scholarly journals Distinct roles of yeast MEC and RAD checkpoint genes in transcriptional induction after DNA damage and implications for function.

1996 ◽  
Vol 7 (5) ◽  
pp. 703-718 ◽  
Author(s):  
G L Kiser ◽  
T A Weinert
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Cycle Arrest ◽  
Positive Feedback Circuit ◽  
Different Types ◽  
Atm Gene ◽  
Checkpoint Genes ◽  
Transcriptional Induction

In eukaryotic cells, checkpoint genes cause arrest of cell division when DNA is damaged or when DNA replication is blocked. In this study of budding yeast checkpoint genes, we identify and characterize another role for these checkpoint genes after DNA damage-transcriptional induction of genes. We found that three checkpoint genes (of six genes tested) have strong and distinct roles in transcriptional induction in four distinct pathways of regulation (each defined by induction of specific genes). MEC1 mediates the response in three transcriptional pathways, RAD53 mediates two of these pathways, and RAD17 mediates but a single pathway. The three other checkpoint genes (including RAD9) have small (twofold) but significant roles in transcriptional induction in all pathways. One of the pathways that we identify here leads to induction of MEC1 and RAD53 checkpoint genes themselves. This suggests a positive feedback circuit that may increase the cell's ability to respond to DNA damage. We make two primary conclusions from these studies. First, MEC1 appears to be the key regulator because it is required for all responses (both transcriptional and cell cycle arrest), while other genes serve only a subset of these responses. Second, the two types of responses, transcriptional induction and cell cycle arrest, appear distinct because both require MEC1 yet only cell cycle arrest requires RAD9. These and other results were used to formulate a working model of checkpoint gene function that accounts for roles of different checkpoint genes in different responses and after different types of damage. The conclusion that the yeast MEC1 gene is a key regulator also has implications for the role of a putative human homologue, the ATM gene.

scholarly journals p38 Mitogen-Activated Protein Kinase- and HuR-Dependent Stabilization of p21Cip1 mRNA Mediates the G1/S Checkpoint

2009 ◽  
Vol 29 (16) ◽  
pp. 4341-4351 ◽  
Author(s):  
Vanesa Lafarga ◽  
Ana Cuadrado ◽  
Isabel Lopez de Silanes ◽  
Rocio Bengoechea ◽  
Oscar Fernandez-Capetillo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Protein Kinase ◽  
Cell Cycle Arrest ◽  
P38 Mapk ◽  
Mitogen Activated Protein Kinase ◽  
Γ Radiation ◽  
Cycle Arrest ◽  
Mitogen Activated Protein

ABSTRACT Activation of p38 mitogen-activated protein kinase (MAPK) plays an important role in the G2/M cell cycle arrest induced by DNA damage, but little is known about the role of this signaling pathway in the G1/S transition. Upregulation of the cyclin-dependent kinase inhibitor p21Cip1 is thought to make a major contribution to the G1/S cell cycle arrest induced by γ radiation. We show here that inhibition of p38 MAPK impairs p21Cip1 accumulation and, as a result, the ability of cells to arrest in G1 in response to γ radiation. We found that p38 MAPK induces p21Cip1 mRNA stabilization, without affecting its transcription or the stability of the protein. In particular, p38 MAPK phosphorylates the mRNA binding protein HuR on Thr118, which results in cytoplasmic accumulation of HuR and its enhanced binding to the p21Cip1 mRNA. Our findings help to understand the emerging role of p38 MAPK in the cellular responses to DNA damage and reveal the existence of p53-independent networks that cooperate in modulating p21Cip1 levels at the G1/S checkpoint.

scholarly journals The role of FOXO3 in DNA damage response in thyrocytes

2011 ◽  
Vol 18 (5) ◽  
pp. 555-564 ◽  
Author(s):  
Antje Klagge ◽  
Carl Weidinger ◽  
Kerstin Krause ◽  
Beate Jessnitzer ◽  
Monika Gutknecht ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Cellular Response ◽  
Wild Type ◽  
Cycle Arrest ◽  
Damage Repair ◽  
Cell Clones ◽  
Human Wild Type

Members of the forkhead box-O (FOXO) transcription factors family play an important role in stress defence. FOXO3 deregulation has recently been identified as a hallmark of thyroid carcinogenesis. In this study, we explore the role of FOXO3 in defence of oxidative stress in normal thyrocytes. Stable rat thyroid cell lines were generated expressing either the human wild-type FOXO3, a constitutively activating FOXO3 mutant, or the empty control vector. Cell clones were characterised for proliferation, function and morphology. Hydrogen peroxide and UV irradiation were used to induce oxidative stress. Changes in FOXO3 activity, induction of cell cycle arrest or apoptosis and kinetics of DNA damage repair were analysed. Upregulation of FOXO3 in thyrocytes resulted in decreased proliferation and changes in morphology, but did not affect differentiation. Hydrogen peroxide stimulated the expression of the FOXO3 target genes growth arrest and DNA damage-inducible protein 45 α (Gadd45α) and Bcl-2 interacting mediator of cell death (BIM) and induced programmed cell death in cells with overexpression of the human wild-type FOXO3. In contrast, UV irradiation resulted in a distinct cellular response with activation of FOXO3-c-Jun-N-terminal kinase-Gadd45α signalling and induction of cell cycle arrest at the G2-M-checkpoint. This was accompanied by FOXO3-induced DNA damage repair as evidenced by lower DNA breaks over time in a comet assay in FOXO3 cell clones compared with control cells. In conclusion, FOXO3 is a pivotal relay in the coordination of the cellular response to genotoxic stress in the thyroid. Depending on the stimulus, FOXO3 induces either cell cycle arrest or apoptosis. Conversely, FOXO3 inactivation in thyroid cancers is consistent with genomic instability and loss of cell cycle control.

scholarly journals The Role of JMY in p53 Regulation.

2018 ◽  
Author(s):  
Francesco Pezzella ◽  
Omanma Adighibe
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Adhesion Molecules ◽  
Actin Nucleation ◽  
Cycle Arrest

Following an event damaging the DNA, p53 levels increases inducing cell cycle arrest or apoptosis. JMY protein is a transcription co-factor involved in p53 regulation. After a DNA damage, also JMY levels increase and, as this protein accumulates in the nucleus, it forms a complex with P300 and Strap1 which increases the ability of p53 to induce transcription of proteins triggering apoptosis but not cell cycle. Therefore, Increase levels of JMY “direct” p53 activity toward triggering apoptosis. JMY expression is also linked to increased motility as it downregulates the expression of adhesion molecules of the Cadherin family and induces actin nucleation, making the cell less adhesive and more mobile. According to the scenario this gene can therefore have both a suppressive or a tumour promoting activity.

scholarly journals H2AX Is Required for Cell Cycle Arrest via the p53/p21 Pathway

2009 ◽  
Vol 29 (10) ◽  
pp. 2828-2840 ◽  
Author(s):  
Michalis Fragkos ◽  
Jaana Jurvansuu ◽  
Peter Beard
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Cellular Response ◽  
Replication Fork ◽  
Mitotic Catastrophe ◽  
Adeno Associated Virus ◽  
Cycle Arrest ◽  
And Diffusion

ABSTRACT Phosphorylation of H2AX (γH2AX) is an early sign of DNA damage induced by replication stalling. However, the role of H2AX in the repair of this type of DNA damage is still unclear. In this study, we used an inactivated adeno-associated virus (AAV) to induce a stalled replication fork signal and investigate the function of γH2AX. The cellular response to AAV provides a unique model to study γH2AX function, because the infection causes pannuclear H2AX phosphorylation without any signs of damage to the host genome. We found that pannuclear γH2AX formation is a result of ATR overactivation and diffusion but is independent of ATM. The inhibition of H2AX with RNA interference or the use of H2AX-deficient cells showed that γH2AX is dispensable for the formation and maintenance of DNA repair foci induced by stalled replication. However, in the absence of H2AX, the AAV-containing cells showed proteosome-dependent degradation of p21, followed by caspase-dependent mitotic catastrophe. In contrast, H2AX-proficient cells as well as H2AX-complemented H2AX−/− cells reacted by increasing p21 levels and arresting the cell cycle. The results establish a new role for H2AX in the p53/p21 pathway and indicate that H2AX is required for p21-induced cell cycle arrest after replication stalling.

scholarly journals The Role of JMY in p53 Regulation.

2018 ◽  
Author(s):  
Francesco Pezzella ◽  
Omanma Adighibe
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Adhesion Molecules ◽  
Actin Nucleation ◽  
Cycle Arrest

Following an event damaging the DNA, p53 levels increases inducing cell cycle arrest or apoptosis. JMY protein is a transcription co-factor involved in p53 regulation. After a DNA damage, also JMY levels increase and, as this protein accumulates in the nucleus, it forms a complex with P300 and Strap1 which increases the ability of p53 to induce transcription of proteins triggering apoptosis but not cell cycle. Therefore, Increase levels of JMY “direct” p53 activity toward triggering apoptosis. JMY expression is also linked to increased motility as it downregulates the expression of adhesion molecules of the Cadherin family and induces actin nucleation, making the cell less adhesive and more mobile. According to the scenario this gene can therefore have both a suppressive or a tumour promoting activity.

The role of p53 and cell death by apoptosis and necrosis in 4-hydroperoxycyclophosphamide-induced limb malformations

Development ◽  
1998 ◽  
Vol 125 (16) ◽  
pp. 3225-3234
Author(s):  
S.A. Moallem ◽  
B.F. Hales
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Death ◽  
Drug Treatment ◽  
Cell Cycle Arrest ◽  
Wild Type ◽  
Cycle Arrest ◽  
Limb Malformations ◽  
Apoptosis And Necrosis

The exposure of embryonic murine limbs in vitro to an activated analog of cyclophosphamide, 4-hydroperoxycyclophosphamide (4OOH-CPA), induced limb malformations and apoptosis. The purpose of this study was to investigate the role of the tumor suppressor/cell cycle checkpoint gene, p53, and of cell cycle arrest in the response of the limbs to cyclophosphamide. Limbs, excised on day 12 of gestation from wild-type, heterozygous or homozygous p53-knockout transgenic murine embryos, were treated with vehicle (water) or 4OOH-CPA (0.3, 1.0 or 3.0 microgram/ml) and cultured for 6 days. Exposure of wild-type (+/+) limbs to 4OOH-CPA resulted in limb malformations, and reduced limb areas and developmental scores. The homozygous (−/−) limbs were dramatically more sensitive to the effects of 4OOH-CPA, as assessed by limb morphology, area and score. Heterozygous limbs exposed to the drug were intermediate for each parameter. Apoptosis, as assessed by the formation of a DNA ladder, was increased in drug-exposed wild-type limbs, but not in the drug-exposed homozygous limbs. Light and electron microscopy examination of the limbs revealed that drug treatment of wild-type limbs induced the morphological changes typical of apoptosis, particularly in the interdigital regions. In contrast, there was no evidence of apoptosis in homozygous limbs exposed to 4-OOH-CPA; morphological characteristics of necrosis such as cell membrane breakdown, mitochondrial swelling and cellular disintegration were evident throughout these limbs. Heterozygous limbs had cells dying with the characteristics of both apoptosis and necrosis. Fragments of poly(ADP-ribose) polymerase characteristic of necrosis predominated in the drug-treated heterozygous and homozygous limbs. 4-OOH-CPA-treatment of limbs from wild-type embryos led to arrest of the cell cycle at the G1/S phase. No cell cycle arrest was observed after drug treatment of homozygous limbs, in which populations of cells in S and G2/M phases, as well as a population of sub G1 cells, were found. Thus, the presence of p53 and of p53-dependent apoptosis protect organogenesis-stage limbs from insult with a teratogen. The absence of p53 may decrease DNA repair capacity and contribute to the accumulation of DNA damage in limb cells and their daughter cells; the failure of apoptosis to eliminate cells with DNA damage may result in increased cell death by necrosis and major limb malformations.

scholarly journals Cell-type-specific role of CHK2 in mediating DNA damage-induced G2 cell cycle arrest

Oncogenesis ◽  
2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Marijn T. M. van Jaarsveld ◽  
Difan Deng ◽  
Diana Ordoñez-Rueda ◽  
Malte Paulsen ◽  
Erik A. C. Wiemer ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Specific Role ◽  
Cell Type ◽  
Cycle Arrest ◽  
Cell Type Specific ◽  
G2 Cell Cycle Arrest

scholarly journals On Broken Ne(c)ks and Broken DNA: The Role of Human NEKs in the DNA Damage Response

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 507
Author(s):  
Isadora Carolina Betim Pavan ◽  
Andressa Peres de Oliveira ◽  
Pedro Rafael Firmino Dias ◽  
Fernanda Luisa Basei ◽  
Luidy Kazuo Issayama ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Dna Damage Response ◽  
Ataxia Telangiectasia ◽  
General Role ◽  
Cycle Arrest ◽  
Damage Response ◽  
Repair Pathways

NIMA-related kinases, or NEKs, are a family of Ser/Thr protein kinases involved in cell cycle and mitosis, centrosome disjunction, primary cilia functions, and DNA damage responses among other biological functional contexts in vertebrate cells. In human cells, there are 11 members, termed NEK1 to 11, and the research has mainly focused on exploring the more predominant roles of NEKs in mitosis regulation and cell cycle. A possible important role of NEKs in DNA damage response (DDR) first emerged for NEK1, but recent studies for most NEKs showed participation in DDR. A detailed analysis of the protein interactions, phosphorylation events, and studies of functional aspects of NEKs from the literature led us to propose a more general role of NEKs in DDR. In this review, we express that NEK1 is an activator of ataxia telangiectasia and Rad3-related (ATR), and its activation results in cell cycle arrest, guaranteeing DNA repair while activating specific repair pathways such as homology repair (HR) and DNA double-strand break (DSB) repair. For NEK2, 6, 8, 9, and 11, we found a role downstream of ATR and ataxia telangiectasia mutated (ATM) that results in cell cycle arrest, but details of possible activated repair pathways are still being investigated. NEK4 shows a connection to the regulation of the nonhomologous end-joining (NHEJ) repair of DNA DSBs, through recruitment of DNA-PK to DNA damage foci. NEK5 interacts with topoisomerase IIβ, and its knockdown results in the accumulation of damaged DNA. NEK7 has a regulatory role in the detection of oxidative damage to telomeric DNA. Finally, NEK10 has recently been shown to phosphorylate p53 at Y327, promoting cell cycle arrest after exposure to DNA damaging agents. In summary, this review highlights important discoveries of the ever-growing involvement of NEK kinases in the DDR pathways. A better understanding of these roles may open new diagnostic possibilities or pharmaceutical interventions regarding the chemo-sensitizing inhibition of NEKs in various forms of cancer and other diseases.

scholarly journals Role of Mis Localization of DNA Repair Factors in Cell Cycle Arrest

2019 ◽  
Vol 116 (3) ◽  
pp. 76a
Author(s):  
Manasvita Vashisth ◽  
Sangkyun Cho ◽  
Dennis Discher
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Cell Cycle Arrest ◽  
Cycle Arrest

scholarly journals Design, Synthesis and Pharmacological Evaluation of Three Novel Dehydroabietyl Piperazine Dithiocarbamate Ruthenium (II) Polypyridyl Complexes as Potential Antitumor Agents: DNA Damage, Cell Cycle Arrest and Apoptosis Induction

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1453
Author(s):  
Haoran Wang ◽  
Jianhua Wei ◽  
Hong Jiang ◽  
Ye Zhang ◽  
Caina Jiang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Antitumor Agents ◽  
Mechanistic Study ◽  
Ros Generation ◽  
Polypyridyl Complexes ◽  
Expression Levels ◽  
Cycle Arrest ◽  
Study Results

The use of cisplatin is severely limited by its toxic side-effects, which has spurred chemists to employ different strategies in the development of new metal-based anticancer agents. Here, three novel dehydroabietyl piperazine dithiocarbamate ruthenium (II) polypyridyl complexes (6a–6c) were synthesized as antitumor agents. Compounds 6a and 6c exhibited better in vitro antiproliferative activity against seven tumor cell lines than cisplatin, they displayed no evident resistance in the cisplatin-resistant cell line A549/DPP. Importantly, 6a effectively inhibited tumor growth in the T-24 xenograft mouse model in comparison with cisplatin. Gel electrophoresis assay indicated that DNA was the potential targets of 6a and 6c, and the upregulation of p-H2AX confirmed this result. Cell cycle arrest studies demonstrated that 6a and 6c arrested the cell cycle at G1 phase, accompanied by the upregulation of the expression levels of the antioncogene p27 and the down-regulation of the expression levels of cyclin E. In addition, 6a and 6c caused the apoptosis of tumor cells along with the upregulation of the expression of Bax, caspase-9, cytochrome c, intracellular Ca2+ release, reactive oxygen species (ROS) generation and the downregulation of Bcl-2. These mechanistic study results suggested that 6a and 6c exerted their antitumor activity by inducing DNA damage, and consequently causing G1 stage arrest and the induction of apoptosis.

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