scholarly journals Asymmetric chromosome segregation and cell division in DNA damage-induced bacterial filaments

2020 ◽  
Vol 31 (26) ◽  
pp. 2920-2931
Author(s):  
Suchitha Raghunathan ◽  
Afroze Chimthanawala ◽  
Sandeep Krishna ◽  
Anthony G. Vecchiarelli ◽  
Anjana Badrinarayanan
Keyword(s):  
Dna Damage ◽  
Cell Division ◽  
Dna Damage Response ◽  
Chromosome Segregation ◽  
Asymmetric Division ◽  
Model Systems ◽  
Wild Type ◽  
Central Function ◽  
Damage Response ◽  
Bacterial Model

The DNA damage response and cell division checkpoints have been well studied in several bacterial model systems, but how cells exit such a checkpoint to restart wild-type growth is unclear. This study highlights a central function for asymmetric division in mediating cellular recovery from DNA damage.

scholarly journals Comparisons Between DT40 Wild Type and DT40-Cre1 Cells as Suitable Model Systems for Studying the DNA Damage Response

Cell Cycle ◽  
2007 ◽  
Vol 6 (18) ◽  
pp. 2310-2313 ◽  
Author(s):  
Ronan T. Bree ◽  
Xian-Yang Lai ◽  
Lynn E. Canavan ◽  
Noel F. Lowndes
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Model Systems ◽  
Suitable Model ◽  
Wild Type ◽  
Damage Response

scholarly journals Asymmetric chromosome segregation and cell division in DNA damage-induced bacterial filaments

2020 ◽  
Author(s):  
Suchitha Raghunathan ◽  
Afroze Chimthanawala ◽  
Sandeep Krishna ◽  
Anthony G. Vecchiarelli ◽  
Anjana Badrinarayanan
Keyword(s):  
Dna Damage ◽  
Cell Division ◽  
Cell Size ◽  
Cell Cycle Progression ◽  
Growth Dynamics ◽  
Asymmetric Division ◽  
Wild Type ◽  
Central Function ◽  
Repair Mechanisms ◽  
Type Size

AbstractFaithful propagation of life requires coordination of DNA replication and segregation with cell growth and division. In bacteria, this results in cell size homeostasis and periodicity in replication and division. The situation is perturbed under stress such as DNA damage, which induces filamentation as cell cycle progression is blocked to allow for repair. Mechanisms that release this morphological state for re-entry into wild type growth are unclear. Here we show that damage recovery is mediated via asymmetric division of Escherichia coli filaments, producing short daughter cells with wild type size and growth dynamics. Division restoration at this polar site is governed by coordinated action of divisome positioning by the Min system and modulation of division licensing by the terminus region of the chromosome, with MatP playing a central role in this process. Collectively, our study highlights a key role for concurrency between chromosome (and specifically terminus) segregation and cell division in daughter cell size maintenance during filamentous divisions and suggests a central function for asymmetric division in mediating cellular recovery from a stressed state.

scholarly journals Distinct Functions in Regulation of Meiotic Crossovers for DNA Damage Response Clamp Loader Rad24(Rad17) and Mec1(ATR) Kinase

Genetics ◽  
2019 ◽  
Vol 213 (4) ◽  
pp. 1255-1269 ◽  
Author(s):  
Miki Shinohara ◽  
Douglas K. Bishop ◽  
Akira Shinohara
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Chromosome Segregation ◽  
Meiotic Chromosome ◽  
Clamp Loader ◽  
Link Type ◽  
Distinct Mechanism ◽  
Damage Response ◽  
Specific Manner ◽  
Atr Kinase

The number and distribution of meiotic crossovers (COs) are highly regulated, reflecting the requirement for COs during the first round of meiotic chromosome segregation. CO control includes CO assurance and CO interference, which promote at least one CO per chromosome bivalent and evenly-spaced COs, respectively. Previous studies revealed a role for the DNA damage response (DDR) clamp and the clamp loader in CO formation by promoting interfering COs and interhomolog recombination, and also by suppressing ectopic recombination. In this study, we use classical tetrad analysis of Saccharomyces cerevisiae to show that a mutant defective in RAD24, which encodes the DDR clamp loader (RAD17 in other organisms), displayed reduced CO frequencies on two shorter chromosomes (III and V), but not on a long chromosome (chromosome VII). The residual COs in the rad24 mutant do not show interference. In contrast to rad24, mutants defective in the ATR kinase homolog Mec1, including a mec1 null and a mec1 kinase-dead mutant, show slight or few defects in CO frequency. On the other hand, mec1 COs show defects in interference, similar to the rad24 mutant. Our results support a model in which the DDR clamp and clamp-loader proteins promote interfering COs by recruiting pro-CO Zip, Mer, and Msh proteins to recombination sites, while the Mec1 kinase regulates CO distribution by a distinct mechanism. Moreover, CO formation and its control are implemented in a chromosome-specific manner, which may reflect a role for chromosome size in regulation.

scholarly journals Down-regulation of Wild-type p53-induced Phosphatase 1 (Wip1) Plays a Critical Role in Regulating Several p53-dependent Functions in Premature Senescent Tumor Cells

2013 ◽  
Vol 288 (23) ◽  
pp. 16212-16224 ◽  
Author(s):  
Elvira Crescenzi ◽  
Zelinda Raia ◽  
Francesco Pacifico ◽  
Stefano Mellone ◽  
Fortunato Moscato ◽  
...  
Keyword(s):  
Dna Damage ◽  
Tumor Cells ◽  
Dna Damage Response ◽  
Critical Role ◽  
Wild Type ◽  
Down Regulation ◽  
Senescent Phenotype ◽  
Response To Chemotherapy ◽  
Damage Response ◽  
Wild Type P53

Premature or drug-induced senescence is a major cellular response to chemotherapy in solid tumors. The senescent phenotype develops slowly and is associated with chronic DNA damage response. We found that expression of wild-type p53-induced phosphatase 1 (Wip1) is markedly down-regulated during persistent DNA damage and after drug release during the acquisition of the senescent phenotype in carcinoma cells. We demonstrate that down-regulation of Wip1 is required for maintenance of permanent G2 arrest. In fact, we show that forced expression of Wip1 in premature senescent tumor cells induces inappropriate re-initiation of mitosis, uncontrolled polyploid progression, and cell death by mitotic failure. Most of the effects of Wip1 may be attributed to its ability to dephosphorylate p53 at Ser15 and to inhibit DNA damage response. However, we also uncover a regulatory pathway whereby suppression of p53 Ser15 phosphorylation is associated with enhanced phosphorylation at Ser46, increased p53 protein levels, and induction of Noxa expression. On the whole, our data indicate that down-regulation of Wip1 expression during premature senescence plays a pivotal role in regulating several p53-dependent aspects of the senescent phenotype.

Replication Associated Stress in the Fetal Stem Cell Pool of FA Mice Can be Rescued By Pharmacologic Inhibition of Constitutively Activated P38 MAPK

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2411-2411
Author(s):  
Youngme Yoon ◽  
Ashley N. Kamimae-Lanning ◽  
Kelsie Storm ◽  
Natalya A Goloviznina ◽  
Peter Kurre
Keyword(s):  
Dna Damage ◽  
Stress Response ◽  
P38 Mapk ◽  
Dna Damage Response ◽  
Colony Formation ◽  
Model Systems ◽  
Donor Chimerism ◽  
Damage Response ◽  
Physiologic Role

Abstract Fanconi Anemia (FA) is a rare, recessively heritable disorder with prominent failure of hematopoiesis. The physiologic role of FA proteins has not been fully resolved to date. While several existing model systems delineate its role in DNA damage response caused by alkylating agents, aldehydes, and inflammatory cytokines, all rely on experimental induction. We previously demonstrated the in utero onset of hematopoietic failure in mice with genetic disruption of Fancc. Herein, we found significant deficits in the fetal liver (FL) hematopoietic stem and progenitor cell (HSPC) pool in Fancd2 mice. Both AA4.1+ Sca-1+ Lin- expressing progenitors (ASL) and CD48- CD150+ Lin- Sca-1+ (SLAM) cells were decreased in frequency in Fancd2-/- versus WT FL. Similarly, we observed a significant decrease in progenitor colony formation and deficits in primary and secondary transplantation among Fancd2-/- FL compared to WT. Fancd2-/- FL cells were characteristically sensitive to mitomycin C and had significantly fewer SLAM cells in the G0 phase of cell cycle and elevated p21 expression, indicating canonical P53 activation. Consistent with prior reports by other groups on embryonic stem cells and our own Fancc-/- FL studies, we found neither exaggerated frequency of apoptotic cells, nor transcriptional induction of Puma or Noxa. We hypothesized that the observed deficits in developmental HSPC pool expansion reflect replication-associated stress. At the transcriptional level, we found activation of the DNA damage response via Rad51 and Prkdc, corroborated by immunofluorescent imaging of Rad51 foci as well as comet assays in FL cells. Next, we tested P38 MAPK as a stress response previously found to confer repopulation deficits in postnatal BM failure among Fancc and Fanca mice; here, our experiments revealed baseline (unprovoked) activation of phospho-p38 and rescue of Fancd2-/- progenitor colony formation using a pharmacological inhibitor, SB203580. Results were further strengthened by transplantation, revealing increased Fancd2-/- donor chimerism after in vivo administration of SB203580. The gains in donor chimerism persisted even after cessation of drug administration. These results suggest that replication-associated stress in the rapidly cycling fetal Fancd2-/- HSPC pool evokes a cellular stress response that constrains physiological expansion. Our work emphasizes the prenatal onset of hematopoietic failure and reveals pharmacological rescue by inhibition of constitutively active P38 MAPK. Furthermore, FA fetal hematopoiesis is an original model of unprovoked hematopoietic failure that allows the study of physiologic role of FA proteins in HSPC. Disclosures No relevant conflicts of interest to declare.

scholarly journals The dual role of the RETINOBLASTOMA-RELATED protein in the DNA damage response is spatio-temporally coordinated by the interaction with LXCXE-containing proteins.

2021 ◽  
Author(s):  
Jorge Zamora-Zaragoza ◽  
Katinka Klap ◽  
Renze Heidstra ◽  
Wenkun Zhou ◽  
Ben Scheres
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Dna Repair ◽  
Cell Division ◽  
Dna Damage Response ◽  
Growth Arrest ◽  
Focus Formation ◽  
Damage Response ◽  
Nuclear Foci ◽  
Lxcxe Motif

Living organisms face threats to genome integrity caused by environmental challenges or metabolic errors in proliferating cells. To avoid the spread of mutations, cell division is temporarily arrested while repair mechanisms deal with DNA lesions. Afterwards, cells either resume division or respond to unsuccessful repair by withdrawing from the cell cycle and undergoing cell death. How the success rate of DNA repair connects to the execution of cell death remains incompletely known, particularly in plants. Here we provide evidence that the Arabidopsis thaliana RETINOBLASTOMA-RELATED1 (RBR) protein, shown to play structural and transcriptional functions in the DNA damage response (DDR), coordinates these processes in time by successive interactions through its B-pocket sub-domain. Upon DNA damage induction, RBR forms nuclear foci; but the N849F substitution in the B-pocket, which specifically disrupts binding to LXCXE motif-containing proteins, abolishes RBR focus formation and leads to growth arrest. After RBR focus formation, the stress-responsive gene NAC044 arrests cell division. As RBR is released from nuclear foci, it can be bound by the conserved LXCXE motif in NAC044. RBR-mediated cell survival is inhibited by the interaction with NAC044. Disruption of NAC044-RBR interaction impairs the cell death response but is less important for NAC044 mediated growth arrest. Noteworthy, unlike many RBR interactors, NAC044 binds to RBR independent of RBR phosphorylation. Our findings suggest that the availability of the RBR B-pocket to interact with LXCXE-containing proteins couples the structural DNA repair functions and the transcriptional functions of RBR in the cell death program.

scholarly journals Involvement of Serine / Threonine protein kinases in DNA damage response and cell division in bacteria

2021 ◽  
pp. 103883
Author(s):  
Yogendra S. Rajpurohit ◽  
Dhirendra Kumar Sharma ◽  
Hari S. Misra
Keyword(s):  
Dna Damage ◽  
Cell Division ◽  
Protein Kinases ◽  
Dna Damage Response ◽  
Damage Response

scholarly journals Generation of inducible SMARCAL1 knock-down iPSC to model severe Schimke immune-osseous dysplasia reveals a link between replication stress and altered expression of master differentiation genes

2019 ◽  
Author(s):  
Giusj Monia Pugliese ◽  
Federico Salaris ◽  
Valentina Palermo ◽  
Veronica Marabitti ◽  
Nicolò Morina ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Severe Form ◽  
Model Systems ◽  
Altered Expression ◽  
Osseous Dysplasia ◽  
Human Ipscs ◽  
Damage Response ◽  
Transcription Interference

ABSTRACTThe Schimke immuno-osseous dysplasia is an autosomal recessive genetic osteochondrodysplasia characterized by dysmorphism, spondyloepiphyseal dysplasia, nephrotic syndrome and frequently T cell immunodeficiency. Several hypotheses have been proposed to explain pathophysiology of the disease, however, the mechanism by which SMARCAL1 mutations cause the syndrome is elusive. Indeed, animal models of the disease are absent or useless to provide insight into the disease mechanism, since they do not recapitulate the phenotype. We generated a conditional knockdown model of SMARCAL1 in iPSCs to mimic conditions of cells with severe form the disease. Here, we characterize this model for the presence of phenotype linked to the replication caretaker role of SMARCAL1 using multiple cellular endpoints. Our data show that conditional knockdown of SMARCAL1 in human iPSCs induces replication-dependent and chronic accumulation of DNA damage triggering the DNA damage response. Furthermore, they indicate that accumulation of DNA damage and activation of the DNA damage response correlates with increased levels of R-loops and replication-transcription interference. Finally, we provide data showing that, in SMARCAL1-deficient iPSCs, DNA damage response can be maintained active also after differentiation, possibly contributing to the observed altered expression of a subset of germ layer-specific master genes. In conclusion, our conditional SMARCAL1 iPSCs may represent a powerful model where studying pathogenetic mechanisms of severe Schimke immuno-osseous dysplasia, thus overcoming the reported inability of different model systems to recapitulate the disease.

scholarly journals DNA Damage-Response Pathway in Lymphoma Determines Interactions with Macrophages By Altered PD-L1 Expression and Exosome Formation

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 275-275
Author(s):  
Daniela Vorholt ◽  
Elena Izquierdo-Alvarez ◽  
Benedict Sackey ◽  
Jan Schmitz ◽  
Nadine Nickel ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Research Funding ◽  
Therapeutic Response ◽  
Wild Type ◽  
Lymphoma Cells ◽  
Damage Response ◽  
Dna Damage Response Pathway ◽  
Support Research

Abstract The tumor microenvironment is characterized by multiple interactions of transformed malignant cells with non-transformed stroma or immune cells. Particularly macrophages play a pivotal role in this network determining disease progression and therapeutic response. In previous work we could show that macrophages are an essential mediator of therapeutic response in the synergistic response to the administration of the chemoimmunotherapy. The combination treatment strongly increases tumor clearance by repolarization of tumor-associated macrophages from a suppressive to an activated phenotypic state. Here, se analyzed the functional implications of the DNA damage response pathway for the generation of the ASAP and synergy in chemoimmunotherapy. We attempted to disrupt DNA damage response pathway in lymphoma cells generated from the hMB humanized Double-Hit-Lymphoma model by knock-down of key elements like ATM, DNA-PK or p53. We could prevent the formation of the stimulatory cytokine release effect on macrophage phagocytic capacity. Here, p53 status displays a key regulatory role on macrophage mediated malignant cell depletion. TP53 activation via Nutlin-3A treatment of lymphoma cell enhances ADCP in in p53 wild-type cells, while not displaying enhancement in p53-deficient lymphoma cells. Addressing the treatment in vivo using the hMB model for modeling of Double-Hit Lymphoma bearing mice we could demonstrate diminished ASAP and ADCP for p53-deficient lymphoma treated with cyclophosphamide in vivo. Using primary human CLL patient cells comparing both wild-type and p53-deficient status, the p53-deficient CLL cells failed to induce the stimulatory, cytokine-mediated effect on macrophage phagocytosis in response to combination treatment as seen with the p53 proficient CLL cells. Using a CLL mouse model by treating Eµ-TCL1/p53wt/wt as well as Eµ-TCL1p53-/- mice we could show that low-dose cyclophosphamide treated Eµ-TCL1p53-/- mice failed to induce an antibody mediated stimulatory effect on macrophage phagocytosis capacity as seen with Eµ-TCL1/p53wt/wt mice. A similar effect was seen for primary multiple myeloma cells in response to daratumumab displaying significantly less ADCP of p53-deficient multiple myeloma cells. As for the mechanism of p53-defined interaction within the tumor microenvironment we subjected p53-wild-type and p53-deficient lymphoma cells for proteomic analysis. Here we could identify a significantly deregulated protein expression profile for exosome release in p53 deficient lymphoma cells. Verifying this finding by assessing size and frequency exosomes released by respective cell populations we reveal profound changes induced by p53 loss. Furthermore we could identify up-regulation of PD-L1 in p53-deficient cells. Blocking this checkpoint in the ADCP assay could significantly restore phagocytic capacity of macrophages and overall therapeutic response. In this work, we indicate that p53 functional status determines phagocytic function and therapeutic response to monoclonal antibodies. We can verify this finding in independent models in vitro and in vivo as in primary CLL and myeloma patient cells. We furthermore identify altered exosome profiles and checkpoint inhibitor expression in lymphoma cells as underlying mechanism of macrophage modulation. Finally our ongoing research offers possibility to reveal and tailor new combinatorial treatment approaches for chemo-refractory patients. Disclosures Wendtner: Genetech: Consultancy, Honoraria, Other: travel support, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: travel support, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: travel support, Research Funding; Abbvie: Consultancy, Honoraria, Other: travel support, Research Funding; MorphoSys: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; Roche: Consultancy, Honoraria, Other: travel support, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding. Hallek:Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding. Pallasch:Gilead: Research Funding.

Sign in / Sign up

Export Citation Format

Share Document