scholarly journals Archaeal DNA Repair Mechanisms

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1472
Author(s):  
Craig J. Marshall ◽  
Thomas J. Santangelo

Archaea often thrive in environmental extremes, enduring levels of heat, pressure, salinity, pH, and radiation that prove intolerable to most life. Many environmental extremes raise the propensity for DNA damaging events and thus, impact DNA stability, placing greater reliance on molecular mechanisms that recognize DNA damage and initiate accurate repair. Archaea can presumably prosper in harsh and DNA-damaging environments in part due to robust DNA repair pathways but surprisingly, no DNA repair pathways unique to Archaea have been described. Here, we review the most recent advances in our understanding of archaeal DNA repair. We summarize DNA damage types and their consequences, their recognition by host enzymes, and how the collective activities of many DNA repair pathways maintain archaeal genomic integrity.

2020 ◽  
Vol 21 (19) ◽  
pp. 7365
Author(s):  
Jehad F. Alhmoud ◽  
Ayman G. Mustafa ◽  
Mohammed Imad Malki

DNA repair plays an essential role in protecting cells that are repeatedly exposed to endogenous or exogenous insults that can induce varying degrees of DNA damage. Any defect in DNA repair mechanisms results in multiple genomic changes that ultimately may result in mutation, tumor growth, and/or cell apoptosis. Furthermore, impaired repair mechanisms can also lead to genomic instability, which can initiate tumorigenesis and development of hematological malignancy. This review discusses recent findings and highlights the importance of DNA repair components and the impact of their aberrations on hematological malignancies.


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.


2020 ◽  
Vol 22 (1) ◽  
pp. 6
Author(s):  
Ievgeniia Gazo ◽  
Roman Franěk ◽  
Radek Šindelka ◽  
Ievgen Lebeda ◽  
Sahana Shivaramu ◽  
...  

DNA damage caused by exogenous or endogenous factors is a common challenge for developing fish embryos. DNA damage repair (DDR) pathways help organisms minimize adverse effects of DNA alterations. In terms of DNA repair mechanisms, sturgeons represent a particularly interesting model due to their exceptional genome plasticity. Sterlet (Acipenser ruthenus) is a relatively small species of sturgeon. The goal of this study was to assess the sensitivity of sterlet embryos to model genotoxicants (camptothecin, etoposide, and benzo[a]pyrene), and to assess DDR responses. We assessed the effects of genotoxicants on embryo survival, hatching rate, DNA fragmentation, gene expression, and phosphorylation of H2AX and ATM kinase. Exposure of sterlet embryos to 1 µM benzo[a]pyrene induced low levels of DNA damage accompanied by ATM phosphorylation and xpc gene expression. Conversely, 20 µM etoposide exposure induced DNA damage without activation of known DDR pathways. Effects of 10 nM camptothecin on embryo development were stage-specific, with early stages, before gastrulation, being most sensitive. Overall, this study provides foundational information for future investigation of sterlet DDR pathways.


2010 ◽  
Vol 2010 ◽  
pp. 1-32 ◽  
Author(s):  
Rihito Morita ◽  
Shuhei Nakane ◽  
Atsuhiro Shimada ◽  
Masao Inoue ◽  
Hitoshi Iino ◽  
...  

DNA is subjected to many endogenous and exogenous damages. All organisms have developed a complex network of DNA repair mechanisms. A variety of different DNA repair pathways have been reported: direct reversal, base excision repair, nucleotide excision repair, mismatch repair, and recombination repair pathways. Recent studies of the fundamental mechanisms for DNA repair processes have revealed a complexity beyond that initially expected, with inter- and intrapathway complementation as well as functional interactions between proteins involved in repair pathways. In this paper we give a broad overview of the whole DNA repair system and focus on the molecular basis of the repair machineries, particularly inThermus thermophilusHB8.


Author(s):  
Paulina Nguyen-Powanda ◽  
Bernard Robaire

Abstract The efficiency of antioxidant defense system decreases with aging, thus resulting in high levels of reactive oxygen species (ROS) and DNA damage in spermatozoa. This damage can lead to genetic disorders in the offspring. There are limited studies investigating the effects of the total loss of antioxidants, such as superoxide dismutase-1 (SOD1), in male germ cells as they progress through spermatogenesis. In this study, we evaluated the effects of aging and removing SOD1 (in male germ cells of SOD1-null (Sod1−/−) mice) in order to determine the potential mechanism(s) of DNA damage in these cells. Immunohistochemical analysis showed an increase in lipid peroxidation and DNA damage in the germ cells of aged wild-type (WT) and Sod1−/− mice of all age. Immunostaining of OGG1, a marker of base excision repair (BER), increased in aged WT and young Sod1−/− mice. In contrast, immunostaining intensity of LIGIV and RAD51, markers of non-homologous end-joining (NHEJ) and homologous recombination (HR), respectively, decreased in aged and Sod1−/− mice. Gene expression analysis showed similar results with altered mRNA expression of these key DNA repair transcripts in pachytene spermatocytes and round spermatids of aged and Sod1−/− mice. Our study indicates that DNA repair pathway markers of BER, NHEJ, and HR are differentially regulated as a function of aging and oxidative stress in spermatocytes and spermatids, and aging enhances the repair response to increased oxidative DNA damage, whereas impairments in other DNA repair mechanisms may contribute to the increase in DNA damage caused by aging and the loss of SOD1.


2019 ◽  
Vol 20 (5) ◽  
pp. 1146 ◽  
Author(s):  
Marta Włodarczyk ◽  
Grażyna Nowicka

Obesity has been recognized to increase the risk of such diseases as cardiovascular diseases, diabetes, and cancer. It indicates that obesity can impact genome stability. Oxidative stress and inflammation, commonly occurring in obesity, can induce DNA damage and inhibit DNA repair mechanisms. Accumulation of DNA damage can lead to an enhanced mutation rate and can alter gene expression resulting in disturbances in cell metabolism. Obesity-associated DNA damage can promote cancer growth by favoring cancer cell proliferation and migration, and resistance to apoptosis. Estimation of the DNA damage and/or disturbances in DNA repair could be potentially useful in the risk assessment and prevention of obesity-associated metabolic disorders as well as cancers. DNA damage in people with obesity appears to be reversible and both weight loss and improvement of dietary habits and diet composition can affect genome stability.


Reproduction ◽  
2001 ◽  
pp. 31-39 ◽  
Author(s):  
WM Baarends ◽  
R van der Laan ◽  
JA Grootegoed

In mammals, there is a complex and intriguing relationship between DNA repair and gametogenesis. DNA repair mechanisms are involved not only in the repair of different types of DNA damage in developing germline cells, but also take part in the meiotic recombination process. Furthermore, the DNA repair mechanisms should tolerate mutations occurring during gametogenesis, to a limited extent. In the present review, several gametogenic aspects of DNA mismatch repair, homologous recombination repair and postreplication repair are discussed. In addition, the role of DNA damage-induced cell cycle checkpoint control is considered briefly. It appears that many genes encoding proteins that take part in DNA repair mechanisms show enhanced or specialized expression during mammalian gametogenesis, and several gene knockout mouse models show male or female infertility. On the basis of such knowledge and models, future experiments may provide more information about the precise relationship between DNA repair, chromatin dynamics, and genomic stability versus instability during gametogenesis.


Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 862 ◽  
Author(s):  
Alexander Schulz ◽  
Felix Meyer ◽  
Anna Dubrovska ◽  
Kerstin Borgmann

The current preclinical and clinical findings demonstrate that, in addition to the conventional clinical and pathological indicators that have a prognostic value in radiation oncology, the number of cancer stem cells (CSCs) and their inherent radioresistance are important parameters for local control after radiotherapy. In this review, we discuss the molecular mechanisms of CSC radioresistance attributable to DNA repair mechanisms and the development of CSC-targeted therapies for tumor radiosensitization. We also discuss the current challenges in preclinical and translational CSC research including the high inter- and intratumoral heterogeneity, plasticity of CSCs, and microenvironment-stimulated tumor cell reprogramming.


2021 ◽  
Vol 22 (24) ◽  
pp. 13296
Author(s):  
Mariarosaria De Falco ◽  
Mariarita De Felice

All organisms have evolved many DNA repair pathways to counteract the different types of DNA damages. The detection of DNA damage leads to distinct cellular responses that bring about cell cycle arrest and the induction of DNA repair mechanisms. In particular, DNA double-strand breaks (DSBs) are extremely toxic for cell survival, that is why cells use specific mechanisms of DNA repair in order to maintain genome stability. The choice among the repair pathways is mainly linked to the cell cycle phases. Indeed, if it occurs in an inappropriate cellular context, it may cause genome rearrangements, giving rise to many types of human diseases, from developmental disorders to cancer. Here, we analyze the most recent remarks about the main pathways of DSB repair with the focus on homologous recombination. A thorough knowledge in DNA repair mechanisms is pivotal for identifying the most accurate treatments in human diseases.


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