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Sad K, Jones CY, Fawwal DV, Hill EJ, Skinner K, Lustenberger S, Lee RS, Elayavalli SR, Farhi J, Lemon LD, Fasken MB, Hong AL, Sloan SA, Corbett AH, Spangle JM. Histone H3 E50K mutation confers oncogenic activity and supports an EMT phenotype. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.11.561775. [PMID: 37873162 PMCID: PMC10592736 DOI: 10.1101/2023.10.11.561775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Sequencing of human patient tumors has identified recurrent missense mutations in genes encoding core histones. We report that mutations that convert histone H3 amino acid 50 from a glutamate to a lysine (H3E50K) support an oncogenic phenotype in human cells. Expression of H3E50K is sufficient to transform human cells as evidenced by a dramatic increase in cell migration and invasion, and a statistically significant increase in proliferation and clonogenicity. H3E50K also increases the invasive phenotype in the context of co-occurring BRAF mutations, which are present in patient tumors characterized by H3E50K. H3E50 lies on the globular domain surface in a region that contacts H4 within the nucleosome. We find that H3E50K perturbs proximal H3 post-translational modifications globally and dysregulates gene expression, activating the epithelial to mesenchymal transition. Functional studies using S. cerevisiae reveal that, while yeast cells that express H3E50K as the sole copy of histone H3 show sensitivity to cellular stressors, including caffeine, H3E50K cells display some genetic interactions that are distinct from the characterized H3K36M oncohistone yeast model. Taken together, these data suggest that additional histone H3 mutations have the potential to be oncogenic drivers and function through distinct mechanisms that dysregulate gene expression.
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2
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Jayakrishnan M, Havlová M, Veverka V, Regnard C, Becker P. Genomic context-dependent histone H3K36 methylation by three Drosophila methyltransferases and implications for dedicated chromatin readers. Nucleic Acids Res 2024; 52:7627-7649. [PMID: 38813825 PMCID: PMC11260483 DOI: 10.1093/nar/gkae449] [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: 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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Anyetei-Anum CS, Leatham-Jensen MP, Fox GC, Smith BR, Krajewski K, Strahl BD, Dowen JM, Matera AG, Duronio RJ, McKay DJ. Dual roles of histone H3 lysine-4 in antagonizing Polycomb group function and promoting target gene expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.25.600669. [PMID: 38979215 PMCID: PMC11230394 DOI: 10.1101/2024.06.25.600669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Tight control over cell identity gene expression is necessary for proper adult form and function. The opposing activities of Polycomb and trithorax complexes determine the ON/OFF state of targets like the Hox genes. Trithorax encodes a methyltransferase specific to histone H3 lysine-4 (H3K4). However, there is no direct evidence that H3K4 regulates Polycomb group target genes in vivo . Here, we demonstrate two key roles for replication-dependent histone H3.2K4 in target control. We find that H3.2K4 antagonizes Polycomb group catalytic activity and that it is required for proper target gene activation. We conclude that H3.2K4 directly regulates expression of Polycomb targets.
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4
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Crain AT, Butler MB, Hill CA, Huynh M, McGinty RK, Duronio RJ. Drosophila melanogaster Set8 and L(3)mbt function in gene expression independently of histone H4 lysine 20 methylation. Genes Dev 2024; 38:455-472. [PMID: 38866557 PMCID: PMC11216177 DOI: 10.1101/gad.351698.124] [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: 03/12/2024] [Accepted: 05/29/2024] [Indexed: 06/14/2024]
Abstract
Monomethylation of lysine 20 of histone H4 (H4K20me1) is catalyzed by Set8 and thought to play important roles in many aspects of genome function that are mediated by H4K20me binding proteins. We interrogated this model in a developing animal by comparing in parallel the transcriptomes of Set8 null , H4 K20R/A , and l(3)mbt mutant Drosophila melanogaster We found that the gene expression profiles of H4 K20A and H4 K20R larvae are markedly different than Set8 null larvae despite similar reductions in H4K20me1. Set8 null mutant cells have a severely disrupted transcriptome and fail to proliferate in vivo, but these phenotypes are not recapitulated by mutation of H4 K20 , indicating that the developmental defects of Set8 null animals are largely due to H4K20me1-independent effects on gene expression. Furthermore, the H4K20me1 binding protein L(3)mbt is recruited to the transcription start sites of most genes independently of H4K20me even though genes bound by L(3)mbt have high levels of H4K20me1. Moreover, both Set8 and L(3)mbt bind to purified H4K20R nucleosomes in vitro. We conclude that gene expression changes in Set8 null and H4 K20 mutants cannot be explained by loss of H4K20me1 or L(3)mbt binding to chromatin and therefore that H4K20me1 does not play a large role in gene expression.
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Affiliation(s)
- Aaron T Crain
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599 USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 USA
| | - Megan B Butler
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599 USA
| | - Christina A Hill
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 USA
| | - Mai Huynh
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599 USA
- Division of Chemical Biology and Medicinal Chemistry, Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599 USA
| | - Robert K McGinty
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599 USA
- Division of Chemical Biology and Medicinal Chemistry, Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599 USA
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599 USA
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina 27599 USA;
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 USA
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599 USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599 USA
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599 USA
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5
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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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6
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Crain AT, Nevil M, Leatham-Jensen MP, Reeves KB, Matera AG, McKay DJ, Duronio RJ. Redesigning the Drosophila histone gene cluster: An improved genetic platform for spatiotemporal manipulation of histone function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.591202. [PMID: 38712307 PMCID: PMC11071459 DOI: 10.1101/2024.04.25.591202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Mutating replication-dependent (RD) histone genes is an important tool for understanding chromatin-based epigenetic regulation. Deploying this tool in metazoan models is particularly challenging because RD histones in these organisms are typically encoded by many genes, often located at multiple loci. Such RD histone gene arrangements make the ability to generate homogenous histone mutant genotypes by site-specific gene editing quite difficult. Drosophila melanogaster provides a solution to this problem because the RD histone genes are organized into a single large tandem array that can be deleted and replaced with transgenes containing mutant histone genes. In the last ∼15 years several different RD histone gene replacement platforms have been developed using this simple strategy. However, each platform contains weaknesses that preclude full use of the powerful developmental genetic capabilities available to Drosophila researchers. Here we describe the development of a newly engineered platform that rectifies many of these weaknesses. We used CRISPR to precisely delete the RD histone gene array ( HisC ), replacing it with a multifunctional cassette that permits site-specific insertion of either one or two synthetic gene arrays using selectable markers. We designed this cassette with the ability to selectively delete each of the integrated gene arrays in specific tissues using site-specific recombinases. We also present a method for rapidly synthesizing histone gene arrays of any genotype using Golden Gate cloning technologies. These improvements facilitate generation of histone mutant cells in various tissues at different stages of Drosophila development and provide an opportunity to apply forward genetic strategies to interrogate chromatin structure and gene regulation.
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7
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Brown JC, McMichael BD, Vandadi V, Mukherjee A, Salzler HR, Matera AG. Lysine-36 of Drosophila histone H3.3 supports adult longevity. G3 (BETHESDA, MD.) 2024; 14:jkae030. [PMID: 38366796 PMCID: PMC10989886 DOI: 10.1093/g3journal/jkae030] [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: 01/16/2024] [Revised: 01/16/2023] [Accepted: 02/04/2024] [Indexed: 02/18/2024]
Abstract
Aging is a multifactorial process that disturbs homeostasis, increases disease susceptibility, and ultimately results in death. Although the definitive set of molecular mechanisms responsible for aging remain to be discovered, epigenetic change over time is proving to be a promising piece of the puzzle. Several post-translational histone modifications have been linked to the maintenance of longevity. Here, we focus on lysine-36 of the replication-independent histone protein, H3.3 (H3.3K36). To interrogate the role of this residue in Drosophila developmental gene regulation, we generated a lysine-to-arginine mutant that blocks the activity of its cognate-modifying enzymes. We found that an H3.3BK36R mutation causes a significant reduction in adult lifespan, accompanied by dysregulation of the genomic and transcriptomic architecture. Transgenic co-expression of wild-type H3.3B completely rescues the longevity defect. Because H3.3 is known to accumulate in nondividing tissues, we carried out transcriptome profiling of young vs aged adult fly heads. The data show that loss of H3.3K36 results in age-dependent misexpression of NF-κB and other innate immune target genes, as well as defects in silencing of heterochromatin. We propose H3.3K36 maintains the postmitotic epigenomic landscape, supporting longevity by regulating both pericentric and telomeric retrotransposons and by suppressing aberrant immune signaling.
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Affiliation(s)
- John C Brown
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Benjamin D McMichael
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Vasudha Vandadi
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Aadit Mukherjee
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Harmony R Salzler
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
| | - A Gregory Matera
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
- RNA Discovery Center, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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8
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Crain AT, Butler MB, Hill CA, Huynh M, McGinty RK, Duronio RJ. Drosophila melanogaster Set8 and L(3)mbt function in gene expression independently of histone H4 lysine 20 methylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584710. [PMID: 38559189 PMCID: PMC10980064 DOI: 10.1101/2024.03.12.584710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Mono-methylation of Lysine 20 of histone H4 (H4K20me1) is catalyzed by Set8 and thought to play important roles in many aspects of genome function that are mediated by H4K20me-binding proteins. We interrogated this model in a developing animal by comparing in parallel the transcriptomes of Set8 null , H4 K20R/A , and l(3)mbt mutant Drosophila melanogaster . We found that the gene expression profiles of H4 K20A and H4 K20R larvae are markedly different than Set8 null larvae despite similar reductions in H4K20me1. Set8 null mutant cells have a severely disrupted transcriptome and fail to proliferate in vivo , but these phenotypes are not recapitulated by mutation of H4 K20 indicating that the developmental defects of Set8 null animals are largely due to H4K20me1-independent effects on gene expression. Further, the H4K20me1 binding protein L(3)mbt is recruited to the transcription start sites of most genes independently of H4K20me even though genes bound by L(3)mbt have high levels of H4K20me1. Moreover, both Set8 and L(3)mbt bind to purified H4K20R nucleosomes in vitro. We conclude that gene expression changes in Set8 null and H4 K20 mutants cannot be explained by loss of H4K20me1 or L(3)mbt binding to chromatin, and therefore that H4K20me1 does not play a large role in gene expression.
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9
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Niederhuber MJ, Leatham-Jensen M, McKay DJ. The SWI/SNF nucleosome remodeler constrains enhancer activity during Drosophila wing development. Genetics 2024; 226:iyad196. [PMID: 37949841 PMCID: PMC10847718 DOI: 10.1093/genetics/iyad196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/05/2023] [Accepted: 10/30/2023] [Indexed: 11/12/2023] Open
Abstract
Chromatin remodeling is central to the dynamic changes in gene expression that drive cell fate determination. During development, the sets of enhancers that are accessible for use change globally as cells transition between stages. While transcription factors and nucleosome remodelers are known to work together to control enhancer accessibility, it is unclear how the short stretches of DNA that they individually unmask yield the kilobase-sized accessible regions characteristic of active enhancers. Here, we performed a genetic screen to investigate the role of nucleosome remodelers in control of dynamic enhancer activity. We find that the Drosophila Switch/Sucrose Non-Fermenting complex, BAP, is required for repression of a temporally dynamic enhancer, brdisc. Contrary to expectations, we find that the BAP-specific subunit Osa is dispensable for mediating changes in chromatin accessibility between the early and late stages of wing development. Instead, we find that Osa is required to constrain the levels of brdisc activity when the enhancer is normally active. Genome-wide profiling reveals that Osa directly binds brdisc as well as thousands of other developmentally dynamic regulatory sites, including multiple genes encoding components and targets of the Notch signaling pathway. Transgenic reporter analyses demonstrate that Osa is required for activation and for constraint of different sets of target enhancers in the same cells. Moreover, Osa loss results in hyperactivation of the Notch ligand Delta and development of ectopic sensory structures patterned by Notch signaling early in development. Together, these findings indicate that proper constraint of enhancer activity is necessary for regulation of dose-dependent developmental events.
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Affiliation(s)
- Matthew J Niederhuber
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Mary Leatham-Jensen
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Daniel J McKay
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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10
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Brown JC, McMichael BD, Vandadi V, Mukherjee A, Salzler HR, Matera AG. Lysine-36 of Drosophila histone H3.3 supports adult longevity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.28.559962. [PMID: 38196611 PMCID: PMC10775331 DOI: 10.1101/2023.09.28.559962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Aging is a multifactorial process that disturbs homeostasis, increases disease susceptibility, and ultimately results in death. Although the definitive set of molecular mechanisms responsible for aging remain to be discovered, epigenetic change over time is proving to be a promising piece of the puzzle. Several posttranslational histone modifications (PTMs) have been linked to the maintenance of longevity. Here, we focus on lysine-36 of the replication-independent histone protein, H3.3 (H3.3K36). To interrogate the role of this residue in Drosophila developmental gene regulation, we generated a lysine to arginine mutant that blocks the activity of its cognate modifying enzymes. We found that an H3.3BK36R mutation causes a significant reduction in adult lifespan, accompanied by dysregulation of the genomic and transcriptomic architecture. Transgenic co-expression of wild-type H3.3B completely rescues the longevity defect. Because H3.3 is known to accumulate in non-dividing tissues, we carried out transcriptome profiling of young vs aged adult fly heads. The data show that loss of H3.3K36 results in age-dependent misexpression of NF-κB and other innate immune target genes, as well as defects in silencing of heterochromatin. We propose H3.3K36 maintains the postmitotic epigenomic landscape, supporting longevity by regulating both pericentric and telomeric retrotransposons and by suppressing aberrant immune signaling.
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Affiliation(s)
- John C. Brown
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
| | - Benjamin D. McMichael
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, USA
- Department of Biology, 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
| | - Aadit Mukherjee
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
| | - Harmony R. Salzler
- 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 Biology, University of North Carolina, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- RNA Discovery Center, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
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11
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McPherson JME, Grossmann LC, Salzler HR, Armstrong RL, Kwon E, Matera AG, McKay DJ, Duronio RJ. Reduced histone gene copy number disrupts Drosophila Polycomb function. Genetics 2023; 224:iyad106. [PMID: 37279945 PMCID: PMC10411577 DOI: 10.1093/genetics/iyad106] [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: 03/27/2023] [Revised: 05/19/2023] [Accepted: 05/30/2023] [Indexed: 06/08/2023] Open
Abstract
The chromatin of animal cells contains two types of histones: canonical histones that are expressed during S phase of the cell cycle to package the newly replicated genome, and variant histones with specialized functions that are expressed throughout the cell cycle and in non-proliferating cells. Determining whether and how canonical and variant histones cooperate to regulate genome function is integral to understanding how chromatin-based processes affect normal and pathological development. Here, we demonstrate that variant histone H3.3 is essential for Drosophila development only when canonical histone gene copy number is reduced, suggesting that coordination between canonical H3.2 and variant H3.3 expression is necessary to provide sufficient H3 protein for normal genome function. To identify genes that depend upon, or are involved in, this coordinate regulation we screened for heterozygous chromosome 3 deficiencies that impair development of flies bearing reduced H3.2 and H3.3 gene copy number. We identified two regions of chromosome 3 that conferred this phenotype, one of which contains the Polycomb gene, which is necessary for establishing domains of facultative chromatin that repress master regulator genes during development. We further found that reduction in Polycomb dosage decreases viability of animals with no H3.3 gene copies. Moreover, heterozygous Polycomb mutations result in de-repression of the Polycomb target gene Ubx and cause ectopic sex combs when either canonical or variant H3 gene copy number is reduced. We conclude that Polycomb-mediated facultative heterochromatin function is compromised when canonical and variant H3 gene copy number falls below a critical threshold.
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Affiliation(s)
- Jeanne-Marie E McPherson
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Lucy C Grossmann
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Harmony R Salzler
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Robin L Armstrong
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Esther Kwon
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - A Gregory Matera
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Daniel J McKay
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Robert J Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
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12
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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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McPherson JME, Grossmann LC, Armstrong RL, Kwon E, Salzler HR, Matera AG, McKay DJ, Duronio RJ. Reduced histone gene copy number disrupts Drosophila Polycomb function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534544. [PMID: 37034607 PMCID: PMC10081267 DOI: 10.1101/2023.03.28.534544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The chromatin of animal cells contains two types of histones: canonical histones that are expressed during S phase of the cell cycle to package the newly replicated genome, and variant histones with specialized functions that are expressed throughout the cell cycle and in non-proliferating cells. Determining whether and how canonical and variant histones cooperate to regulate genome function is integral to understanding how chromatin-based processes affect normal and pathological development. Here, we demonstrate that variant histone H3.3 is essential for Drosophila development only when canonical histone gene copy number is reduced, suggesting that coordination between canonical H3.2 and variant H3.3 expression is necessary to provide sufficient H3 protein for normal genome function. To identify genes that depend upon, or are involved in, this coordinate regulation we screened for heterozygous chromosome 3 deficiencies that impair development of flies bearing reduced H3.2 and H3.3 gene copy number. We identified two regions of chromosome 3 that conferred this phenotype, one of which contains the Polycomb gene, which is necessary for establishing domains of facultative chromatin that repress master regulator genes during development. We further found that reduction in Polycomb dosage decreases viability of animals with no H3.3 gene copies. Moreover, heterozygous Polycomb mutations result in de-repression of the Polycomb target gene Ubx and cause ectopic sex combs when either canonical or variant H3 gene copy number is also reduced. We conclude that Polycomb-mediated facultative heterochromatin function is compromised when canonical and variant H3 gene copy number falls below a critical threshold.
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Affiliation(s)
- Jeanne-Marie E. McPherson
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599 USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Lucy C. Grossmann
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Robin L. Armstrong
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599 USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Esther Kwon
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Harmony R. Salzler
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - A. Gregory Matera
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599 USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Daniel J. McKay
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599 USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Robert J. Duronio
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC, 27599 USA
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA
- Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
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