MLL3/4 Direct a Gene-expression Program Required for Efficient Platelet Production [RNA-seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE255020 | GEO | 2025/05/13
REPOSITORIES: GEO
Similar Datasets
Project description:MLL3 and MLL4 are the mjor histone lysine methyltransferases for the active enhance mark H3K4me1. We observed that platelet counts are dramatically decreased in the MLL3/4 SET-deletion mice. Cultured megakaryocytes from MLL3/4 SET-deletion fetal liver were used for RNA-seq analysis to investigate the changes in gene expression. We also performed CUT&RUN analysis to examine the changes in enhncers that may regulate those gene expression. We included PTIP in this study, because it is an important co-factor of the MLL3/4 complex, and knockout of PTIP also leads to decreased platelet production.
2025-05-13 | GSE255021 | GEO
Project description:Class-switch recombination (CSR) diversifies antibodies for productive immune responses while maintaining stability of the B cell genome. Transcription at the immunoglobulin heavy-chain (Igh) locus targets CSRassociated DNA damage and is promoted by the BRCT domain-containing PTIP protein. Although PTIP is a unique component of the MLL3/MLL4 chromatin-modifying complex, the mechanisms for how PTIP promotes transcription remain unclear. Here we dissect the minimal structural requirements of PTIP and its different protein complexes using quantitative proteomics in primary lymphocytes. We find that PTIP functions in transcription and CSR separately from its association with the MLL3/MLL4 complex and from its localization to sites of DNA damage. We identify a tandem BRCT domain of PTIP that is sufficient for CSR and identify PA1 as its main functional protein partner. Collectively, we provide genetic and biochemical evidence that a PTIP-PA1 subcomplex functions independently from the MLL3/MLL4 complex to mediate transcription during CSR. These results further our understanding of how multi-functional chromatin-modifying complexes are organized by subcomplexes that harbor unique and distinct activities. Genome-wide analysis of histone modifications in PA1-WT and -KO mouse activated B cells
2015-12-12 | E-GEOD-75930 | biostudies-arrayexpress
Project description:Class-switch recombination (CSR) diversifies antibodies for productive immune responses while maintaining stability of the B cell genome. Transcription at the immunoglobulin heavy-chain (Igh) locus targets CSRassociated DNA damage and is promoted by the BRCT domain-containing PTIP protein. Although PTIP is a unique component of the MLL3/MLL4 chromatin-modifying complex, the mechanisms for how PTIP promotes transcription remain unclear. Here we dissect the minimal structural requirements of PTIP and its different protein complexes using quantitative proteomics in primary lymphocytes. We find that PTIP functions in transcription and CSR separately from its association with the MLL3/MLL4 complex and from its localization to sites of DNA damage. We identify a tandem BRCT domain of PTIP that is sufficient for CSR and identify PA1 as its main functional protein partner. Collectively, we provide genetic and biochemical evidence that a PTIP-PA1 subcomplex functions independently from the MLL3/MLL4 complex to mediate transcription during CSR. These results further our understanding of how multi-functional chromatin-modifying complexes are organized by subcomplexes that harbor unique and distinct activities.
2015-12-12 | GSE75930 | GEO
Project description:Histone H3 lysine 4 (H3K4) can be mono-, di-, and trimethylated by members of the COMPASS (COMplex of Proteins ASsociated with Set1) family from yeast to human and these modifications can be found at distinct regions of the genome. Monomethylation of histone H3K4 (H3K4me1) is relatively more enriched at metazoan enhancer regions compared to trimethylated histone H3K4 (H3K4me3), which are found at transcription start sites in all eukaryotes. Our recent studies in Drosophila demonstrated that the Trithorax-related (Trr) branch of the COMPASS family regulates enhancer activity and is responsible for the implementation of H3K4me1 at these regions. There are six COMPASS family members in mammals, two of which, MLL3 and MLL4, are most closely related to Drosophila Trr. Here, we use ChIP-seq of this class of COMPASS family members in both human HCT116 cells and mouse embryonic stem cells and find that MLL4 is preferentially found at enhancer regions. MLL3 and MLL4 are frequently mutated in cancer, and indeed, the widely used HCT116 cancer cell line contains inactivating mutations in the MLL3 gene. Using HCT116 cells in which MLL4 has also been knocked out, we demonstrate that MLL4 is a major regulator of H3K4me1 in these cells, with the greatest loss of monomethylation at enhancer regions. Moreover, we found a redundant role between Mll3 and Mll4 in enhancer H3K4 monomethylation in mouse embryonic fibroblast (MEF) cells. These findings suggest that mammalian MLL3/MLL4 function in the regulation of enhancer activity and enhancer-promoter communication during gene expression and that mutations of MLL3 and MLL4 found in cancer could exert their properties through enhancer malfunction. ChIP-Seq in mouse embryonic stem (mES) cells for MLL4. ChIP-seq of MLL4 and p300 in human parental HCT116 cells. ChIP-seq of H3K4me1, H3K4me2 and H3K4me3 in parental HCT116 cells and HCT116 cells with Mll4∆set.
2013-09-30 | E-GEOD-51176 | biostudies-arrayexpress
Project description:Programmed genetic rearrangements in lymphocytes require transcription at antigen receptor genes to promote accessibility for initiating double-strand break (DSB) formation critical for DNA recombination and repair. Here we show that activated B cells deficient in the PTIP component of the MLL3 (mixed-lineage leukemia 3) /MLL4 complex display impaired histone methylation (H3K4me3) and transcription initiation of downstream switch regions at the immunoglobulin heavy-chain (Igh) locus leading to defective immunoglobulin class-switching. We also show that PTIP accumulation at DSBs contributes to class-switch recombination (CSR) and genome stability independently from Igh switch transcription. These results demonstrate that PTIP promotes specific chromatin changes that control the accessibility of the Igh locus to CSR, and suggest a non-redundant role for the MLL3/MLL4 complex in altering antibody effector function. Genome-wide analysis of histone modifications, PTIP, and Pol II in PTIP-WT and PTIP-KO mouse activated B cells.
2010-08-25 | E-GEOD-20852 | biostudies-arrayexpress
Project description:Enhancers play a key role in regulating cell type-specific gene expression and are marked by histone modifications such as methylation and acetylation. Mono-methylation of lysine 4 on histone H3 (H3K4me1) initially primes enhancers, preceding enhancer activation via acetylation of lysine 27 on histone H3 (H3K27ac). MLL4 is a major enhancer H3K4 mono-methyltransferase with partial functional redundancy with MLL3. However, how H3K4me1 affects enhancer regulation in cell differentiation has remained unclear. By screening several lysine-to-methionine mutants of H3.3, we first found that depletion of H3K4 methylation by H3.3K4M mutation severely impairs adipogenesis in culture. Using tissue-specific expression of H3.3K4M in mice, we further demonstrate that H3.3K4M inhibits adipose tissue and muscle development in vivo. Mechanistically, H3.3K4M destabilizes MLL3/4 proteins but not other members of the mammalian Set1-like H3K4 methyltransferase family and prevents MLL3/4-mediated enhancer activation in adipogenesis. Using tissue-specific deletion of the enzymatic SET domain of MLL3/4 in mice, we also show that deletion of the SET domain prevents adipose tissue and muscle development in vivo and inhibits adipogenesis by destabilizing MLL3/4 in vitro. Notably, H3.3K4M expression mimics MLL3/4 SET domain deletion in preventing adipogenesis. Interestingly, H3.3K4M does not affect adipose tissue maintenance and function, suggesting that MLL3/4-mediated H3K4 methylation is dispensable for the maintenance and function of differentiated adipocytes. Together, our findings suggest that H3.3K4M targets MLL3/4 to prevent enhancer activation in adipogenesis.
2018-10-25 | GSE110972 | GEO
Project description:Programmed genetic rearrangements in lymphocytes require transcription at antigen receptor genes to promote accessibility for initiating double-strand break (DSB) formation critical for DNA recombination and repair. Here we show that activated B cells deficient in the PTIP component of the MLL3 (mixed-lineage leukemia 3) /MLL4 complex display impaired histone methylation (H3K4me3) and transcription initiation of downstream switch regions at the immunoglobulin heavy-chain (Igh) locus leading to defective immunoglobulin class-switching. We also show that PTIP accumulation at DSBs contributes to class-switch recombination (CSR) and genome stability independently from Igh switch transcription. These results demonstrate that PTIP promotes specific chromatin changes that control the accessibility of the Igh locus to CSR, and suggest a non-redundant role for the MLL3/MLL4 complex in altering antibody effector function.
2010-08-25 | GSE20852 | GEO
Project description:Histone H3K4me1/2 methyltransferases MLL3/MLL4 and H3K27 acetyltransferases CBP/p300 are major enhancer epigenomic writers. To understand how these epigenomic writers orchestrate enhancer landscapes during cell differentiation, we have profiled genomic binding of MLL4, CBP, lineage-determining transcription factors, as well as transcriptome and epigenome during adipogenesis of immortalized preadipocytes derived from mouse brown adipose tissue (BAT). We show that MLL4 and CBP drive the dynamic enhancer epigenome, which correlates with the dynamic transcriptome. MLL3/MLL4 are required for CBP/p300 binding on enhancers activated during adipogenesis. Further, we show that MLL4 and CBP identify super-enhancers of adipogenesis and that MLL3/MLL4 are required for the formation of super-enhancers. Finally, in brown adipocytes differentiated in culture, MLL4 identifies primed super-enhancers of genes fully activated in BAT such as the thermogenic Ucp1. Comparison of MLL4-defined super-enhancers in brown and white adipogenesis predicted a list of brown-specific super-enhancers SEs associated genes that are likely to be important to BAT functions. These results establish MLL3/MLL4 and CBP/p300 as master enhancer epigenomic writers and suggest that enhancer-priming by MLL3/MLL4 followed by enhancer-activation by CBP/p300 sequentially shape dynamic enhancer landscapes during cell differentiation. Our data also provide a rich resource for understanding epigenomic regulation of brown adipogenesis.
2017-01-01 | GSE74189 | GEO
Project description:Histone H3 lysine 4 (H3K4) can be mono-, di-, and trimethylated by members of the COMPASS (COMplex of Proteins ASsociated with Set1) family from yeast to human and these modifications can be found at distinct regions of the genome. Monomethylation of histone H3K4 (H3K4me1) is relatively more enriched at metazoan enhancer regions compared to trimethylated histone H3K4 (H3K4me3), which are found at transcription start sites in all eukaryotes. Our recent studies in Drosophila demonstrated that the Trithorax-related (Trr) branch of the COMPASS family regulates enhancer activity and is responsible for the implementation of H3K4me1 at these regions. There are six COMPASS family members in mammals, two of which, MLL3 and MLL4, are most closely related to Drosophila Trr. Here, we use ChIP-seq of this class of COMPASS family members in both human HCT116 cells and mouse embryonic stem cells and find that MLL4 is preferentially found at enhancer regions. MLL3 and MLL4 are frequently mutated in cancer, and indeed, the widely used HCT116 cancer cell line contains inactivating mutations in the MLL3 gene. Using HCT116 cells in which MLL4 has also been knocked out, we demonstrate that MLL4 is a major regulator of H3K4me1 in these cells, with the greatest loss of monomethylation at enhancer regions. Moreover, we found a redundant role between Mll3 and Mll4 in enhancer H3K4 monomethylation in mouse embryonic fibroblast (MEF) cells. These findings suggest that mammalian MLL3/MLL4 function in the regulation of enhancer activity and enhancer-promoter communication during gene expression and that mutations of MLL3 and MLL4 found in cancer could exert their properties through enhancer malfunction.
2013-09-30 | GSE51176 | GEO
Project description:H3K4me1 methyltransferases MLL3 (KMT2C) and MLL4 (KMT2D) are critical for enhancer activation, cell differentiation and development. However, roles of MLL3/4 enzymatic activities and MLL3/4-mediated enhancer H3K4me1 in these processes remain unclear. Here, we report that constitutive elimination of both MLL3 and MLL4 enzymatic activities prevents initiation of gastrulation and leads to early embryonic lethality in mice. However, selective elimination of MLL3/4 enzymatic activities in embryonic, but not extraembryonic, lineages leaves gastrulation largely intact. Consistently, embryonic stem cells (ESCs) lacking MLL3/4 enzymatic activities can differentiate towards the three embryonic germ layers but show aberrant differentiation to extraembryonic endoderm and trophectoderm. The failure in extraembryonic endoderm differentiation can be attributed to markedly reduced enhancer-binding of the lineage-determining transcription factor GATA6. Furthermore, we show that MLL3/4-catalyzed H3K4me1 is largely dispensable for enhancer activation during ESC differentiation. Together, our findings suggest a lineage-selective, but enhancer activation-independent, role of MLL3/4 methyltransferase activities in early embryonic development and ESC differentiation.
2023-01-25 | GSE154475 | GEO