Project description:This SuperSeries is composed of the following subset Series: GSE34282: Effects of Mysm1 deficiency on gene expression across a range of mouse tissues and cell types (tissue data) GSE34284: Effects of Mysm1 deficiency on gene expression across a range of mouse tissues and cell types (cell data) Refer to individual Series
Project description:MYSM1 is a transcriptional regulator essential for HSC function and hematopoiesis. We established that HSC dysfunction in Mysm1-deficiency is driven by p53 stress response, however, the molecular function of MYSM1 as a transcriptional activator and its essential role in p53 stress response repression remain difficult to reconcile. Here, we performed genome-wide analyses of MYSM1-regulated genes in hematopoietic stem and progenitor cells (HSPCs). This included RNA-Seq of sorted Mysm1-deficient mouse HSCs and MPPs, and ChIP-Seq mapping of MYSM1 DNA-binding sites in hematopoietic progenitor cell lines. We demonstrate a direct role for MYSM1 in the regulation of genes encoding protein components of the ribosome (RP-genes) and other regulators of translation. Mechanistically, the dysregulation of RP-genes in Mysm1-deficiency was upstream of p53-activation and associated with reduced HSCs protein synthesis rates and p53-dependent anemia.
Project description:MYSM1 is a transcriptional regulator essential for HSC function and hematopoiesis. We established that HSC dysfunction in Mysm1-deficiency is driven by p53 stress response, however, the molecular function of MYSM1 as a transcriptional activator and its essential role in p53 stress response repression remain difficult to reconcile. Here, we performed genome-wide analyses of MYSM1-regulated genes in hematopoietic stem and progenitor cells (HSPCs). This included RNA-Seq of sorted Mysm1-deficient mouse HSCs and MPPs, and ChIP-Seq mapping of MYSM1 DNA-binding sites in hematopoietic progenitor cell lines. We demonstrate a direct role for MYSM1 in the regulation of genes encoding protein components of the ribosome (RP-genes) and other regulators of translation. Mechanistically, the dysregulation of RP-genes in Mysm1-deficiency was upstream of p53-activation and associated with reduced HSCs protein synthesis rates and p53-dependent anemia.
Project description:Stem cell differentiation and lineage specification depend on coordinated programs of gene expression, but our knowledge of the chromatin modifying factors regulating these events remains incomplete. Ubiquitination of histone H2A (H2A-K119u) is a common chromatin modification associated with gene silencing, and controlled by the ubiquitin-ligase polycomb repressor complex 1 (PRC1) and H2A-deubiquitinating enzymes (H2A-DUBs). The roles of H2A-DUBs in mammalian development, stem cells, and haematopoiesis have not been addressed. Here we characterized an H2A-DUB targeted mouse line Mysm1-tm1a/tm1a and demonstrated defects in bone marrow haematopoiesis, resulting in lymphopenia, anemia, and thrombocytosis. Development of lymphocytes was impaired from the earliest stages of their differentiation; and there was also a depletion of erythroid cells and a defect in erythroid progenitor function. These phenotypes were due to a cell-intrinsic requirement for Mysm1 in the bone marrow. Importantly, Mysm1-tm1a/tm1a haematopoietic stem cells were functionally impaired, and this was associated with elevated levels of reactive oxygen species, γH2AX DNA damage marker, and p53 protein in the haematopoietic progenitors. Overall these data establish a role for Mysm1 in the maintenance of bone marrow stem cell function, in the control of oxidative stress and genetic stability in haematopoietic progenitors, and in the development of lymphoid and erythroid lineages. Total RNA from different mouse tissues (liver, bone marrow, brain) and cell types (embryonic fibroblasts - MEFs, and embryonic stem cells - ESCs) from wild type, Mysm1+/tm1a (heterozygous), and Mysm1tma1/tm1a (homozygous) mice was analyzed. Tissue and MEFs comparisons are between 3-4 animals per group; ESC comparisons are between three independently passaged samples of wild type, Mysm1+/tm1a, and Mysm1tma1/tm1aES-cells, all on C57BL/6 background. Full allele name: Mysm1tm1a(KOMP)WTSI . This Series includes the data from the tissues.
Project description:MYSM1 is a transcriptional regulator essential for HSC function and hematopoiesis. We established that p53 activation is a common mechanism mediating HSC dysfunction, MPP depletion, and lymphopenia in Mysm1-deficiency, however, the specific p53-induced effectors that trigger dysfunction in Mysm1-deficient HSPCs remain unknown. Here, we performed RNA-Seq of Lin-cKit+Sca1+CD150+ and CD150- HSPCs from Mysm1-/-Puma-/-, Mysm1-/-Puma+/-, Puma-/-, and wild-type mice; (Mysm1-/-Puma+/- phenocopies Mysm1-/-). We showed that Bbc3/PUMA is the primary non-redundant mediator of MPP depletion in Mysm1-deficiency and contributes to HSC dysfunction, whereas depletion of lymphoid-lineage cells involves PUMA-independent p53 activities. We also identified a broad downregulation of genes encoding protein components of the ribosome (RP-genes) and other regulators of translation in Mysm1-deficiency, and the downregulation persisted in Mysm1-/-Puma-/-.
Project description:Mouse meander tail (mea) mutations produce kinked tails and selective malformation of the cerebellum anterior compartment. The anterior cerebellum defects are cell autonomous with respect to granule cell precursors, but the molecular basis has not been known. Myb-like, SWIRM, and MPN domain containing protein 1 (MYSM1) is a chromatin-associated deubiquitinase that promotes gene expression by removing monoubiquitin from histone H2A, among other targets. Loss of MYSM1 function in mice or humans results in bone marrow failure with defective maturation of B cell lineages. Here we show that extant mea alleles have mutations in Mysm1 and cause both neurological and hematological phenotypes, as do new endonuclease-mediated mutations. Multimodal single-nucleus assays show Mysm1 effects on gene expression in several lineages and on the proportion of granule cell precursors by E14.5. Intriguingly, Mysm1 orthologs have been independently lost in several animal and fungal lineages, including yeast, flies, and nematodes. These results unite previously disconnected literature and demonstrate a requirement for MYSM1 activity in compartment-specific development in developing mammalian brain and suggest potential for compensatory pathways.
Project description:Stem cell differentiation and lineage specification depend on coordinated programs of gene expression, but our knowledge of the chromatin modifying factors regulating these events remains incomplete. Ubiquitination of histone H2A (H2A-K119u) is a common chromatin modification associated with gene silencing, and controlled by the ubiquitin-ligase polycomb repressor complex 1 (PRC1) and H2A-deubiquitinating enzymes (H2A-DUBs). The roles of H2A-DUBs in mammalian development, stem cells, and haematopoiesis have not been addressed. Here we characterized an H2A-DUB targeted mouse line Mysm1-tm1a/tm1a and demonstrated defects in bone marrow haematopoiesis, resulting in lymphopenia, anemia, and thrombocytosis. Development of lymphocytes was impaired from the earliest stages of their differentiation; and there was also a depletion of erythroid cells and a defect in erythroid progenitor function. These phenotypes were due to a cell-intrinsic requirement for Mysm1 in the bone marrow. Importantly, Mysm1-tm1a/tm1a haematopoietic stem cells were functionally impaired, and this was associated with elevated levels of reactive oxygen species, γH2AX DNA damage marker, and p53 protein in the haematopoietic progenitors. Overall these data establish a role for Mysm1 in the maintenance of bone marrow stem cell function, in the control of oxidative stress and genetic stability in haematopoietic progenitors, and in the development of lymphoid and erythroid lineages. Total RNA from different mouse tissues (liver, bone marrow, brain) and cell types (embryonic fibroblasts - MEFs, and embryonic stem cells - ESCs) from wild type, Mysm1+/tm1a (heterozygous), and Mysm1tma1/tm1a (homozygous) mice was analyzed. Tissue and MEFs comparisons are between 3-4 animals per group; ESC comparisons are between three independently passaged samples of wild type, Mysm1+/tm1a, and Mysm1tma1/tm1aES-cells, all on C57BL/6 background. Full allele name: Mysm1tm1a(KOMP)WTSI . This Series includes the data from the cells.