The Anticancer Ruthenium Complex KP1019 Induces DNA Damage, Leading to Cell Cycle Delay and Cell Death in Saccharomyces cerevisiae

2012 ◽  
Vol 83 (1) ◽  
pp. 225-234 ◽  
Author(s):  
Shannon K. Stevens ◽  
Amy P. Strehle ◽  
Rebecca L. Miller ◽  
Sarah H. Gammons ◽  
Kyle J. Hoffman ◽  
...  
2009 ◽  
Vol 78 (2) ◽  
pp. 783-792 ◽  
Author(s):  
Oranart Matangkasombut ◽  
Roongtiwa Wattanawaraporn ◽  
Keiko Tsuruda ◽  
Masaru Ohara ◽  
Motoyuki Sugai ◽  
...  

ABSTRACT Cytolethal distending toxin (CDT) is a bacterial toxin that induces G2/M cell cycle arrest, cell distension, and/or apoptosis in mammalian cells. It is produced by several Gram-negative species and may contribute to their pathogenicity. The catalytic subunit CdtB has homology with DNase I and may act as a genotoxin. However, the mechanism by which CdtB leads to cell death is not yet clearly understood. Here, we used Saccharomyces cerevisiae as a model to study the molecular pathways involved in the function of CdtB from Aggregatibacter actinomycetemcomitans, a cause of aggressive periodontitis. We show that A. actinomycetemcomitans CdtB (AaCdtB) expression induces S/G2 arrest and death in a DNase-catalytic residue and nuclear localization-dependent manner in haploid yeasts. Yeast strains defective in homologous recombination (HR) repair, but not other DNA repair pathways, are hypersensitive to AaCdtB, suggesting that HR is required for survival upon CdtB expression. In addition, yeast does not harbor the substrate for the other activity proposed for CdtB function, which is phosphatidylinositol-3,4,5-triphosphate phosphatase. Thus, these results suggest that direct DNA-damaging activity alone is sufficient for CdtB toxicity. To investigate how CdtB induces cell death, we examined the effect of CdtB in yeast strains with mutations in apoptotic regulators. Our results suggest that yeast death occurs independently of the yeast metacaspase gene YCA1 and the apoptosis-inducing factor AIF1 but is partially dependent on histone H2B serine 10 phosphorylation. Therefore, we report here the evidence that AaCdtB causes DNA damage that leads to nonapoptotic death in yeast and the first mutation that confers resistance to CdtB.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kalyan Mahapatra ◽  
Sujit Roy

AbstractAs like in mammalian system, the DNA damage responsive cell cycle checkpoint functions play crucial role for maintenance of genome stability in plants through repairing of damages in DNA and induction of programmed cell death or endoreduplication by extensive regulation of progression of cell cycle. ATM and ATR (ATAXIA-TELANGIECTASIA-MUTATED and -RAD3-RELATED) function as sensor kinases and play key role in the transmission of DNA damage signals to the downstream components of cell cycle regulatory network. The plant-specific NAC domain family transcription factor SOG1 (SUPPRESSOR OF GAMMA RESPONSE 1) plays crucial role in transducing signals from both ATM and ATR in presence of double strand breaks (DSBs) in the genome and found to play crucial role in the regulation of key genes involved in cell cycle progression, DNA damage repair, endoreduplication and programmed cell death. Here we report that Arabidopsis exposed to high salinity shows generation of oxidative stress induced DSBs along with the concomitant induction of endoreduplication, displaying increased cell size and DNA ploidy level without any change in chromosome number. These responses were significantly prominent in SOG1 overexpression line than wild-type Arabidopsis, while sog1 mutant lines showed much compromised induction of endoreduplication under salinity stress. We have found that both ATM-SOG1 and ATR-SOG1 pathways are involved in the salinity mediated induction of endoreduplication. SOG1was found to promote G2-M phase arrest in Arabidopsis under salinity stress by downregulating the expression of the key cell cycle regulators, including CDKB1;1, CDKB2;1, and CYCB1;1, while upregulating the expression of WEE1 kinase, CCS52A and E2Fa, which act as important regulators for induction of endoreduplication. Our results suggest that Arabidopsis undergoes endoreduplicative cycle in response to salinity induced DSBs, showcasing an adaptive response in plants under salinity stress.


1993 ◽  
Vol 13 (9) ◽  
pp. 5829-5842
Author(s):  
P Zheng ◽  
D S Fay ◽  
J Burton ◽  
H Xiao ◽  
J L Pinkham ◽  
...  

SPK1 was originally discovered in an immunoscreen for tyrosine-protein kinases in Saccharomyces cerevisiae. We have used biochemical and genetic techniques to investigate the function of this gene and its encoded protein. Hybridization of an SPK1 probe to an ordered genomic library showed that SPK1 is adjacent to PEP4 (chromosome XVI L). Sporulation of spk1/+ heterozygotes gave rise to spk1 spores that grew into microcolonies but could not be further propagated. These colonies were greatly enriched for budded cells, especially those with large buds. Similarly, eviction of CEN plasmids bearing SPK1 from cells with a chromosomal SPK1 disruption yielded viable cells with only low frequency. Spk1 protein was identified by immunoprecipitation and immunoblotting. It was associated with protein-Ser, Thr, and Tyr kinase activity in immune complex kinase assays. Spk1 was localized to the nucleus by immunofluorescence. The nucleotide sequence of the SPK1 5' noncoding region revealed that SPK1 contains two MluI cell cycle box elements. These elements confer S-phase-specific transcription to many genes involved in DNA synthesis. Northern (RNA) blotting of synchronized cells verified that the SPK1 transcript is coregulated with other MluI box-regulated genes. The SPK1 upstream region also includes a domain highly homologous to sequences involved in induction of RAD2 and other excision repair genes by agents that induce DNA damage. spk1 strains were hypersensitive to UV irradiation. Taken together, these findings indicate that SPK1 is a dual-specificity (Ser/Thr and Tyr) protein kinase that is essential for viability. The cell cycle-dependent transcription, presence of DNA damage-related sequences, requirement for UV resistance, and nuclear localization of Spk1 all link this gene to a crucial S-phase-specific role, probably as a positive regulator of DNA synthesis.


2018 ◽  
Author(s):  
Dustin Lane

Programmed cell death signaling networks are frequently activated to coordinate the process of cell differentiation, and a variety of apoptotic events can mediate the process. This can include the ligation of death receptors, the activation of downstream caspases, and the induction of chromatin fragmentation, and all of these events can occur without downstream induction of death. Importantly, regulators of programmed cell death also have established roles in mediating differentiation. This review will provide an overview of apoptosis and its regulation by Inhibitors of Apoptosis (IAPs) and Bcl-2 family members. It will then outline the cross-talk between NF-ĸB and apoptotic signaling in the regulation of apoptosis before discussing the function of these regulators in the control of cell differentiation. It will end on a discussion of how a DNA damage-directed, cell cycle-dependent differentiation program may be controlled across multiple passages through cell cycle, and will assert that the failure to properly differentiate is the underlying cause of cancer.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Toshinori Ozaki ◽  
Akira Nakagawara ◽  
Hiroki Nagase

A proper DNA damage response (DDR), which monitors and maintains the genomic integrity, has been considered to be a critical barrier against genetic alterations to prevent tumor initiation and progression. The representative tumor suppressor p53 plays an important role in the regulation of DNA damage response. When cells receive DNA damage, p53 is quickly activated and induces cell cycle arrest and/or apoptotic cell death through transactivating its target genes implicated in the promotion of cell cycle arrest and/or apoptotic cell death such asp21WAF1,BAX, andPUMA. Accumulating evidence strongly suggests that DNA damage-mediated activation as well as induction of p53 is regulated by posttranslational modifications and also by protein-protein interaction. Loss of p53 activity confers growth advantage and ensures survival in cancer cells by inhibiting apoptotic response required for tumor suppression. RUNX family, which is composed of RUNX1, RUNX2, and RUNX3, is a sequence-specific transcription factor and is closely involved in a variety of cellular processes including development, differentiation, and/or tumorigenesis. In this review, we describe a background of p53 and a functional collaboration between p53 and RUNX family in response to DNA damage.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 578-578 ◽  
Author(s):  
Peter G Smith ◽  
Tary Traore ◽  
Steve Grossman ◽  
Usha Narayanan ◽  
Jennifer S Carew ◽  
...  

Abstract Abstract 578 MLN4924 is an investigational small molecule inhibitor of NEDD8-activating enzyme that has shown clinical activity in a Phase I clinical trial in Acute Myelogenous Leukemia (AML). To identify potential combination partners of MLN4924 we performed a high-throughput viability screen in AML cells with 40 approved and investigational agents. In vitro characterization of AML cell lines revealed two distinct cell cycle phenotypes suggesting alternate mechanism of action following MLN4924 inhibition of NAE. One group demonstrated moderate S-phase accumulation with greater than 4N DNA content consistent with DNA-rereplication as a result of CDT1 dysregulation. The second group demonstrated distinct and rapid accumulation of subG1 cells without S-phase accumulation or DNA re-replication suggesting induction of apoptosis and cell death. These observations led us to choose two cells lines representative of each mechanism to understand potential for synergy in AML cells. Two hypomethylating agents were included in the screen (decitabine and azacitidine) and were found to be synergistic with MLN4924 by Combination Index and Blending Synergy Analysis. These data were confirmed with a second NAE inhibitor that is structurally dissimilar to MLN4924. The combination of azacitidine and MLN4924 were shown to result in significantly increased DNA-damage and cell death compared to single agent alone as measured by Western Blotting and FACS analysis of cell cycle distributions. In vivo studies were performed in HL-60 and THP-1 xenografts using MLN4924 on a clinically relevant dosing schedule twice weekly. Single agent azacitidine at its Maximum Tolerated Dose (MTD) had minimal activity in the HL-60 model and was combined with a sub-optimal dose of MLN4924 that when combined induced complete and sustained tumor regressions. The mechanism for the apparent synthetic lethality in this in vivo model is currently under evaluation; however it is supported by a dramatic elevation in DNA damage and cleaved caspase-3 in vivo in the combination arm. A second xenograft model (THP-1) that was also insensitive to single agent azacitidine treatment underwent complete and sustained tumor regressions when combined with MLN4924. Thus MLN4924 and azacitidine can combine to produce synergistic antitumor activity in pre-clinical models of AML. Coupled with their non-overlapping clinical toxicities these data suggest the potential for future combination studies in clinical trials. Disclosures: Smith: Millennium Pharmaceuticals: Employment. Traore:Millennium Pharmaceuticals: Employment. Grossman:Millennium Pharmaceuticals: Employment. Narayanan:Millennium Pharmaceuticals: Employment. Carew:Millennium Pharmaceuticals: Research Funding. Lublinksky:Millennium Pharmaceuticals: Employment. Kuranda:Millennium Pharmaceuticals: Employment. Milhollen:Millennium Pharmaceuticals: Employment.


2002 ◽  
Vol 13 (8) ◽  
pp. 2626-2638 ◽  
Author(s):  
Shinichiro Enomoto ◽  
Lynn Glowczewski ◽  
Judith Berman

When telomerase is absent and/or telomeres become critically short, cells undergo a progressive decline in viability termed senescence. The telomere checkpoint model predicts that cells will respond to a damaged or critically short telomere by transiently arresting and activating repair of the telomere. We examined the senescence of telomerase-deficient Saccharomyces cerevisiae at the cellular level to ask if the loss of telomerase activity triggers a checkpoint response. As telomerase-deficient mutants were serially subcultured, cells exhibited a progressive decline in average growth rate and an increase in the number of cells delayed in the G2/M stage of the cell cycle. MEC3, MEC1, andDDC2, genes important for the DNA damage checkpoint response, were required for the cell cycle delay in telomerase-deficient cells. In contrast, TEL1,RAD9, and RAD53, genes also required for the DNA damage checkpoint response, were not required for the G2/M delay in telomerase-deficient cells. We propose that the telomere checkpoint is distinct from the DNA damage checkpoint and requires a specific set of gene products to delay the cell cycle and presumably to activate telomerase and/or other telomere repair activities.


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