Project description:SFMBT1 is a poorly characterized mammalian MBT domain-containing protein homologous to Drosophila SFMBT, a Polycomb group protein involved in epigenetic regulation of gene expression. Here, we show that SFMBT1 regulates transcription in somatic cells and during spermatogenesis through the formation of a stable complex with LSD1 and CoREST. When bound to its gene targets, SFMBT1 recruits its associated proteins and causes chromatin compaction and transcriptional repression. SFMBT1, LSD1, and CoREST share a large fraction of target genes including those encoding replication-dependent histones. Simultaneous occupancy of histone genes by SFMBT1, LSD1, and CoREST is regulated during the cell cycle and correlates with the loss of RNA polymerase II at these promoters during G2, M, and G1. The interplay between the repressive SFMBT1M-bM-^@M-^SLSD1M-bM-^@M-^SCoREST complex and RNA polymerase II contributes to the timely transcriptional regulation of histone genes in human cells. SFMBT1, LSD1, and CoREST also form a stable complex in germ cells and their chromatin binding activity is regulated during spermatogenesis. RNA-seq in HeLaS3 cells ctrl compared to triple knockdown for SFMBT1, CoREST, and LSD1
Project description:SFMBT1 is a poorly characterized mammalian MBT domain-containing protein homologous to Drosophila SFMBT, a Polycomb group protein involved in epigenetic regulation of gene expression. Here, we show that SFMBT1 regulates transcription in somatic cells and during spermatogenesis through the formation of a stable complex with LSD1 and CoREST. When bound to its gene targets, SFMBT1 recruits its associated proteins and causes chromatin compaction and transcriptional repression. SFMBT1, LSD1, and CoREST share a large fraction of target genes including those encoding replication-dependent histones. Simultaneous occupancy of histone genes by SFMBT1, LSD1, and CoREST is regulated during the cell cycle and correlates with the loss of RNA polymerase II at these promoters during G2, M, and G1. The interplay between the repressive SFMBT1–LSD1–CoREST complex and RNA polymerase II contributes to the timely transcriptional regulation of histone genes in human cells. SFMBT1, LSD1, and CoREST also form a stable complex in germ cells and their chromatin binding activity is regulated during spermatogenesis.
Project description:SFMBT1 is a poorly characterized mammalian MBT domain-containing protein homologous to Drosophila SFMBT, a Polycomb group protein involved in epigenetic regulation of gene expression. Here, we show that SFMBT1 regulates transcription in somatic cells and during spermatogenesis through the formation of a stable complex with LSD1 and CoREST. When bound to its gene targets, SFMBT1 recruits its associated proteins and causes chromatin compaction and transcriptional repression. SFMBT1, LSD1, and CoREST share a large fraction of target genes including those encoding replication-dependent histones. Simultaneous occupancy of histone genes by SFMBT1, LSD1, and CoREST is regulated during the cell cycle and correlates with the loss of RNA polymerase II at these promoters during G2, M, and G1. The interplay between the repressive SFMBT1–LSD1–CoREST complex and RNA polymerase II contributes to the timely transcriptional regulation of histone genes in human cells. SFMBT1, LSD1, and CoREST also form a stable complex in germ cells and their chromatin binding activity is regulated during spermatogenesis.
Project description:SFMBT1 is a poorly characterized mammalian MBT domain-containing protein homologous to Drosophila SFMBT, a Polycomb group protein involved in epigenetic regulation of gene expression. Here, we show that SFMBT1 regulates transcription in somatic cells and during spermatogenesis through the formation of a stable complex with LSD1 and CoREST. When bound to its gene targets, SFMBT1 recruits its associated proteins and causes chromatin compaction and transcriptional repression. SFMBT1, LSD1, and CoREST share a large fraction of target genes including those encoding replication-dependent histones. Simultaneous occupancy of histone genes by SFMBT1, LSD1, and CoREST is regulated during the cell cycle and correlates with the loss of RNA polymerase II at these promoters during G2, M, and G1. The interplay between the repressive SFMBT1M-bM-^@M-^SLSD1M-bM-^@M-^SCoREST complex and RNA polymerase II contributes to the timely transcriptional regulation of histone genes in human cells. SFMBT1, LSD1, and CoREST also form a stable complex in germ cells and their chromatin binding activity is regulated during spermatogenesis. ChIP-seq in HeLaS3 at different phases of the cell cycle and primary germ cells at different stages of spermatogenesis using antibodies against endogenous proteins
Project description:Long intergenic noncoding RNAs (lincRNAs) regulate chromatin states and epigenetic inheritance. Here we show that the lincRNA HOTAIR serves as a scaffold for at least two distinct histone modification complexes. A 5’ domain of HOTAIR binds Polycomb Repressive Complex 2 (PRC2) while a 3’ domain of HOTAIR binds the LSD1/CoREST/REST complex. The ability to tether two distinct complexes enables RNA-mediated assembly of PRC2 and LSD1, and coordinates targeting of PRC2 and LSD1 to chromatin for coupled histone H3 lysine 27 methylation and lysine 4 demethylation. Our results suggest that lincRNAs may serve as scaffolds by providing binding surfaces to assemble select histone modification enzymes, and thereby specify the pattern of histone modifications on target genes. Coordinate loss of SUZ12 and LSD1 occupancy caused by HOTAIR knockdown were concentrated in proximal promoters of HOXD genes. These regions correspondingly lost H3K27me3 and gained H3K4me2, the respective histone methylation products of PRC2 and LSD1 complexes. Comparison occupancy of LSD1 and SUZ12 of siGFP and siHOTAIR foreskin fibroblasts on HOX tiling array. Human foreskin fibroblasts were transfected with siGFP or siHOTAIR. The cells were harvested and ChIP analysis with anti-H3K4me2, anti-LSD1 and anti-SUZ12 antibodies was performed.
Project description:How cell-type-specific chromatin landscapes emerge and progress during metazoan ontogenesis remains an important question. Transcription factors are expressed in a cell type-specific manner and recruit chromatin-regulatory machinery to specific genomic loci. In contrast, most chromatin-regulatory proteins are expressed broadly and are assumed to exert the same intrinsic function across cell types. However, human genetics studies have revealed an unexpected vulnerability of neurodevelopment to chromatin factor mutations with unknown mechanisms. Here, we report that 13 chromatin regulators undergo evolutionary-conserved neuron-specific splicing events involving microexons. Two of these 13 factors are integral components of a histone H3K4 demethylase complex; the catalytic subunit LSD1 and an H3K4me0-reader protein PHF21A. We found that canonical PHF21A (PHF21A-c) binds to DNA by AT-hook motif, and the neuronal counterpart PHF21A-n lacks this DNA-binding function. PHF21A-n showed significantly weaker affinity to the histone H3 tail compared to PHF21A-c. Furthermore, neuronal LSD1 splicing led to reduced affinity of LSD1 to the nucleosome. In-vitro reconstitution of the canonical and neuronal PHF21A-LSD1 complexes, combined with in-vivo methylation mapping, identified the neuronal complex as a hypomorphic H3K4 demethylating machinery with reduced nucleosome engagement. The neuronal PHF21A, albeit its weaker nucleosome binding, is necessary for normal gene expression and H3K4 landscape in developing neurons. Thus, ubiquitously expressed chromatin regulatory complexes can exert neuron-specific functions via alternative splicing of their subunits.
Project description:Long intergenic noncoding RNAs (lincRNAs) regulate chromatin states and epigenetic inheritance. Here we show that the lincRNA HOTAIR serves as a scaffold for at least two distinct histone modification complexes. A 5’ domain of HOTAIR binds Polycomb Repressive Complex 2 (PRC2) while a 3’ domain of HOTAIR binds the LSD1/CoREST/REST complex. The ability to tether two distinct complexes enables RNA-mediated assembly of PRC2 and LSD1, and coordinates targeting of PRC2 and LSD1 to chromatin for coupled histone H3 lysine 27 methylation and lysine 4 demethylation. Our results suggest that lincRNAs may serve as scaffolds by providing binding surfaces to assemble select histone modification enzymes, and thereby specify the pattern of histone modifications on target genes. LSD1 and SUZ12 co-occupied on 721 genes in human foreskin fibroblasts. Coordinate loss of SUZ12 and LSD1 occupancy was caused by HOTAIR knockdown. Comparison occupancy of LSD1 and SUZ12 of siGFP and siHOTAIR foreskin fibroblasts on human HG18 promoter arrays. Human foreskin fibroblasts were transfected with siGFP or siHOTAIR. The cells were harvested and ChIP analysis with anti-LSD1 and anti-SUZ12 antibodies was performed.
Project description:LSD1 is involved in multiple essential roles in mammalian biology and various modes of LSD1 regulation are described ranging from interaction with specific coregulators to distinct post translational modifications. Here we show that NEK6 positively influences LSD1 activity and we observe a strong colocalization of NEK6 and LSD1 at distinct chromatin sub-compartments (CSCs). We further demonstrate that LSD1 is a substrate for NEK6-mediated phosphorylation at the highly conserved, but intrinsic disordered region (IDR) of LSD1, which shows phase separation behaviour in-vitro and in cells. Furthermore, the IDR of LSD1 is important for LSD1 activity and functions to co-compartmentalize histone tails. Our data suggest that LSD1 and NEK6 form distinct CSCs in part through the formation of phase-separated condensates. The subsequent phosphorylation of LSD1 by NEK6 within these CSCs aids to concentrate more LSD1 leading to co-compartmentalisation of histone substrates, which is imperative for dynamic and robust control of transcription.