Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA128575 | ENA |
REPOSITORIES: ENA
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Project description:Nucleosomal incorporation of specialized histone variants is an important mechanism to generate different functional chromatin states. Here we report the identification and characterization of two novel primate-specific histone H3 variants, H3.X and H3.Y. Their mRNAs are found in certain human cell lines, in addition to several normal and malignant human tissues. In keeping with their primate-specificity, H3.X and H3.Y are detected in different brain regions. Transgenic H3.X and H3.Y proteins are stably incorporated into chromatin in a similar fashion to the known H3 variants. Importantly, we demonstrate biochemically and by mass spectrometry that endogenous posttranslationally modified H3.Y protein exists in vivo, and that stress-stimuli, such as starvation and cellular density, increase the abundance of H3.Y-expressing cells. Global transcriptome analysis revealed that knock-down of H3.Y affects cell growth and leads to changes in the expression of many genes involved in cell cycle control. Thus, H3.Y is a novel histone variant involved in the regulation of cellular responses to outside stimuli. Total RNA samples from human U2OS cells. Transcript levels after luciferase, H3.X and/or H3.Y RNAi was analyzed.
2010-09-17 | E-GEOD-22415 | biostudies-arrayexpress
Project description:Nucleosomal incorporation of specialized histone variants is an important mechanism to generate different functional chromatin states. Here we report the identification and characterization of two novel primate-specific histone H3 variants, H3.X and H3.Y. Their mRNAs are found in certain human cell lines, in addition to several normal and malignant human tissues. In keeping with their primate-specificity, H3.X and H3.Y are detected in different brain regions. Transgenic H3.X and H3.Y proteins are stably incorporated into chromatin in a similar fashion to the known H3 variants. Importantly, we demonstrate biochemically and by mass spectrometry that endogenous posttranslationally modified H3.Y protein exists in vivo, and that stress-stimuli, such as starvation and cellular density, increase the abundance of H3.Y-expressing cells. Global transcriptome analysis revealed that knock-down of H3.Y affects cell growth and leads to changes in the expression of many genes involved in cell cycle control. Thus, H3.Y is a novel histone variant involved in the regulation of cellular responses to outside stimuli.
2010-09-17 | GSE22415 | GEO
Project description:Mass spectrometry (MS) is now well recognized as a powerful technique to identify and quantify post-translational modifications (PTMs), overcoming many of the limitations of antibody-based methods. Histones, which play a central role in all DNA-templated processes, are regulated by a wealth of dynamic modifications, particularly on their numerous lysine residues. Reliable identification of histone PTMs remains challenging and still requires manual data curation. In this study, we focused on the Lys27-Arg40 stretch of histone H3 and considered four sequence variants, an increasing number of lysine PTMs, and chemical artefacts coming from the specific protocol of histone sample processing, which resulted in many peptides with the same atomic composition. Our analysis revealed the value of low-mass b1 and cyclic immonium fragment ions for validation of the identification of the distinct peptide forms. We examined how MS/MS spectra are transformed by several common software tools during the conversion of raw files into peak lists, and highlighted how some parameters may erase the informative low-mass fragments. We established the fragmentation profiles and retention times for forty H3 K27-R40 variant×PTM combinations, including the mouse-specific variants H3mm7 and H3mm13, and targeted their detection in histone samples extracted from mouse testis and brain via a scheduled parallel reaction monitoring (PRM) analysis. These two mouse-specific variants were reported to be highly abundant at the transcript level in these tissues and may seem to be identified at the protein level by data-dependent MS acquisition. However, we only detected very low levels of the unmodified form of H3mm7 and found no trace of H3mm13 by PRM. Our work contributes to reliably deciphering the histone code shaped by distinct sequence variants and numerous combinations of PTMs.
2025-04-22 | PXD057347 | Pride
Project description:Histone chaperones prevent promiscuous histone interactions before chromatin assembly. They guarantee faithful deposition of canonical histones and functionally specialized histone variants into chromatin in a spatial- and temporally-restricted manner. Here, we identify the binding partners of the primate-specific and H3.3-related histone variant H3.Y using several quantitative mass spectrometry approaches, and biochemical and cell biological assays. We find the HIRA, but not the DAXX/ATRX, complex to specifically recognize H3.Y, explaining its presence in transcriptionally active euchromatic regions. Accordingly, H3.Y nucleosomes are enriched in the transcription-promoting FACT complex and depleted of repressive posttranslational histone modifications. H3.Y mutational gain-of-function analyses screens reveal an unexpected combinatorial amino acid sequence requirement for histone H3.3 interaction with DAXX but not HIRA, and for H3.3 recruitment to PML nuclear bodies. We demonstrate the importance and necessity of specific H3.3 core region and C-terminal amino acids in discriminating between distinct chaperone complexes. Further, ChIP-seq experiments reveal that in contrast to euchromatic HIRA-dependent deposition sites, human DAXX/ATRX-dependent regions of histone H3 variant incorporation are enriched in heterochromatic H3K9me3 and simple repeat sequences. These data demonstrate that H3.Y's unique amino acids allow a functional distinction between HIRA and DAXX binding and its consequent deposition into open chromatin.
2017-03-13 | GSE94034 | GEO
Project description:Nucleosomes package eukaryotic DNA and are composed of four different histone proteins, H3, H4, H2A and H2B. Histone H3 has two main variants, H3.1 and H3.3, which show different genomic localization patterns in animals. We profiled H3.1 and H3.3 variants in the genome of the plant Arabidopsis thaliana and show that the localization of these variants shows broad similarity in plants and animals, in addition to some unique features. H3.1 was enriched in silent areas of the genome including regions containing the repressive chromatin modifications H3 lysine 27 methylation, H3 lysine 9 methylation, and DNA methylation. In contrast, H3.3 was enriched in actively transcribed genes, especially peaking at the 3’ end of genes, and correlated with histone modifications associated with gene activation such as histone H3 lysine 4 methylation, and H2B ubiquitylation, as well as by RNA Pol II occupancy. Surprisingly, both H3.1 and H3.3 were enriched on defined origins of replication, as was overall nucleosome density, suggesting a novel characteristic of plant origins. Our results are broadly consistent with the hypothesis that H3.1 acts as the canonical histone that is incorporated during DNA replication, whereas H3.3 acts as the replacement histone that can be incorporated outside of S-phase during chromatin disrupting processes like transcription. ChIP-seq - 4 samples: 2 experiment and 2 controls RNA-seq - 1 sample
2012-03-05 | E-GEOD-34840 | biostudies-arrayexpress
Project description:Comprehensive identification and characterization of the distribution of tri-methylated Histone H3 lysine 36 (H3K36me3)
| PRJDB2672 | ENA
Project description:Nucleosomes package eukaryotic DNA and are composed of four different histone proteins, H3, H4, H2A and H2B. Histone H3 has two main variants, H3.1 and H3.3, which show different genomic localization patterns in animals. We profiled H3.1 and H3.3 variants in the genome of the plant Arabidopsis thaliana and show that the localization of these variants shows broad similarity in plants and animals, in addition to some unique features. H3.1 was enriched in silent areas of the genome including regions containing the repressive chromatin modifications H3 lysine 27 methylation, H3 lysine 9 methylation, and DNA methylation. In contrast, H3.3 was enriched in actively transcribed genes, especially peaking at the 3’ end of genes, and correlated with histone modifications associated with gene activation such as histone H3 lysine 4 methylation, and H2B ubiquitylation, as well as by RNA Pol II occupancy. Surprisingly, both H3.1 and H3.3 were enriched on defined origins of replication, as was overall nucleosome density, suggesting a novel characteristic of plant origins. Our results are broadly consistent with the hypothesis that H3.1 acts as the canonical histone that is incorporated during DNA replication, whereas H3.3 acts as the replacement histone that can be incorporated outside of S-phase during chromatin disrupting processes like transcription.
2012-03-05 | GSE34840 | GEO
Project description:Histones and histone variants are essential components of the nuclear chromatin. While mass spectrometry has opened a large window to their characterization and functional studies, their identification from proteomic data remains challenging. Indeed, the current interpretation of mass spectrometry data relies on public databases which are either not exhaustive (Swiss-Prot) or contain many redundant entries (UniProtKB or NCBI). Currently, no protein database is ideally suited for the analysis of histones and the complex array of mammalian histone variants. Here, we propose two proteomics-oriented manually curated databases for mouse and human histone variants. Several histone variants, which had so far only been inferred by homology or detected at the RNA level, were detected by mass spectrometry, confirming the existence of their protein form.
2017-01-11 | PXD005489 | Pride
Project description:Replication-independent deposition of histone variant H3.3 into chromatin is essential for many biological processes, including development, oogenesis and nuclear reprogramming. Unlike replication-dependent H3.1/2 isoforms, H3.3 is expressed throughout the cell cycle and becomes enriched in postmitotic cells with age. However, lifelong dynamics of H3 variant replacement and the impact of this process on chromatin organization remain largely undefined. To address this, we investigated genome-wide changes in histone H3 variants composition and H3 modification abundances throughout the lifespan in mice using quantitative mass spectrometry (MS) – based middle-down proteomics strategy. Using middle-down MS we demonstrate that H3.3 accumulates in the chromatin of various somatic mouse tissues throughout life, resulting in near complete replacement of H3.1/2 isoforms by the late adulthood. Accumulation of H3.3 is associated with profound changes in the global level of H3 methylation. H3.3-containing chromatin exhibits distinct stable levels of H3R17me2 and H3K36me2, different from those on H3.1/H3.2-containing chromatin, indicating a direct link between H3 variant exchange and histone methylation dynamics with age. In summary, our study provides the first time comprehensive characterization of dynamic changes in the H3 modification landscape during mouse lifespan and links these changes to the age-dependent accumulation of histone variant H3.3.
2017-07-28 | PXD005300 | Pride
Project description:Bivalency - Histone H3 Lysine4 and Histone H3 Lysine27 Methylation Dynamics
| PRJNA311514 | ENA