scholarly journals Connections between the Cell Cycle and the DNA Damage Response in Plants

2021 ◽  
Vol 22 (17) ◽  
pp. 9558
Author(s):  
Naomie Gentric ◽  
Pascal Genschik ◽  
Sandra Noir

Due to their sessile lifestyle, plants are especially exposed to various stresses, including genotoxic stress, which results in altered genome integrity. Upon the detection of DNA damage, distinct cellular responses lead to cell cycle arrest and the induction of DNA repair mechanisms. Interestingly, it has been shown that some cell cycle regulators are not only required for meristem activity and plant development but are also key to cope with the occurrence of DNA lesions. In this review, we first summarize some important regulatory steps of the plant cell cycle and present a brief overview of the DNA damage response (DDR) mechanisms. Then, the role played by some cell cycle regulators at the interface between the cell cycle and DNA damage responses is discussed more specifically.

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 504
Author(s):  
Takayuki Saitoh ◽  
Tsukasa Oda

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by genomic instability. MM cells present various forms of genetic instability, including chromosomal instability, microsatellite instability, and base-pair alterations, as well as changes in chromosome number. The tumor microenvironment and an abnormal DNA repair function affect genetic instability in this disease. In addition, states of the tumor microenvironment itself, such as inflammation and hypoxia, influence the DNA damage response, which includes DNA repair mechanisms, cell cycle checkpoints, and apoptotic pathways. Unrepaired DNA damage in tumor cells has been shown to exacerbate genomic instability and aberrant features that enable MM progression and drug resistance. This review provides an overview of the DNA repair pathways, with a special focus on their function in MM, and discusses the role of the tumor microenvironment in governing DNA repair mechanisms.


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.


2019 ◽  
Vol 47 (16) ◽  
pp. 8502-8520 ◽  
Author(s):  
Lin Zhang ◽  
Da-Qiang Li

Abstract Microrchidia family CW-type zinc finger 2 (MORC2) is a newly identified chromatin remodeling enzyme with an emerging role in DNA damage response (DDR), but the underlying mechanism remains largely unknown. Here, we show that poly(ADP-ribose) polymerase 1 (PARP1), a key chromatin-associated enzyme responsible for the synthesis of poly(ADP-ribose) (PAR) polymers in mammalian cells, interacts with and PARylates MORC2 at two residues within its conserved CW-type zinc finger domain. Following DNA damage, PARP1 recruits MORC2 to DNA damage sites and catalyzes MORC2 PARylation, which stimulates its ATPase and chromatin remodeling activities. Mutation of PARylation residues in MORC2 results in reduced cell survival after DNA damage. MORC2, in turn, stabilizes PARP1 through enhancing acetyltransferase NAT10-mediated acetylation of PARP1 at lysine 949, which blocks its ubiquitination at the same residue and subsequent degradation by E3 ubiquitin ligase CHFR. Consequently, depletion of MORC2 or expression of an acetylation-defective PARP1 mutant impairs DNA damage-induced PAR production and PAR-dependent recruitment of DNA repair proteins to DNA lesions, leading to enhanced sensitivity to genotoxic stress. Collectively, these findings uncover a previously unrecognized mechanistic link between MORC2 and PARP1 in the regulation of cellular response to DNA damage.


2017 ◽  
Author(s):  
Emma Haapaniemi ◽  
Sandeep Botla ◽  
Jenna Persson ◽  
Bernhard Schmierer ◽  
Jussi Taipale

AbstractWe report here that genome editing by CRISPR/Cas9 induces a p53-mediated DNA damage response and cell cycle arrest. Transient inhibition of p53 prevents this response, and increases the rate of homologous recombination more than five-fold. This provides a way to improve precision genome editing of normal cells, but warrants caution in using CRISPR for human therapies until the mechanism of the activation of p53 is elucidated.


2020 ◽  
Vol 3 (5) ◽  
pp. e201900494 ◽  
Author(s):  
Akinori Takahashi ◽  
Toru Suzuki ◽  
Shou Soeda ◽  
Shohei Takaoka ◽  
Shungo Kobori ◽  
...  

The biological significance of deadenylation in global gene expression is not fully understood. Here, we show that the CCR4–NOT deadenylase complex maintains expression of mRNAs, such as those encoding transcription factors, cell cycle regulators, DNA damage response–related proteins, and metabolic enzymes, at appropriate levels in the liver. Liver-specific disruption of Cnot1, encoding a scaffold subunit of the CCR4–NOT complex, leads to increased levels of mRNAs for transcription factors, cell cycle regulators, and DNA damage response–related proteins because of reduced deadenylation and stabilization of these mRNAs. CNOT1 suppression also results in an increase of immature, unspliced mRNAs (pre-mRNAs) for apoptosis-related and inflammation-related genes and promotes RNA polymerase II loading on their promoter regions. In contrast, mRNAs encoding metabolic enzymes become less abundant, concomitant with decreased levels of these pre-mRNAs. Lethal hepatitis develops concomitantly with abnormal mRNA expression. Mechanistically, the CCR4–NOT complex targets and destabilizes mRNAs mainly through its association with Argonaute 2 (AGO2) and butyrate response factor 1 (BRF1) in the liver. Therefore, the CCR4–NOT complex contributes to liver homeostasis by modulating the liver transcriptome through mRNA deadenylation.


2019 ◽  
Author(s):  
Alexendar R. Perez ◽  
Laura Sala ◽  
Richard K. Perez ◽  
Joana A. Vidigal

Off-target cleavage by Cas9 can confound measurements of cell proliferation/viability in CRISPR assays by eliciting a DNA-damage response that includes cell cycle arrest1-3. This gene-independent toxicity has been documented in large scale assays2-4 and shown to be a source of false-positives when libraries are populated by promiscuous guide RNAs (gRNAs)7. To address this, we developed CSC, a computational method to correct for the effect of specificity on gRNA depletion. We applied CSC to screening data from the Cancer Dependency Map and show that it significantly improves the specificity of CRISPR-Cas9 essentiality screens while preserving known gene essentialities even for genes targeted by highly pro-miscuous guides. We packaged CSC in a Python software to allow its seamless integration into current CRISPR analysis pipelines and improve the sensitivity of essentiality screens for repetitive genomic loci.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1265-1265
Author(s):  
Christine von Klitzing ◽  
Florian Bassermann ◽  
Stephan W. Morris ◽  
Christian Peschel ◽  
Justus Duyster

Abstract The nuclear interaction partner of ALK (NIPA) is a nuclear protein identified by our group in a screen for NPM-ALK interaction partners. We recently reported that NIPA is an F-box protein that assembles with SKP1, Cul1 and Roc1 to establish a novel SCF-type E3 ubiquitin ligase. The formation of the SCFNIPA complex is regulated by cell cycle-dependent phosphorylation of NIPA that restricts SCFNIPA assembly from G1- to late S-phase, thus allowing its substrates to be active from late S-phase throughout mitosis. Proteins involved in cell cycle regulation frequently play a role in DNA damage checkpoints. We therefore sought to determine whether NIPA has a function in the cellular response to genotoxic stress. For this reason we treated NIH/3T3 cells with various DNA-damaging agents. Surprisingly, we observed phosphorylation of NIPA in response to some of these agents, including UV radiation. This phosphorylation was cell cycle phase independent and thus independent of the physiological cell cycle dependent phosphorylation of NIPA. The relevant phosphorylation site is identical to the respective site in the course of cell cycle-dependent phosphorylation of NIPA. Thus, phosphorylation of NIPA upon genotoxic stress would inactivate the SCFNIPA complex in a cell cycle independent manner. Interestingly, this phosphorylation site lies within a consensus site of the Chk1/Chk2 checkpoint kinases. These kinases are central to DNA damage checkpoint signaling. Chk1 is activated by ATR in response to blocked replication forks as they occur after treatment with UV. We performed experiments using the ATM/ATR inhibitor caffeine and the Chk1 inhibitor SB218078 to investigate a potential role of Chk1 in NIPA phosphorylation. Indeed, we found both inhibitors to prevent UV-induced phosphorylation of NIPA. Current experiments applying Chk1 knock-out cells will unravel the role of Chk1 in NIPA phosphorylation. Additional experiments were performed to investigate a function for NIPA in DNA-damage induced apoptosis. In this regard, we observed overexpression of NIPA WT to induce apoptosis in response to UV, whereas no proapoptotic effect was seen with the phosphorylation deficient NIPA mutant. Therefore, the phosphorylated form of NIPA may be involved in apoptotic signaling pathways. In summary, we present data suggesting a cell cycle independent function for NIPA. This activity is involved in DNA damage response and may be involved in regulating apoptosis upon genotoxic stress.


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