Saccharomyces cerevisiae
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA108227 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:MOTIVATION: Fanconi anemia (FA) is a chromosomal instability syndrome originated by inherited mutations that impair the Fanconi Anemia/Breast Cancer (FA/BRCA) pathway, which is committed to the repair of DNA interstrand cross-links (ICLs). The disease displays increased spontaneous chromosomal aberrations and hypersensitivity to agents that create DNA interstrand cross-links. In spite of DNA damage, FA/BRCA-deficient cells are able to progress throughout the cell cycle, probably due to the activity of alternative DNA repair pathways, or due to defects in the checkpoints that monitor DNA integrity. RESULTS: We propose a Boolean network model of the FA/BRCA pathway, Checkpoint proteins and some alternative DNA repair pathways. To our knowledge, this is the largest network model incorporating a DNA repair pathway. Our model is able to simulate the ICL repair process mediated by the FA/BRCA pathway, the activation of Checkpoint proteins observed by recurrent DNA damage, as well as the repair of DNA double-strand breaks and DNA adducts. We generated a series of simulations for mutants, some of which have never been reported and thus constitute predictions about the function of the FA/BRCA pathway. Finally, our model suggests alternative DNA repair pathways that become active whenever the FA/BRCA pathway is defective.
| 1778 | Cell Collective
Project description:Oxidative DNA damage is likely to be involved in the etiology of cancer and is thought to accelerate tumorigenesis via increased mutation rates. However, the majority of malignant cells acquire a specific type of genomic instability characterized by large-scale genomic rearrangements, defined as chromosomal instability (CIN). The molecular mechanisms underlying CIN are largely unknown. We utilized Saccharomyces cerevisiae as a model system to delineate the relationship between genotoxic stress and CIN. It was found that elevated levels of chronic, unrepaired oxidative DNA damage cause chromosomal aberrations at remarkably high frequencies under both selective and non-selective growth conditions. In this system, exceeding the cellular capacity to appropriately manage oxidative DNA damage results in a “gain of CIN” phenotype and leads to profound karyotypic diversification. These results illustrate a novel mechanism for genome destabilization, which is likely to be relevant to human carcinogenesis. Keywords: CGH-array
2008-02-10 | GSE10152 | GEO
Project description:Genome instability is a condition characterized by the accumulation of various genetic alterations and is a hallmark of cancer cells. To uncover new genes and cellular pathways controlling the levels of endogenous DNA damage and affecting genome integrity, we exploited a Synthetic Genetic Array (SGA)-based screen in yeast. Among the positive genes, we identified VID22, a gene previously reported to be involved in DNA double-strand break repair. We found that vid22Δ cells exhibit chronic DNA damage response activation, show increased levels of increased endogenous DNA damage and accumulate DNA aberrations in sequences displaying high probabilities of forming G-quadruplexes (G4-DNA). If not resolved, these non-canonical DNA secondary structures can block the progression of both DNA and RNA polymerases and correlate with chromosome fragile sites. We show that Vid22 in vitro and in vivo binds directly to and protects DNA at G4-containing regions both in vitro and in vivo. In particular, loss of VID22 causes an increase in gross chromosomal rearrangement (GCR) events dependent on G-quadruplex forming sequences. We also demonstrate that the absence of Vid22 causes defects in the correct maintenance of G4-DNA rich elements, such as telomeres and mtDNA, and hypersensitivity to the G4-stabilizing ligand TMPyP4. We thus propose that Vid22 is directly involved in genome integrity maintenance as a novel regulator of G4 metabolism.
2021-11-08 | GSE174688 | GEO
Project description:Mastl is commonly overexpressed in cancer, appearing as an alternative therapeutic anticancer target. Loss of Mastl induces multiple chromosomal mitotic errors that lead to the accumulation of micronuclei and multilobulated cells with polyploidy. Our detailed analyses display that loss of Mastl quickly lead to chromosomes breakage and abnormalities impairing correct segregation. Phosphoproteomic data of mouse embryonic fibroblasts revealed defects in kinetochores, perichromosomes, and centrosomes but also on RNA binding proteins and double strand DNA damage repair.In our study, Rad51ap1, a well-known homologous recombination regulator, appeared to be effectively phosphorylated by Nek2 and CDK1, but also efficiently depshosphorylated by PP2A/B55. Taken together, these results suggest that Mastl loss induces a multitude of alteration even in noncancerous cells that lead to the disruption of DNA damage repair triggering chromosomes breakage and in consequence, creates an accumulative disequilibrium in the phosphoproteome.
2020-10-15 | PXD019297 | JPOST Repository
Project description:The Mre11 complex (Mre11, Rad50, and Nbs1) and Chk2 have been implicated in the DNA damage response, an inducible process required for the suppression of malignancy. The Mre11 complex is predominantly required for repair and checkpoint activation in S phase, while Chk2 governs apoptosis. We examined the relationship between the Mre11 complex and Chk2 in the DNA damage response via the establishment of Nbs1âB/âB Chk2-/- and Mre11ATLD1/ATLD1 Chk2-/- mice. Chk2 deficiency did not modify the checkpoint defects or chromosomal instability of Mre11 complex mutants; however, the double mutant mice exhibited synergistic defects in DNA damage-induced p53 regulation and apoptosis. Nbs1âB/âB Chk2-/- and Mre11ATLD1/ATLD1 Chk2-/- mice were also predisposed to tumors. In contrast, DNA-PKcs deficient mice, in which G1-specific chromosome breaks are present, did not exhibit synergy with Chk2-/- mutants. These data suggest that Chk2 suppresses the oncogenic potential of DNA damage arising during S and G2 phases of the cell cycle. Experiment Overall Design: Thymocytes from Wild type (Wt), Atm-/- and Chk2-/- mice were exposed to mock 5 Gy radiation (IR). The RNA was harvested 8 hours post treatment.
2008-06-20 | E-GEOD-11436 | biostudies-arrayexpress
Project description:Targetted metabolomics in U2OS PRDX1 WT and PRDX1-/- While cellular metabolism impacts the DNA damage response, a systematic understanding of the metabolic requirements that are crucial for DNA damage repair has yet to be achieved. Here, we investigate the metabolic enzymes and processes that are essential when cells are exposed to DNA damage. By integrating functional genomics with chromatin proteomics and metabolomics, we provide a detailed description of the interplay between cellular metabolism and the DNA damage response. Subsequent analysis identified Peroxiredoxin 1, PRDX1, as fundamental for DNA damage repair. During the DNA damage response, PRDX1 translocates to the nucleus where it is required to reduce DNA damage-induced nuclear reactive oxygen species levels. Moreover, PRDX1 controls aspartate availability, which is required for the DNA damage repair-induced upregulation of de novo nucleotide synthesis. Loss of PRDX1 leads to an impairment in the clearance of γΗ2ΑΧ nuclear foci, accumulation of replicative stress and cell proliferation defects, thus revealing a crucial role for PRDX1 as a DNA damage surveillance factor.
2022-07-19 | ST002234 | MetabolomicsWorkbench
Project description:A-type lamins, the key structural components of the nucleus, are emerging as regulators in the maintenance of nuclear architecture and genome organization. Extensive research for the last two decades has enormously contributed in understanding the roles of lamins in various signaling mechanisms which frequently go awry in neoplasias. It is interesting to know that alteration in lamin A/C expression and distribution drives tumorigenesis thus modifying its expression can be a potent therapeutic approach. One of the important signatures of a cancer cell is its inability to repair DNA damage which befalls due to a number of genomic defects that transform the cells to be sensitive to chemotherapeutic agents. Also, the errors in DNA repair mechanism are accompanied by high replication rate. This genomic and chromosomal instability is the most conventional feature found in cases of high grade ovarian serous carcinoma. Here, we report elevated levels of lamins in OVCAR3 cells (High grade ovarian serous carcinoma cell line) with respect to IOSE (Immortalised ovarian surface epithelial cells) and the altered damage repair machineries in both the cell lines. We have analysed the changes in global gene expression in sequel to DNA damage induced by etoposide in lamin A upregulated ovarian carcinoma background and reported a number of differentially expressed genes associated with pathways conferring cellular proliferation and chemoresistance. We highlight new avenues unravelling the role of an upregulated lamin A in confronting chemically induced genomic instability in the context of ovarian cancer.
2022-08-23 | GSE211529 | GEO
Project description:Ataxia-telangiectasia (A-T) is a disease characterized by genomic instability and severe neurodegeneration. It is caused by mutation in Ataxia-telangiectasia mutated gene (ATM) which encodes ATM, a key player in DNA double-strand break (DSB) repair. While many major symptoms of A-T (including hypersensitivity to ionizing radiation) are readily explained by its deficiency in repair of DSBs, the causes for the devastating cerebellar degeneration are still elusive. Here we report that in A-T, persistent unrepaired DNA damage signals from the nucleus to mitochondria (NM signaling) causing mitochondrial dysfunction leading to neurodegeneration. We find that depletion of NAD+ in A-T across species is likely due to persistent PARylation as inhibition of PARP1 restores NAD+levels.. NAD+ depletion affects the NAD+/SIRT1-PGC1α axis causing accumulation of damaged mitochondria through inhibition of mitophagy. Restoration of NAD+/SIRT1 activity through PARP1 inhibition, NAD+ supplementation or SIRT1 activation rescued the pathological and behavioral defects in A-T, suggesting a conserved role of the NAD+/SIRT1 pathway in inhibiting disease pathology. Notably, increasing the NAD+ levels extends lifespan and rescues A-T-specific behavioral defects in both C. elegans and mouse models of A-T. This is through induction of PINK1-DCT1-regulated mitophagy and DNA-PKcs-associated NHEJ DNA repair. Our results underscore the unified role of SIRT1 (Sir2.1) in mitochondrial health and highlight how Sir2.1 not only regulates mitochondrial biogenesis, but also induces PINK1-DCT1-dependent mitophagy. Our data support a model where by the two major theories on aging, DNA damage accumulation and mitochondrial dysfunction, conspire to promote neurodegeneration in A-T animal models and suggest that therapeutic interventions are possible in A-T and other untreatable DNA repair-deficient disorders.
2018-06-25 | PXD003380 | Pride
Project description:The large majority of oxidative lesions occurring in the G1 phase of the cell cycle are repaired by base excision repair (BER) rather than mismatch repair (MMR) to avoid long resections that can lead to genomic instability and cell death. However, how cells choose BER over MMR is not yet understood. Here, we show that, during G1, D-type cyclins are recruited to sites of oxidative DNA damage in a PCNA- and p21-dependent manner. In turn, in a manner that is independent on CDK4/6 activity, D-type cyclins stabilize p21, which competes through its PCNA-interacting protein (PIP) box with MMR components for their binding to PCNA. This reduces MMR activity while allowing BER. At the G1/S transition, the AMBRA1-dependent degradation of D-type cyclins renders p21 susceptible to proteolysis via SKP2 and CDT2. These timely degradation events allow the proper binding of MMR proteins to PCNA enabling the repair of DNA replication errors. Thus, the expression of D-type cyclins limit MMR in G1, whereas their degradation is necessary for proper MMR function in S. Defects in these two regulatory mechanisms promote genome instability. The mass spectrometry raw files correspond to the affinity purifications of proximity labeled (turbo-ID) PCNA and CCND1 under various conditions.
2023-01-03 | MSV000091006 | MassIVE
Project description:The Mre11 complex (Mre11, Rad50, and Nbs1) and Chk2 have been implicated in the DNA damage response, an inducible process required for the suppression of malignancy. The Mre11 complex is predominantly required for repair and checkpoint activation in S phase, while Chk2 governs apoptosis. We examined the relationship between the Mre11 complex and Chk2 in the DNA damage response via the establishment of Nbs1∆B/∆B Chk2-/- and Mre11ATLD1/ATLD1 Chk2-/- mice. Chk2 deficiency did not modify the checkpoint defects or chromosomal instability of Mre11 complex mutants; however, the double mutant mice exhibited synergistic defects in DNA damage-induced p53 regulation and apoptosis. Nbs1∆B/∆B Chk2-/- and Mre11ATLD1/ATLD1 Chk2-/- mice were also predisposed to tumors. In contrast, DNA-PKcs deficient mice, in which G1-specific chromosome breaks are present, did not exhibit synergy with Chk2-/- mutants. These data suggest that Chk2 suppresses the oncogenic potential of DNA damage arising during S and G2 phases of the cell cycle. Keywords: Global gene expression analysis, response to radiation, Nbs1∆B/∆B Chk2-/- and Mre11ATLD1/ATLD1 Chk2-/- mutant mice
2008-05-15 | GSE11436 | GEO