共查询到20条相似文献,搜索用时 31 毫秒
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Aging is accompanied by alterations in epigenetic marks that control chromatin states, including histone acetylation and methylation. Enzymes that reversibly affect histone marks associated with active chromatin have recently been found to regulate aging in Caenorhabditis elegans. However, relatively little is known about the importance for aging of histone marks associated with repressed chromatin. Here, we use a targeted RNAi screen in C. elegans to identify four histone demethylases that significantly regulate worm lifespan, UTX‐1, RBR‐2, LSD‐1, and T26A5.5. Interestingly, UTX‐1 belongs to a conserved family of histone demethylases specific for lysine 27 of histone H3 (H3K27me3), a mark associated with repressed chromatin. Both utx‐1 knockdown and heterozygous mutation of utx‐1 extend lifespan and increase the global levels of the H3K27me3 mark in worms. The H3K27me3 mark significantly drops in somatic cells during the normal aging process. UTX‐1 regulates lifespan independently of the presence of the germline, but in a manner that depends on the insulin‐FoxO signaling pathway. These findings identify the H3K27me3 histone demethylase UTX‐1 as a novel regulator of worm lifespan in somatic cells. 相似文献
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The HP1α–CAF1–SetDB1‐containing complex provides H3K9me1 for Suv39‐mediated K9me3 in pericentric heterochromatin 下载免费PDF全文
Alejandra Loyola Tiziana Bonaldi Danièle Roche Jean Pierre Quivy Axel Imhof Yoshihiro Nakatani Sharon Y R Dent Geneviève Almouzni 《EMBO reports》2009,10(7):769-775
Trimethylation of lysine 9 in histone H3 (H3K9me3) enrichment is a characteristic of pericentric heterochromatin. The hypothesis of a stepwise mechanism to establish and maintain this mark during DNA replication suggests that newly synthesized histone H3 goes through an intermediate methylation state to become a substrate for the histone methyltransferase Suppressor of variegation 39 (Suv39H1/H2). How this intermediate methylation state is achieved and how it is targeted to the correct place at the right time is not yet known. Here, we show that the histone H3K9 methyltransferase SetDB1 associates with the specific heterochromatin protein 1α (HP1α)–chromatin assembly factor 1 (CAF1) chaperone complex. This complex monomethylates K9 on non‐nucleosomal histone H3. Therefore, the heterochromatic HP1α–CAF1–SetDB1 complex probably provides H3K9me1 for subsequent trimethylation by Suv39H1/H2 in pericentric regions. The connection of CAF1 with DNA replication, HP1α with heterochromatin formation and SetDB1 for H3K9me1 suggests a highly coordinated mechanism to ensure the propagation of H3K9me3 in pericentric heterochromatin during DNA replication. 相似文献
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The H3K27 methyltransferase CLF inhibits lateral root(LR) formation through depositing the repressive H3K27me3 mark to the chromatin of PIN1, a key polar auxin transporter gene. Here, we show that the H3K27me3 demethylase REF6 promotes lateral root primordium initiation and LR emergence. REF6 directly binds to the chromatin of PIN1/3/7. Dysfunction in REF6 results in increased levels of H3K27me3 on PIN1/3/7 and suppressed expression of PIN genes. Genetic analysis of the clf ref6 double mutant revealed an antagonistic action between CLF and REF6, in terms of LR formation.Our findings indicate that H3K27 methylation and demethylation activities are likely coordinated to ensure proper LR organogenesis. 相似文献
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A model for transmission of the H3K27me3 epigenetic mark 总被引:1,自引:0,他引:1
Hansen KH Bracken AP Pasini D Dietrich N Gehani SS Monrad A Rappsilber J Lerdrup M Helin K 《Nature cell biology》2008,10(11):1291-1300
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Vandamme J Lettier G Sidoli S Di Schiavi E Nørregaard Jensen O Salcini AE 《PLoS genetics》2012,8(5):e1002647
Epigenetic modifications influence gene expression and provide a unique mechanism for fine-tuning cellular differentiation and development in multicellular organisms. Here we report on the biological functions of UTX-1, the Caenorhabditis elegans homologue of mammalian UTX, a histone demethylase specific for H3K27me2/3. We demonstrate that utx-1 is an essential gene that is required for correct embryonic and postembryonic development. Consistent with its homology to UTX, UTX-1 regulates global levels of H3K27me2/3 in C. elegans. Surprisingly, we found that the catalytic activity is not required for the developmental function of this protein. Biochemical analysis identified UTX-1 as a component of a complex that includes SET-16(MLL), and genetic analysis indicates that the defects associated with loss of UTX-1 are likely mediated by compromised SET-16/UTX-1 complex activity. Taken together, these results demonstrate that UTX-1 is required for many aspects of nematode development; but, unexpectedly, this function is independent of its enzymatic activity. 相似文献
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Jarid1b targets genes regulating development and is involved in neural differentiation 总被引:1,自引:0,他引:1
Schmitz SU Albert M Malatesta M Morey L Johansen JV Bak M Tommerup N Abarrategui I Helin K 《The EMBO journal》2011,30(22):4586-4600
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The X-linked mental retardation gene SMCX/JARID1C defines a family of histone H3 lysine 4 demethylases 总被引:15,自引:0,他引:15
Iwase S Lan F Bayliss P de la Torre-Ubieta L Huarte M Qi HH Whetstine JR Bonni A Roberts TM Shi Y 《Cell》2007,128(6):1077-1088
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Beatrice Rondinelli Hélène Schwerer Elena Antonini Marco Gaviraghi Alessio Lupi Michela Frenquelli Davide Cittaro Simona Segalla Jean-Marc Lemaitre Giovanni Tonon 《Nucleic acids research》2015,43(5):2560-2574
DNA replication is a tightly regulated process that initiates from multiple replication origins and leads to the faithful transmission of the genetic material. For proper DNA replication, the chromatin surrounding origins needs to be remodeled. However, remarkably little is known on which epigenetic changes are required to allow the firing of replication origins. Here, we show that the histone demethylase KDM5C/JARID1C is required for proper DNA replication at early origins. JARID1C dictates the assembly of the pre-initiation complex, driving the binding to chromatin of the pre-initiation proteins CDC45 and PCNA, through the demethylation of the histone mark H3K4me3. Fork activation and histone H4 acetylation, additional early events involved in DNA replication, are not affected by JARID1C downregulation. All together, these data point to a prominent role for JARID1C in a specific phase of DNA replication in mammalian cells, through its demethylase activity on H3K4me3. 相似文献
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Jin C Li J Green CD Yu X Tang X Han D Xian B Wang D Huang X Cao X Yan Z Hou L Liu J Shukeir N Khaitovich P Chen CD Zhang H Jenuwein T Han JD 《Cell metabolism》2011,14(2):161-172
Epigenetic modifications are thought to be important for gene expression changes during development and aging. However, besides the Sir2 histone deacetylase in somatic tissues and H3K4 trimethylation in germlines, there is scant evidence implicating epigenetic regulations in aging. The insulin/IGF-1 signaling (IIS) pathway is a major life span regulatory pathway. Here, we show that progressive increases in gene expression and loss of H3K27me3 on IIS components are due, at least in part, to increased activity of the H3K27 demethylase UTX-1 during aging. RNAi of the utx-1 gene extended the mean life span of C. elegans by ~30%, dependent on DAF-16 activity and not additive in daf-2 mutants. The loss of utx-1 increased H3K27me3 on the Igf1r/daf-2 gene and decreased IIS activity, leading to a more "naive" epigenetic state. Like stem cell reprogramming, our results suggest that reestablishment of epigenetic marks lost during aging might help "reset" the developmental age of animal cells. 相似文献