers H, Sijmons R, van den Berg A, Kok K. SETD2: an epigenetic modifier with tumor suppressor functionality. Oncotarget 2018; 7:50719-50734. [PMID: 27191891 PMCID: PMC5226616 DOI: 10.18632/oncotarget.9368] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/05/2016] [Indexed: 11/25/2022] Open
Abstract
In the past decade important progress has been made in our understanding of the epigenetic regulatory machinery. It has become clear that genetic aberrations in multiple epigenetic modifier proteins are associated with various types of cancer. Moreover, targeting the epigenome has emerged as a novel tool to treat cancer patients. Recently, the first drugs have been reported that specifically target SETD2-negative tumors. In this review we discuss the studies on the associated protein, Set domain containing 2 (SETD2), a histone modifier for which mutations have only recently been associated with cancer development. Our review starts with the structural characteristics of SETD2 and extends to its corresponding function by combining studies on SETD2 function in yeast, Drosophila, Caenorhabditis elegans, mice, and humans. SETD2 is now generally known as the single human gene responsible for trimethylation of lysine 36 of Histone H3 (H3K36). H3K36me3 readers that recruit protein complexes to carry out specific processes, including transcription elongation, RNA processing, and DNA repair, determine the impact of this histone modification. Finally, we describe the prevalence of SETD2-inactivating mutations in cancer, with the highest frequency in clear cell Renal Cell Cancer, and explore how SETD2-inactivation might contribute to tumor development.
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Affiliation(s)
- Jun Li
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Gerben Duns
- Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, Canada
| | - Helga Westers
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Rolf Sijmons
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Anke van den Berg
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Klaas Kok
- Department of Genetics, University of Groningen, University Medical Center Groningen, The Netherlands
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Drosophila Dosage Compensation Loci Associate with a Boundary-Forming Insulator Complex. Mol Cell Biol 2017; 37:MCB.00253-17. [PMID: 28784719 DOI: 10.1128/mcb.00253-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/10/2017] [Indexed: 12/18/2022] Open
Abstract
Chromatin entry sites (CES) are 100- to 1,500-bp elements that recruit male-specific lethal (MSL) complexes to the X chromosome to upregulate expression of X-linked genes in male flies. CES contain one or more ∼20-bp GA-rich sequences called MSL recognition elements (MREs) that are critical for dosage compensation. Recent studies indicate that CES also correspond to boundaries of X-chromosomal topologically associated domains (TADs). Here, we show that an ∼1,000-kDa complex called the late boundary complex (LBC), which is required for the functioning of the Bithorax complex boundary Fab-7, interacts specifically with a special class of CES that contain multiple MREs. Mutations in the MRE sequences of three of these CES that disrupt function in vivo abrogate interactions with the LBC. Moreover, reducing the levels of two LBC components compromises MSL recruitment. Finally, we show that several of the CES that are physically linked to each other in vivo are LBC interactors.
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36
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Structure and mechanism of plant histone mark readers. SCIENCE CHINA-LIFE SCIENCES 2017; 61:170-177. [PMID: 29019143 DOI: 10.1007/s11427-017-9163-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 08/11/2017] [Indexed: 10/18/2022]
Abstract
In eukaryotes, epigenetic-based mechanisms are involved in almost all the important biological processes. Amongst different epigenetic regulation pathways, the dynamic covalent modifications on histones are the most extensively investigated and characterized types. The covalent modifications on histone can be "read" by specific protein domains and then subsequently trigger downstream signaling events. Plants generally possess epigenetic regulation systems similar to animals and fungi, but also exhibit some plant-specific features. Similar to animals and fungi, plants require distinct protein domains to specifically "read" modified histones in both modification-specific and sequence-specific manners. In this review, we will focus on recent progress of the structural studies on the recognition of the epigenetic marks on histones by plant reader proteins, and further summarize the general and exceptional features of plant histone mark readers.
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Schauer T, Ghavi‐Helm Y, Sexton T, Albig C, Regnard C, Cavalli G, Furlong EEM, Becker PB. Chromosome topology guides the Drosophila Dosage Compensation Complex for target gene activation. EMBO Rep 2017; 18:1854-1868. [PMID: 28794204 PMCID: PMC5623837 DOI: 10.15252/embr.201744292] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/30/2017] [Accepted: 07/04/2017] [Indexed: 11/09/2022] Open
Abstract
X chromosome dosage compensation in Drosophila requires chromosome-wide coordination of gene activation. The male-specific lethal dosage compensation complex (DCC) identifies and binds to X-chromosomal high-affinity sites (HAS) from which it boosts transcription. A sub-class of HAS, PionX sites, represent first contacts on the X. Here, we explored the chromosomal interactions of representative PionX sites by high-resolution 4C and determined the global chromosome conformation by Hi-C in sex-sorted embryos. Male and female X chromosomes display similar nuclear architecture, concordant with clustered, constitutively active genes. PionX sites, like HAS, are evenly distributed in the active compartment and engage in short- and long-range interactions beyond compartment boundaries. Long-range, inter-domain interactions between DCC binding sites are stronger in males, suggesting that the complex refines chromatin organization. By de novo induction of DCC in female cells, we monitored the extent of activation surrounding PionX sites. This revealed a remarkable range of DCC action not only in linear proximity, but also at megabase distance if close in space, suggesting that DCC profits from pre-existing chromosome folding to activate genes.
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Affiliation(s)
- Tamás Schauer
- Molecular Biology DivisionBiomedical Center and Center for Integrated Protein Science Ludwig‐Maximilians‐UniversityMunichGermany
| | - Yad Ghavi‐Helm
- European Molecular Biology LaboratoryGenome Biology UnitHeidelbergGermany
| | - Tom Sexton
- Institute of Genetics and Molecular and Cellular BiologyIllkirchFrance
| | - Christian Albig
- Molecular Biology DivisionBiomedical Center and Center for Integrated Protein Science Ludwig‐Maximilians‐UniversityMunichGermany
| | - Catherine Regnard
- Molecular Biology DivisionBiomedical Center and Center for Integrated Protein Science Ludwig‐Maximilians‐UniversityMunichGermany
| | - Giacomo Cavalli
- Institute of Human GeneticsCNRSMontpellierFrance
- University of MontpellierMontpellierFrance
| | - Eileen EM Furlong
- European Molecular Biology LaboratoryGenome Biology UnitHeidelbergGermany
| | - Peter B Becker
- Molecular Biology DivisionBiomedical Center and Center for Integrated Protein Science Ludwig‐Maximilians‐UniversityMunichGermany
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Bennett RL, Swaroop A, Troche C, Licht JD. The Role of Nuclear Receptor-Binding SET Domain Family Histone Lysine Methyltransferases in Cancer. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a026708. [PMID: 28193767 DOI: 10.1101/cshperspect.a026708] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The nuclear receptor-binding SET Domain (NSD) family of histone H3 lysine 36 methyltransferases is comprised of NSD1, NSD2 (MMSET/WHSC1), and NSD3 (WHSC1L1). These enzymes recognize and catalyze methylation of histone lysine marks to regulate chromatin integrity and gene expression. The growing number of reports demonstrating that alterations or translocations of these genes fundamentally affect cell growth and differentiation leading to developmental defects illustrates the importance of this family. In addition, overexpression, gain of function somatic mutations, and translocations of NSDs are associated with human cancer and can trigger cellular transformation in model systems. Here we review the functions of NSD family members and the accumulating evidence that these proteins play key roles in tumorigenesis. Because epigenetic therapy is an important emerging anticancer strategy, understanding the function of NSD family members may lead to the development of novel therapies.
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Affiliation(s)
- Richard L Bennett
- Departments of Medicine, Biochemistry and Molecular Biology and University of Florida Health Cancer Center, The University of Florida, Gainesville, Florida 32610
| | - Alok Swaroop
- Departments of Medicine, Biochemistry and Molecular Biology and University of Florida Health Cancer Center, The University of Florida, Gainesville, Florida 32610
| | - Catalina Troche
- Departments of Medicine, Biochemistry and Molecular Biology and University of Florida Health Cancer Center, The University of Florida, Gainesville, Florida 32610
| | - Jonathan D Licht
- Departments of Medicine, Biochemistry and Molecular Biology and University of Florida Health Cancer Center, The University of Florida, Gainesville, Florida 32610
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Dosage Compensation in Drosophila-a Model for the Coordinate Regulation of Transcription. Genetics 2017; 204:435-450. [PMID: 27729494 DOI: 10.1534/genetics.115.185108] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 07/25/2016] [Indexed: 12/20/2022] Open
Abstract
The sex chromosomes have special significance in the history of genetics. The chromosomal basis of inheritance was firmly established when Calvin Bridges demonstrated that exceptions to Mendel's laws of segregation were accompanied at the cytological level by exceptional sex chromosome segregation. The morphological differences between X and Y exploited in Bridges' experiments arose as a consequence of the evolution of the sex chromosomes. Originally a homologous chromosome pair, the degeneration of the Y chromosome has been accompanied by a requirement for increased expression of the single X chromosome in males. Drosophila has been a model for the study of this dosage compensation and has brought key strengths, including classical genetics, the exceptional cytology of polytene chromosomes, and more recently, comprehensive genomics. The impact of these studies goes beyond sex chromosome regulation, providing valuable insights into mechanisms for the establishment and maintenance of chromatin domains, and for the coordinate regulation of transcription.
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Abstract
Dosage compensation in some animals involves up-regulation of genes on the male's X chromosome. A study in the fruit fly Drosophila melanogaster shows that satellite DNA, and corresponding small non-coding RNA, helps the dosage compensation machinery preferentially find X sequences.
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Affiliation(s)
- Patrick M Ferree
- W.M. Keck Science Department, Claremont McKenna, Pitzer and Scripps Colleges, 925 N. Mills Avenue, Claremont, CA 91711, USA.
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Ectopic protein interactions within BRD4-chromatin complexes drive oncogenic megadomain formation in NUT midline carcinoma. Proc Natl Acad Sci U S A 2017; 114:E4184-E4192. [PMID: 28484033 DOI: 10.1073/pnas.1702086114] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
To investigate the mechanism that drives dramatic mistargeting of active chromatin in NUT midline carcinoma (NMC), we have identified protein interactions unique to the BRD4-NUT fusion oncoprotein compared with wild-type BRD4. Using cross-linking, affinity purification, and mass spectrometry, we identified the EP300 acetyltransferase as uniquely associated with BRD4 through the NUT fusion in both NMC and non-NMC cell types. We also discovered ZNF532 associated with BRD4-NUT in NMC patient cells but not detectable in 293T cells. EP300 and ZNF532 are both implicated in feed-forward regulatory loops leading to propagation of the oncogenic chromatin complex in BRD4-NUT patient cells. Adding key functional significance to our biochemical findings, we independently discovered a ZNF532-NUT translocation fusion in a newly diagnosed NMC patient. ChIP sequencing of the major players NUT, ZNF532, BRD4, EP300, and H3K27ac revealed the formation of ZNF532-NUT-associated hyperacetylated megadomains, distinctly localized but otherwise analogous to those found in BRD4-NUT patient cells. Our results support a model in which NMC is dependent on ectopic NUT-mediated interactions between EP300 and components of BRD4 regulatory complexes, leading to a cascade of misregulation.
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Joshi SS, Meller VH. Satellite Repeats Identify X Chromatin for Dosage Compensation in Drosophila melanogaster Males. Curr Biol 2017; 27:1393-1402.e2. [PMID: 28457869 DOI: 10.1016/j.cub.2017.03.078] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 02/28/2017] [Accepted: 03/29/2017] [Indexed: 11/19/2022]
Abstract
A common feature of sex chromosomes is coordinated regulation of X-linked genes in one sex. Drosophila melanogaster males have one X chromosome, whereas females have two. The resulting imbalance in gene dosage is corrected by increased expression from the single X chromosome of males, a process known as dosage compensation. In flies, compensation involves recruitment of the male-specific lethal (MSL) complex to X-linked genes and modification of chromatin to increase expression. The extraordinary selectivity of the MSL complex for the X chromosome has never been explained. We previously demonstrated that the small interfering RNA (siRNA) pathway and siRNA from a family of X-linked satellite repeats (1.688X repeats) promote X recognition. Now, we test the ability of 1.688X DNA to attract compensation to genes nearby and report that autosomal integration of 1.688X repeats increases MSL recruitment and gene expression in surrounding regions. Placement of 1.688X repeats opposite a lethal autosomal deletion achieves partial rescue of males, demonstrating functional compensation of autosomal chromatin. Females block formation of the MSL complex and are not rescued. The 1.688X repeats are therefore cis-acting elements that guide dosage compensation. Furthermore, 1.688X siRNA enhances rescue of males with a lethal deletion but only when repeat DNA is present on the intact homolog. We propose that the siRNA pathway promotes X recognition by enhancing the ability of 1.688X DNA to attract compensation in cis. The dense and near-exclusive distribution of 1.688X sequences along the X chromosome suggests that they play a primary role in determining X identity during dosage compensation.
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Affiliation(s)
- Sonal S Joshi
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48020, USA
| | - Victoria H Meller
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI 48020, USA.
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43
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Meers MP, Henriques T, Lavender CA, McKay DJ, Strahl BD, Duronio RJ, Adelman K, Matera AG. Histone gene replacement reveals a post-transcriptional role for H3K36 in maintaining metazoan transcriptome fidelity. eLife 2017; 6. [PMID: 28346137 PMCID: PMC5404926 DOI: 10.7554/elife.23249] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 03/23/2017] [Indexed: 12/17/2022] Open
Abstract
Histone H3 lysine 36 methylation (H3K36me) is thought to participate in a host of co-transcriptional regulatory events. To study the function of this residue independent from the enzymes that modify it, we used a ‘histone replacement’ system in Drosophila to generate a non-modifiable H3K36 lysine-to-arginine (H3K36R) mutant. We observed global dysregulation of mRNA levels in H3K36R animals that correlates with the incidence of H3K36me3. Similar to previous studies, we found that mutation of H3K36 also resulted in H4 hyperacetylation. However, neither cryptic transcription initiation, nor alternative pre-mRNA splicing, contributed to the observed changes in expression, in contrast with previously reported roles for H3K36me. Interestingly, knockdown of the RNA surveillance nuclease, Xrn1, and members of the CCR4-Not deadenylase complex, restored mRNA levels for a class of downregulated, H3K36me3-rich genes. We propose a post-transcriptional role for modification of replication-dependent H3K36 in the control of metazoan gene expression. DOI:http://dx.doi.org/10.7554/eLife.23249.001 In a single human cell there is enough DNA to stretch over a meter if laid end to end. To fit this DNA inside the cell – which is less than 20 micrometers in diameter – the DNA is tightly wrapped around millions of proteins known as histones, which look like “beads” along a “string” of DNA. These histones can prevent other proteins from binding to DNA and activating specific genes. Therefore, cells use enzymes to chemically modify histones to allow particular stretches of DNA to be unwrapped at specific times. Proteins are made up of building blocks called amino acids. A specific amino acid on histones known as H3K36 is modified in certain sections of DNA that suggest it affects the activities of many genes. However, the precise role of this amino acid remains unclear. Previous studies have tried to investigate this by removing the enzymes that modify it, but these enzymes can also modify many other proteins, making it difficult to know what exactly causes the changes in gene activity. Fruit flies are often used in experiments as models of how genetic processes work in humans and other animals. Like us, fruit flies also package their DNA using histones. To investigate the role of H3K36, Meers et al. generated a mutant fruit fly that has a version of the amino acid that cannot be chemically modified by the normal enzymes. Unexpectedly, the experiments suggest that some changes in gene activity that have been previously reported to be caused by modifying H3K36 might actually be due to other factors. Meers et al. found that H3K36 modifications may instead “mark” certain genes to be more active than they otherwise would be. These findings provide a starting point for understanding exactly how H3K36 regulates gene activity. The next challenge is to refine our understanding of how H3K36 modification affects genes in cancer and other diseases, which may aid the development of new therapies to treat these conditions. DOI:http://dx.doi.org/10.7554/eLife.23249.002
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Affiliation(s)
- Michael P Meers
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Telmo Henriques
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Science, Durham, United States
| | - Christopher A Lavender
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Science, Durham, United States
| | - Daniel J McKay
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Brian D Strahl
- Department of Biochemistry and Biophysics, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Karen Adelman
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Science, Durham, United States
| | - A Gregory Matera
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, United States.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, United States
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Structural studies on MRG701 chromodomain reveal a novel dimerization interface of MRG proteins in green plants. Protein Cell 2016; 7:792-803. [PMID: 27638467 PMCID: PMC5084153 DOI: 10.1007/s13238-016-0310-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 07/26/2016] [Indexed: 12/03/2022] Open
Abstract
MRG proteins are conserved during evolution in fungi, flies, mammals and plants, and they can exhibit diversified functions. The animal MRGs were found to form various complexes to activate gene expression. Plant MRG1/2 and MRG702 were reported to be involved in the regulation of flowering time via binding to H3K36me3-marked flowering genes. Herein, we determined the crystal structure of MRG701 chromodomain (MRG701CD). MRG701CD forms a novel dimerization fold both in crystal and in solution. Moreover, we found that the dimerization of MRG chromodomains is conserved in green plants. Our findings may provide new insights into the mechanism of MRGs in regulation of gene expression in green plants.
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45
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Jeltsch A, Jurkowska RZ. Allosteric control of mammalian DNA methyltransferases - a new regulatory paradigm. Nucleic Acids Res 2016; 44:8556-8575. [PMID: 27521372 PMCID: PMC5062992 DOI: 10.1093/nar/gkw723] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/08/2016] [Indexed: 12/23/2022] Open
Abstract
In mammals, DNA methylation is introduced by the DNMT1, DNMT3A and DNMT3B methyltransferases, which are all large multi-domain proteins containing a catalytic C-terminal domain and an N-terminal part with regulatory functions. Recently, two novel regulatory principles of DNMTs were uncovered. It was shown that their catalytic activity is under allosteric control of N-terminal domains with autoinhibitory function, the RFT and CXXC domains in DNMT1 and the ADD domain in DNMT3. Moreover, targeting and activity of DNMTs were found to be regulated in a concerted manner by interactors and posttranslational modifications (PTMs). In this review, we describe the structures and domain composition of the DNMT1 and DNMT3 enzymes, their DNA binding, catalytic mechanism, multimerization and the processes controlling their stability in cells with a focus on their regulation and chromatin targeting by PTMs, interactors and chromatin modifications. We propose that the allosteric regulation of DNMTs by autoinhibitory domains acts as a general switch for the modulation of the function of DNMTs, providing numerous possibilities for interacting proteins, nucleic acids or PTMs to regulate DNMT activity and targeting. The combined regulation of DNMT targeting and catalytic activity contributes to the precise spatiotemporal control of DNMT function and genome methylation in cells.
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Affiliation(s)
- Albert Jeltsch
- Institute of Biochemistry, Pfaffenwaldring 55, Faculty of Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Renata Z Jurkowska
- BioMed X Innovation Center, Im Neuenheimer Feld 583, D-69120 Heidelberg, Germany
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Kuzu G, Kaye EG, Chery J, Siggers T, Yang L, Dobson JR, Boor S, Bliss J, Liu W, Jogl G, Rohs R, Singh ND, Bulyk ML, Tolstorukov MY, Larschan E. Expansion of GA Dinucleotide Repeats Increases the Density of CLAMP Binding Sites on the X-Chromosome to Promote Drosophila Dosage Compensation. PLoS Genet 2016; 12:e1006120. [PMID: 27414415 PMCID: PMC4945028 DOI: 10.1371/journal.pgen.1006120] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 05/23/2016] [Indexed: 12/15/2022] Open
Abstract
Dosage compensation is an essential process that equalizes transcript levels of X-linked genes between sexes by forming a domain of coordinated gene expression. Throughout the evolution of Diptera, many different X-chromosomes acquired the ability to be dosage compensated. Once each newly evolved X-chromosome is targeted for dosage compensation in XY males, its active genes are upregulated two-fold to equalize gene expression with XX females. In Drosophila melanogaster, the CLAMP zinc finger protein links the dosage compensation complex to the X-chromosome. However, the mechanism for X-chromosome identification has remained unknown. Here, we combine biochemical, genomic and evolutionary approaches to reveal that expansion of GA-dinucleotide repeats likely accumulated on the X-chromosome over evolutionary time to increase the density of CLAMP binding sites, thereby driving the evolution of dosage compensation. Overall, we present new insight into how subtle changes in genomic architecture, such as expansions of a simple sequence repeat, promote the evolution of coordinated gene expression.
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Affiliation(s)
- Guray Kuzu
- Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, Rhode Island, United States of America
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Emily G. Kaye
- Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, Rhode Island, United States of America
| | - Jessica Chery
- Department of Cell Biology, Massachusetts General Hospital Cancer Center, Boston, Massachusetts, United States of America
| | - Trevor Siggers
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Lin Yang
- Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Jason R. Dobson
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Sonia Boor
- Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, Rhode Island, United States of America
| | - Jacob Bliss
- Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, Rhode Island, United States of America
| | - Wei Liu
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Gerwald Jogl
- Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, Rhode Island, United States of America
| | - Remo Rohs
- Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Nadia D. Singh
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Martha L. Bulyk
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Pathology, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Michael Y. Tolstorukov
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- * E-mail: (MYT); (EL)
| | - Erica Larschan
- Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, Providence, Rhode Island, United States of America
- * E-mail: (MYT); (EL)
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47
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Structure and function of histone methylation-binding proteins in plants. Biochem J 2016; 473:1663-80. [DOI: 10.1042/bcj20160123] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/29/2016] [Indexed: 12/28/2022]
Abstract
Post-translational modifications of histones play important roles in modulating many essential biological processes in both animals and plants. These covalent modifications, including methylation, acetylation, phosphorylation, ubiquitination, SUMOylation and so on, are laid out and erased by histone-modifying enzymes and read out by effector proteins. Recent studies have revealed that a number of developmental processes in plants are under the control of histone post-translational modifications, such as floral transition, seed germination, organogenesis and morphogenesis. Therefore, it is critical to identify those protein domains, which could specifically recognize these post-translational modifications to modulate chromatin structure and regulate gene expression. In the present review, we discuss the recent progress in understanding the structure and function of the histone methylation readers in plants, by focusing on Arabidopsis thaliana proteins.
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48
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Jurkowska RZ, Jeltsch A. Enzymology of Mammalian DNA Methyltransferases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 945:87-122. [PMID: 27826836 DOI: 10.1007/978-3-319-43624-1_5] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
DNA methylation is currently one of the hottest topics in basic and biomedical research. Despite tremendous progress in understanding the structures and biochemical properties of the mammalian DNA nucleotide methyltransferases (DNMTs), principles of their regulation in cells have only begun to be uncovered. In mammals, DNA methylation is introduced by the DNMT1, DNMT3A, and DNMT3B enzymes, which are all large multi-domain proteins. These enzymes contain a catalytic C-terminal domain with a characteristic cytosine-C5 methyltransferase fold and an N-terminal part with different domains that interacts with other proteins and chromatin and is involved in targeting and regulation of the DNMTs. The subnuclear localization of the DNMT enzymes plays an important role in their biological function: DNMT1 is localized to replicating DNA via interaction with PCNA and UHRF1. DNMT3 enzymes bind to heterochromatin via protein multimerization and are targeted to chromatin by their ADD and PWWP domains. Recently, a novel regulatory mechanism has been discovered in DNMTs, as latest structural and functional data demonstrated that the catalytic activities of all three enzymes are under tight allosteric control of their N-terminal domains having autoinhibitory functions. This mechanism provides numerous possibilities for the precise regulation of the methyltransferases via controlling the binding and release of autoinhibitory domains by protein factors, noncoding RNAs, or by posttranslational modifications of the DNMTs. In this chapter, we summarize key enzymatic properties of DNMTs, including their specificity and processivity, and afterward we focus on the regulation of their activity and targeting via allosteric processes, protein interactors, and posttranslational modifications.
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Affiliation(s)
- Renata Z Jurkowska
- BioMed X Innovation Center, Im Neuenheimer Feld 583, Heidelberg, D-69120, Germany.
| | - Albert Jeltsch
- Institute of Biochemistry, Faculty of Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, D-70569, Germany.
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Heterochromatin remodeling by CDK12 contributes to learning in Drosophila. Proc Natl Acad Sci U S A 2015; 112:13988-93. [PMID: 26508632 DOI: 10.1073/pnas.1502943112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dynamic regulation of chromatin structure is required to modulate the transcription of genes in eukaryotes. However, the factors that contribute to the plasticity of heterochromatin structure are elusive. Here, we report that cyclin-dependent kinase 12 (CDK12), a transcription elongation-associated RNA polymerase II (RNAPII) kinase, antagonizes heterochromatin enrichment in Drosophila chromosomes. Notably, loss of CDK12 induces the ectopic accumulation of heterochromatin protein 1 (HP1) on euchromatic arms, with a prominent enrichment on the X chromosome. Furthermore, ChIP and sequencing analysis reveals that the heterochromatin enrichment on the X chromosome mainly occurs within long genes involved in neuronal functions. Consequently, heterochromatin enrichment reduces the transcription of neuronal genes in the adult brain and results in a defect in Drosophila courtship learning. Taken together, these results define a previously unidentified role of CDK12 in controlling the epigenetic transition between euchromatin and heterochromatin and suggest a chromatin regulatory mechanism in neuronal behaviors.
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50
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Modulation of Heterochromatin by Male Specific Lethal Proteins and roX RNA in Drosophila melanogaster Males. PLoS One 2015; 10:e0140259. [PMID: 26468879 PMCID: PMC4607463 DOI: 10.1371/journal.pone.0140259] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/27/2015] [Indexed: 01/04/2023] Open
Abstract
The ribonucleoprotein Male Specific Lethal (MSL) complex is required for X chromosome dosage compensation in Drosophila melanogaster males. Beginning at 3 h of development the MSL complex binds transcribed X-linked genes and modifies chromatin. A subset of MSL complex proteins, including MSL1 and MSL3, is also necessary for full expression of autosomal heterochromatic genes in males, but not females. Loss of the non-coding roX RNAs, essential components of the MSL complex, lowers the expression of heterochromatic genes and suppresses position effect variegation (PEV) only in males, revealing a sex-limited disruption of heterochromatin. To explore the molecular basis of this observation we examined additional proteins that participate in compensation and found that MLE, but not Jil-1 kinase, contributes to heterochromatic gene expression. To determine if identical regions of roX RNA are required for dosage compensation and heterochromatic silencing, we tested a panel of roX1 transgenes and deletions and find that the X chromosome and heterochromatin functions are separable by some mutations. Chromatin immunoprecipitation of staged embryos revealed widespread autosomal binding of MSL3 before and after localization of the MSL complex to the X chromosome at 3 h AEL. Autosomal MSL3 binding was dependent on MSL1, supporting the idea that a subset of MSL proteins associates with chromatin throughout the genome during early development. The broad localization of these proteins early in embryogenesis supports the idea of direct action at autosomal sites. We postulate that this may contribute to the sex-specific differences in heterochromatin that we, and others, have noted.
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