Similar Datasets
Project description:Chromatin regulates spatiotemporal gene expression during neurodevelopment, but it also mediates DNA damage repair crucial to proliferating neural progenitor cells (NPCs). Here, we uncover molecularly dissociable roles for nucleosome remodeler INO80 in chromatin-mediated transcriptome and genome maintenance in corticogenesis. We find that conditional Ino80 deletion from cortical NPCs impairs DNA double-strand break repair, triggering p53 activation, robust apoptosis, and microcephaly, whereas co-deletion of Trp53 with Ino80 leads to remarkable reversal of these phenotypes. Using an in vivo DNA repair assay, we find that Ino80 is selectively required for homologous recombination (HR) DNA repair, which is mechanistically distinct from INO80 function in YY1-associated transcription. Unexpectedly, sensitivity to loss of INO80-mediated HR is dependent on the mode of NPC division: Ino80 deletion causes extensive DNA damage and apoptosis in symmetric NPC-NPC divisions, but not in asymmetric neurogenic divisions. Thus, distinct modes of NPC division have divergent requirements for Ino80-dependent HR DNA repair.
2020-06-23 | GSE153061 | GEO
Project description:Chromatin regulates spatiotemporal gene expression during neurodevelopment, but it also mediates DNA damage repair crucial to proliferating neural progenitor cells (NPCs). Here, we uncover molecularly dissociable roles for nucleosome remodeler INO80 in chromatin-mediated transcriptome and genome maintenance in corticogenesis. We find that conditional Ino80 deletion from cortical NPCs impairs DNA double-strand break repair, triggering p53 activation, robust apoptosis, and microcephaly, whereas co-deletion of Trp53 with Ino80 leads to remarkable reversal of these phenotypes. Using an in vivo DNA repair assay, we find that Ino80 is selectively required for homologous recombination (HR) DNA repair, which is mechanistically distinct from INO80 function in YY1-associated transcription. Unexpectedly, sensitivity to loss of INO80-mediated HR is dependent on the mode of NPC division: Ino80 deletion causes extensive DNA damage and apoptosis in symmetric NPC-NPC divisions, but not in asymmetric neurogenic divisions. Thus, distinct modes of NPC division have divergent requirements for Ino80-dependent HR DNA repair.
2020-06-25 | GSE133799 | GEO
Project description:Symmetric neural progenitor divisions require chromatin-mediated homologous recombination DNA repair by Ino80
| PRJNA641343 | ENA
Project description:Symmetric neural progenitor divisions require chromatin-mediated homologous recombination DNA repair by Ino80 [ATAC-seq]
| PRJNA641347 | ENA
Project description:Symmetric neural progenitor divisions require chromatin-mediated homologous recombination DNA repair by Ino80 [RNA-seq]
| PRJNA552556 | ENA
Project description:Maintaining genomic stability is a prerequisite for proliferating NPCs to ensure genetic fidelity. Though histone arginine methylation has been shown to play important roles in safeguarding genomic stability, the underlying mechanism during brain development is not fully understood. Protein arginine N-methyltransferase 5 (PRMT5) is a type II protein arginine methyltransferase that plays a role in transcriptional regulation. Here, we identify PRMT5 as a key regulator of DNA repair in response to double-strand breaks (DSBs) during NPC proliferation. Prmt5F/F; Emx1-Cre (cKO-Emx1) mice show a distinctive microcephaly phenotype, with partial loss of the dorsal medial cerebral cortex and complete loss of the corpus callosum and hippocampus. This phenotype is resulted from DSBs accumulation in the medial dorsal cortex followed by cell apoptosis. Both RNA sequencing and in vitro DNA repair analyses reveal that PRMT5 is required for DNA homologous recombination (HR) repair. PRMT5 specifically catalyzes H3R2me2s in proliferating NPCs in the developing mouse brain to enhance HR-related gene expression during DNA repair. Finally, overexpression of BRCA1 significantly rescues DSBs accumulation and cell apoptosis in PRMT5-deficient NSCs. Taken together, our results show that PRMT5 maintains genomic stability by regulating histone arginine methylation in proliferating NPCs.
| S-EPMC10923982 | biostudies-literature
Project description:DNA damage repair is crucial for the maintenance of genome integrity and cancer suppression. We found that loss of the mouse transcription factor YY1 resulted in polyploidy and chromatid aberrations, which are signatures of defects in homologous recombination. Further biochemical analyses identified a YY1 complex comprising components of the evolutionarily conserved INO80 chromatin-remodeling complex. Notably, RNA interference-mediated knockdown of YY1 and INO80 increased cellular sensitivity toward DNA-damaging agents. Functional assays revealed that both YY1 and INO80 are essential in homologous recombination-based DNA repair (HRR), which was further supported by the finding that YY1 preferentially bound a recombination-intermediate structure in vitro. Collectively, these observations reveal a link between YY1 and INO80 and roles for both in HRR, providing new insight into mechanisms that control the cellular response to genotoxic stress.
| S-EPMC2754171 | biostudies-literature
Project description:We characterized the in vivo importance of the homologous recombination factor RAD54 for the developing mouse brain cortex in normal conditions or after ionizing radiation exposure. Contrary to numerous homologous recombination genes, Rad54 disruption did not impact the cortical development without exogenous stress, but it dramatically enhanced the radiation sensitivity of neural stem and progenitor cells. This resulted in the death of all cells irradiated during S or G2, whereas the viability of cells irradiated in G1 or G0 was not affected by Rad54 disruption. Apoptosis occurred after long arrests at intra-S and G2/M checkpoints. This concerned every type of neural stem and progenitor cells, showing that the importance of Rad54 for radiation response was linked to the cell cycle phase at the time of irradiation and not to the differentiation state. In the developing brain, RAD54-dependent homologous recombination appeared absolutely required for the repair of damages induced by ionizing radiation during S and G2 phases, but not for the repair of endogenous damages in normal conditions. Altogether our data support the existence of RAD54-dependent and -independent homologous recombination pathways.
| S-EPMC3362579 | biostudies-other
Project description:The mammalian INO80 remodelling complex facilitates homologous recombination (HR), but the mechanism by which it does this is unclear. Budding yeast INO80 can remove H2A.Z/H2B dimers from chromatin and replace them with H2A/H2B dimers. H2A.Z is actively incorporated at sites of damage in mammalian cells, raising the possibility that H2A.Z may need to be subsequently removed for resolution of repair. Here, we show that H2A.Z in human cells is indeed rapidly removed from chromatin flanking DNA damage by INO80. We also report that the histone chaperone ANP32E, which is implicated in removing H2AZ from chromatin, similarly promotes HR and appears to work on the same pathway as INO80 in these assays. Importantly, we demonstrate that the HR defect in cells depleted of INO80 or ANP32E can be rescued by H2A.Z co-depletion, suggesting that H2A.Z removal from chromatin is the primary function of INO80 and ANP32E in promoting homologous recombination.
| S-EPMC4552491 | biostudies-literature
Project description:Large-scale genomic studies have shown that half of epithelial ovarian cancers (EOCs) have alterations in genes regulating homologous recombination (HR) repair. Loss of HR accounts for the genomic instability of EOCs and for their cellular hyper-dependence on alternative poly-ADP ribose polymerase (PARP)-mediated DNA repair mechanisms. Previous studies have implicated the DNA polymerase ? (Pol? also known as POLQ, encoded by POLQ) in a pathway required for the repair of DNA double-strand breaks, referred to as the error-prone microhomology-mediated end-joining (MMEJ) pathway. Whether Pol? interacts with canonical DNA repair pathways to prevent genomic instability remains unknown. Here we report an inverse correlation between HR activity and Pol? expression in EOCs. Knockdown of Pol? in HR-proficient cells upregulates HR activity and RAD51 nucleofilament assembly, while knockdown of Pol? in HR-deficient EOCs enhances cell death. Consistent with these results, genetic inactivation of an HR gene (Fancd2) and Polq in mice results in embryonic lethality. Moreover, Pol? contains RAD51 binding motifs and it blocks RAD51-mediated recombination. Our results reveal a synthetic lethal relationship between the HR pathway and Pol?-mediated repair in EOCs, and identify Pol? as a novel druggable target for cancer therapy.
| S-EPMC4415602 | biostudies-literature