Project description:Histone modifications are critical for regulating chromatin structure and gene expression. Dysregulation of histone modifications likely contributes to disease states and cancer. Depletion of the chromatin-binding protein BRWD3, a known substrate-specificity factor of the Cul4-DDB1 E3 ubiquitin ligase complex, results in increased in H3K4me1 levels. The underlying mechanism linking BRWD3 and H3K4 methylation, however, has yet to be defined. Here, we show that depleting BRWD3 not only causes an increase in H3K4me1 levels, but also causes a decrease in H3K4me3 levels, indicating that BRWD3 influences H3K4 methylation more broadly. Using immunoprecipitation coupled to quantitative mass spectrometry, we identified an interaction between BRWD3 and the H3K4-specific demethylase 5 (KDM5/Lid), an enzyme that removes tri- and di- methyl marks from H3K4. Moreover, analysis of ChIP-seq data revealed that BRWD3 and KDM5 are significantly co-localized throughout the genome and that sites of H3K4me3 are highly enriched at BRWD3 binding sites. We show that BRWD3 promotes K48-linked polyubiquitination and degradation of KDM5 and that KDM5 degradation is dependent on both BRWD3 and Cul4. Critically, depleting KDM5 fully restores altered H3K4me3 levels and partially restores H3K4me1 levels upon BRWD3 depletion. Together, our results demonstrate that BRWD3 regulates KDM5 activity to balance H3K4 methylation levels.
Project description:Histone modifications are critical for regulating chromatin structure and gene expression. Dysregulation of histone modification levels may contribute to disease development and cancer. Therefore, understanding histone modifications is essential for development and disease. The chromatin-binding protein BRWD3, a known substrate-specificity factor of the Cul4-DDB1 E3 ubiquitin ligase complex, is required for maintaining active histone modification levels. Loss of BRWD3 function causes an increase in H3K4me1 levels. The underline mechanism, however, is unknown. We found that BRWD3 depletion also causes a decrease in H3K4me3 levels. To reveal the mechanism by which BRWD3 regulates the H3K4 methylation levels, we performed BRWD3-IP mass-spectrometry. We identified an interaction between BRWD3 and the lysine-specific demethylase 5 (KDM5/Lid), an enzyme that removes tri- and di- methyl marks from lysine 4 on histone H3. Moreover, analysis of ChIP-seq data revealed that BRWD3 and KDM5 are significantly co-localized throughout the genome. We show that BRWD3 promotes K48-linked ubiquitination of KDM5. Consistent with this, KDM5/Lid is rapidly degraded in a proteasome-dependent manner with a half-life of less than 30 mins. Critically, KDM5/Lid degradation is dependent on both BRWD3 and Cul4. In addition, we have found that BRWD3 is suppressor of Position-effect variegation (PEV). Loss of a single copy of KDM5, however, partially rescues the the BRWD3 PEV phenotype. Our results suggest that BRWD3 targets KDM5/Lid for degradation to ensure the balance of H3K4me levels.
Project description:Histone modifications are critical for regulating chromatin structure and gene expression. Dysregulation of histone modifications likely contributes to disease states and cancer. Depletion of the chromatin-binding protein BRWD3, a known substrate-specificity factor of the Cul4-DDB1 E3 ubiquitin ligase complex, results in increased in H3K4me1 levels. The underlying mechanism linking BRWD3 and H3K4 methylation, however, has yet to be defined. Here, we show that depleting BRWD3 not only causes an increase in H3K4me1 levels, but also causes a decrease in H3K4me3 levels, indicating that BRWD3 influences H3K4 methylation more broadly. Using immunoprecipitation coupled to quantitative mass spectrometry, we identified an interaction between BRWD3 and the H3K4-specific demethylase 5 (KDM5/Lid), an enzyme that removes tri- and di- methyl marks from H3K4. Moreover, analysis of ChIP-seq data revealed that BRWD3 and KDM5 are significantly co- localized throughout the genome and that sites of H3K4me3 are highly enriched at BRWD3 binding sites. We show that BRWD3 promotes K48-linked polyubiquitination and degradation of KDM5 and that KDM5 degradation is dependent on both BRWD3 and Cul4. Critically, depleting KDM5 fully restores altered H3K4me3 levels and partially restores H3K4me1 levels upon BRWD3 depletion. Together, our results demonstrate that BRWD3 regulates KDM5 activity to balance H3K4 methylation levels.
Project description:Loss of function mutations in the histone methyltransferase KMT2D are common in lymphomas but difficult to target. We reported targeting KDM5 restores epigenetic balance in germinal centre (GC) lymphomas. Here, we show the KDM5 family are over-expressed in mantle cell lymphoma (MCL). GS716054, a pro-drug, increases H3K4 trimethylation (H3K4me3) and kills MCL cells including TP53 mutated cells via suppression of the MYC pathway. It can overcome ibrutinib resistance and synergises with ibrutinib. These data suggest a possible role for KDM5-inhibitors in advanced MCL.
Project description:Tri-methylation on histone H3 lysine 4 (H3K4me3) is enriched near transcription start sites and correlates with active transcription. Like other histone marks, methylation on H3K4 is catalyzed by the respective methyltransferases and erased by demethylases. Lysine demethylase 5 (KDM5) family of Fe (II) and α-ketoglutarate-dependent dioxygenases removes the methyl groups from H3K4me3. All four family members of KDM5 demethylases (KDM5A-D) share sequence identity, have similar in vitro kinetic parameters, and display functional redundancy. To determine the effects of complete depletion of KDM5 activity, we treated MCF7 cells with DMSO, or two pan-KDM5 specific inhibitors, KDM5-C70 (our lab code 443) and CPI-48 (our lab code 278) and performed RNA sequencing to determine gene expression changes after KDM5 inhibitor treatment.
Project description:To determine which genes affected by loss of KDM5 in adults were direct targets, we carried out KDM5 ChIP-seq analyses. To valide this data, we utilized a previously generated fly strain in which the sole source of KDM5 is from a transgene expressing an HA tagged form of KDM5 expressed under the control of its endogenous promoter. Comparing genome-wide gene expression and KDM5 binding analyses in Drosophila adults, we demonstrate the primary function of KDM5 in adults is to activate gene expression KDM5. To investigate the link between KDM5 and H3K4me3, we carried out anti-H3K4me3 ChIP-seq from wildtype adults . Genome-wide, KDM5 and H3K4me3 peaks showed a similar distribution, with both peaking at the transcription start site (TSS) showed a striking overlap with the presence of H3K4me3. Examination of KDM5 binding and histone H3K4me3 modifications in drosophila adults
Project description:Loss of function mutations within KMT2D are a striking feature of the germinal centre lymphomas, with lesions present in 80% of Follicular Lymphoma (FL) and 30% of Diffuse Large B-cell Lymphoma (DLBCL), resulting in decreased H3K4 methylation and altered gene expression. The KDM5 family normally maintains homeostasis through demethylating H3K4me3/2, thus negatively regulating gene expression. We hypothesised that inhibition of KDM5 may re-establish H3K4 methylation and restore the expression of genes repressed upon loss of KMT2D. Using a selective inhibitor of the KDM5 family we were able to increase H3K4me3 levels in DLBCL cell lines, predominantly at gene promoters, ultimately leading to decreased proliferation and cell death in KMT2D mutant cell lines. This appeared to be driven by an increase in the expression of negative regulators of B cell survival pathways, many of which have previously been described as targets of KMT2D and CREBBP, resulting in diminished BCR signalling. We also observed decreased BCL2 expression in all examined t(14;18) positive cell lines, alongside changes in other BCL2 family members in sensitive cell lines. KDM5 sensitivity was confirmed to be dependent on the presence of KMT2D mutations by generating de novo KMT2D mutant cell lines and correcting naturally mutant cell lines, which displayed greater and lesser sensitivity to KDM5 inhibition respectively. KDM5 inhibition may therefore be an effective therapeutic strategy for ameliorating KMT2D loss of function mutations in malignancies such as germinal centre lymphomas.
Project description:Loss of function mutations within KMT2D are a striking feature of the germinal centre lymphomas, with lesions present in 80% of Follicular Lymphoma (FL) and 30% of Diffuse Large B-cell Lymphoma (DLBCL), resulting in decreased H3K4 methylation and altered gene expression. The KDM5 family normally maintains homeostasis through demethylating H3K4me3/2, thus negatively regulating gene expression. We hypothesised that inhibition of KDM5 may re-establish H3K4 methylation and restore the expression of genes repressed upon loss of KMT2D. Using a selective inhibitor of the KDM5 family we were able to increase H3K4me3 levels in DLBCL cell lines, predominantly at gene promoters, ultimately leading to decreased proliferation and cell death in KMT2D mutant cell lines. This appeared to be driven by an increase in the expression of negative regulators of B cell survival pathways, many of which have previously been described as targets of KMT2D and CREBBP, resulting in diminished BCR signalling. We also observed decreased BCL2 expression in all examined t(14;18) positive cell lines, alongside changes in other BCL2 family members in sensitive cell lines. KDM5 sensitivity was confirmed to be dependent on the presence of KMT2D mutations by generating de novo KMT2D mutant cell lines and correcting naturally mutant cell lines, which displayed greater and lesser sensitivity to KDM5 inhibition respectively. KDM5 inhibition may therefore be an effective therapeutic strategy for ameliorating KMT2D loss of function mutations in malignancies such as germinal centre lymphomas.
Project description:The goal of this study was to generate a Drosophila model of intellectual disability caused by mutations in kdm5. RNA-seq was used to define the transcriptional defects of a mutation in Drosophila that is analogous to a human intellectual disability-associated allele, kdm5[A512p]. These data revealed a total of 1609 dysregulated genes, 778 of which were upregulated and 831 were downregulated. To determine whether these transcriptional defects were due to the loss of KDM5-induced histone demethylation, we also carried out RNA-seq from a enzymatic inactive strain, kdm5[Jmjc*]. These data revealed a striking similarity between the two datasets and suggest that the primary defect of KDM5[A512P] is loss of histone demethylase activity.
Project description:To determine microbiota composition associated with loss of KDM5 in intestine, we carried out 16S rRNA seq analyses of dissected intestine from wildtype and kdm5 mutant. [GSM2628181-GSM2628190]. A total of 78 operational taxonomic units (OTUs) were identified in the sequence data. There were about 15 genera much less abundant in kdm5 mutant compared to wildtype. The kdm5 mutant were sensitive to pathogen. To confirm the microbiota associated with loss of KDM5 in intestine, 16S rRNA of new flies were sequenced and analyzed by Majorbio Bio-Pharm Technology Co. Ltd. (Shanghai, China) [GSM3243472-GSM3243481]. A total of 107 operational taxonomic units (OTUs) were identified in the sequence data. There were about 20 genera much less abundant in kdm5 mutant compared to wildtype. To confirm the microbiota associated with loss of KDM5 drosophila feeding with Lactobacillus plantarum, 16S rRNA of kdm5 mutant flies were sequenced and analyzed by Novogene Bioinformatics Technology Co., Ltd. (Tianjin, China) [GSM3263522-GSM3263527]. A total of 92 operational taxonomic units (OTUs) were identified in the sequence data. To confirm the microbiota associated with KDM5 knockdown in intestine, 16S rRNA of Myo1A-Gal4TS/+ and Myo1A-Gal4TS/+;+/kdm5RNAi flies were sequenced and analyzed by Biomarker Co. Ltd. (Beijing, China). [GSM3507915-GSM3507924]. A total of 50 operational taxonomic units (OTUs) were identified in the sequence data. There was a significant different based on the genus level between two groups.