This SuperSeries is composed of the SubSeries listed below.
Placing the HIRA histone chaperone complex in the chromatin landscape.
Specimen part
View SamplesThe HIRA chaperone complex, comprised of HIRA, UBN1 and CABIN1, collaborates with histone-binding protein ASF1a to incorporate histone variant H3.3 into chromatin in a DNA replication-independent manner. To better understand its function and mechanism, we integrated HIRA, UBN1, ASF1a and histone H3.3 ChIP-seq and gene expression analyses. Most HIRA-binding sites co-localize with UBN1, ASF1a and H3.3 at active promoters and active and weak/poised enhancers. At promoters, binding of HIRA/UBN1/ASF1a correlates with the level of gene expression. HIRA is required for deposition of histone H3.3 at its binding sites. There are marked differences in nucleosome and co-regulator composition at different classes of HIRA-bound regulatory site. Underscoring this, we report novel physical interactions between the HIRA complex and transcription factors, a chromatin insulator and an ATP-dependent chromatin-remodelling complex. Our results map the distribution of the HIRA chaperone across the chromatin landscape and point to different interacting partners at functionally distinct regulatory sites.
Placing the HIRA histone chaperone complex in the chromatin landscape.
Specimen part
View SamplesThe mammalian HIRA/UBN1/ASF1a complex is a histone chaperone complex that is conserved from yeast (Saccharomyces cerevisiae) to humans. This complex preferentially deposits the histone variant H3.3 into chromatin in a DNA replication-independent manner and is implicated in diverse chromatin regu- latory events from gene activation to heterochromatinization. In yeast, the orthologous complex consists of three Hir proteins (Hir1p, Hir2p, and Hir3p), Hpc2p, and Asf1p. Yeast Hir3p has weak homology to CABIN1, a fourth member of the human complex, suggesting that Hir3p and CABIN1 may be orthologs. Here we show that HIRA and CABIN1 interact at ectopic and endogenous levels of expression in cells, and we isolate the quaternary HIRA/UBN1/CABIN1/ASF1a (HUCA) complex, assembled from recombinant proteins. Mutational analyses support the view that HIRA acts as a scaffold to bring together UBN1, ASF1a, and CABIN1 into a quaternary complex. We show that, like HIRA, UBN1, and ASF1a, CABIN1 is involved in heterochromatinization of the genome of senescent human cells. Moreover, in proliferating cells, HIRA and CABIN1 regulate overlapping sets of genes, and these genes are enriched in the histone variant H3.3. In sum, these data demonstrate that CABIN1 is a functional member of the human HUCA complex and so is the likely ortholog of yeast Hir3p.
Human CABIN1 is a functional member of the human HIRA/UBN1/ASF1a histone H3.3 chaperone complex.
Specimen part
View SamplesIMR90 cells were passaged until replicative senescence and compared with proliferating cells. Overall design: We used RNA-Seq to detail the global programme of gene expression in human IMR90 replicative induced senescence
Mapping H4K20me3 onto the chromatin landscape of senescent cells indicates a function in control of cell senescence and tumor suppression through preservation of genetic and epigenetic stability.
No sample metadata fields
View SamplesIMR90 cells were infected with pLNC-RAS:ER (from Jesus Gil lab) with retroviral gene transfer. Infected cells were drug selected G418. The cells were induced either with ethanol as control or with 100nM final conc 4-hydroxytamoxifen (sigma H7904) for ectopic expression of protein Overall design: We used RNA-Seq to detail the global programme of gene expression in human IMR90 oncogene induced senescence
Mapping H4K20me3 onto the chromatin landscape of senescent cells indicates a function in control of cell senescence and tumor suppression through preservation of genetic and epigenetic stability.
No sample metadata fields
View SamplesIntroduction: There is increasing evidence that consumption of cocoa products have a beneficial effect on cardio-metabolic health, but the underlying mechanisms remain unclear. Cocoa contains a complex mixture of flavan-3-ols. Epicatechin, a major monomeric flavan-3-ol, is considered to contribute to the cardio-protective effects of cocoa. We investigated effects of pure epicatechin supplementation on whole genome gene expression profiles of circulating immune cells. Methods: In a randomized, double blind, placebo-controlled cross-over trial, 37 (pre)hypertensive (40-80y) subjects received two 4-week interventions; epicatechin (100mg/day) or placebo with a wash-out period of 4-week between both interventions. Whole genome gene expression profiles of peripheral blood mononuclear cells were determined before and after both interventions. Results: After epicatechin supplementation 1180 genes were significantly regulated, of which 234 were also significantly regulated compared to placebo. Epicatechin supplementation up-regulated gene sets involved in transcription/translation and tubulin folding and down-regulated gene sets involved in inflammation. Only a few genes within these regulated gene sets were actually significantly changed upon epicatechin supplementation. Upstream regulators that were shown to be inhibited were classified as cytokine or inflammatory type molecules. Conclusion: Pure epicatechin supplementation modestly reduced gene expression related to inflammation signalling routes in circulating immune cells. These routes are known to play a role in cardiovascular health
Pure flavonoid epicatechin and whole genome gene expression profiles in circulating immune cells in adults with elevated blood pressure: A randomised double-blind, placebo-controlled, crossover trial.
Treatment, Subject
View SamplesMicroRNA-125b is abundant in hearts while its function is not well understood. We used microarray to investigate the global changes of transcriptome for functional evaluation.
Cardiac-specific microRNA-125b deficiency induces perinatal death and cardiac hypertrophy.
Specimen part
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