scholarly journals Maintenance of Genome Stability by Ubiquitination of DNA Repair Proteins in Mammalian Development and Disease

Author(s):  
Mikio Shimada
Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 530
Author(s):  
Marlo K. Thompson ◽  
Robert W. Sobol ◽  
Aishwarya Prakash

The earliest methods of genome editing, such as zinc-finger nucleases (ZFN) and transcription activator-like effector nucleases (TALENs), utilize customizable DNA-binding motifs to target the genome at specific loci. While these approaches provided sequence-specific gene-editing capacity, the laborious process of designing and synthesizing recombinant nucleases to recognize a specific target sequence, combined with limited target choices and poor editing efficiency, ultimately minimized the broad utility of these systems. The discovery of clustered regularly interspaced short palindromic repeat sequences (CRISPR) in Escherichia coli dates to 1987, yet it was another 20 years before CRISPR and the CRISPR-associated (Cas) proteins were identified as part of the microbial adaptive immune system, by targeting phage DNA, to fight bacteriophage reinfection. By 2013, CRISPR/Cas9 systems had been engineered to allow gene editing in mammalian cells. The ease of design, low cytotoxicity, and increased efficiency have made CRISPR/Cas9 and its related systems the designer nucleases of choice for many. In this review, we discuss the various CRISPR systems and their broad utility in genome manipulation. We will explore how CRISPR-controlled modifications have advanced our understanding of the mechanisms of genome stability, using the modulation of DNA repair genes as examples.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Katerina Zabrady ◽  
Matej Zabrady ◽  
Peter Kolesar ◽  
Arthur W. H. Li ◽  
Aidan J. Doherty

AbstractCRISPR-Cas pathways provide prokaryotes with acquired “immunity” against foreign genetic elements, including phages and plasmids. Although many of the proteins associated with CRISPR-Cas mechanisms are characterized, some requisite enzymes remain elusive. Genetic studies have implicated host DNA polymerases in some CRISPR-Cas systems but CRISPR-specific replicases have not yet been discovered. We have identified and characterised a family of CRISPR-Associated Primase-Polymerases (CAPPs) in a range of prokaryotes that are operonically associated with Cas1 and Cas2. CAPPs belong to the Primase-Polymerase (Prim-Pol) superfamily of replicases that operate in various DNA repair and replication pathways that maintain genome stability. Here, we characterise the DNA synthesis activities of bacterial CAPP homologues from Type IIIA and IIIB CRISPR-Cas systems and establish that they possess a range of replicase activities including DNA priming, polymerisation and strand-displacement. We demonstrate that CAPPs operonically-associated partners, Cas1 and Cas2, form a complex that possesses spacer integration activity. We show that CAPPs physically associate with the Cas proteins to form bespoke CRISPR-Cas complexes. Finally, we propose how CAPPs activities, in conjunction with their partners, may function to undertake key roles in CRISPR-Cas adaptation.


2020 ◽  
Vol 21 (14) ◽  
pp. 5048
Author(s):  
Chih-Wei Chen ◽  
Ning Tsao ◽  
Wei Zhang ◽  
Zee-Fen Chang

NME3 is a member of the nucleoside diphosphate kinase (NDPK) family that binds to the mitochondrial outer membrane to stimulate mitochondrial fusion. In this study, we showed that NME3 knockdown delayed DNA repair without reducing the cellular levels of nucleotide triphosphates. Further analyses revealed that NME3 knockdown increased fragmentation of mitochondria, which in turn led to mitochondrial oxidative stress-mediated DNA single-strand breaks (SSBs) in nuclear DNA. Re-expression of wild-type NME3 or inhibition of mitochondrial fission markedly reduced SSBs and facilitated DNA repair in NME3 knockdown cells, while expression of N-terminal deleted mutant defective in mitochondrial binding had no rescue effect. We further showed that disruption of mitochondrial fusion by knockdown of NME4 or MFN1 also caused mitochondrial oxidative stress-mediated genome instability. In conclusion, the contribution of NME3 to redox-regulated genome stability lies in its function in mitochondrial fusion.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bahri Evren ◽  
Sami Yılmaz ◽  
Neşe Karadağ ◽  
Ayşe Çıkım Sertkaya ◽  
Ömercan Topaloğlu ◽  
...  

AbstractMalignant thyroid lesions are the most common malignancy of the endocrine glands with increasing rates in the last two decades. Papillary thyroid cancer is the most common thyroid malignancy. In our study, we aimed to quantitatively evaluate the levels of DNA repair proteins MSH2, MLH1, MGMT, which are representative blocks of patients diagnosed with papillary carcinoma, chronic thyroiditis, or colloidal goiter. Total or subtotal thyroidectomy material of 90 patients diagnosed with papillary carcinoma, nodular colloidal goiter, or chronic thyroiditis between 2009 and 2012 were retrospectively evaluated. Tissue samples obtained from paraffin blocks were stained with MGMT, MSH2, MLH1 proteins and their immunohistochemistry was evaluated. Prepared sections were examined qualitatively by an impartial pathologist and a clinician, taking into account the staining method under the trinocular light microscope. Although there was no statistically significant difference in MGMT, MSH2, MLH1, follicular cell positivity, staining intensity, and immunoreactivity values, papillary carcinoma cases showed a higher rate of follicular cell positivity, and this difference was more pronounced between papillary carcinoma and colloidal goiter. In the MSH2 follicular cell positivity evaluation, the difference between chronic thyroiditis and colloidal goiter was significant (p = 0.023). The difference between chronic thyroiditis and colloidal goiter was significant in the MSH2 staining intensity evaluation (p = 0.001). The difference between chronic thyroiditis and colloidal goiter was significant in MLH1 immunoreactivity evaluation (p = 0.012). Papillary carcinoma cases were demonstrated by nuclear staining only for MSH2 and MLH1 proteins as opposed to hyperplastic nodules. The higher levels of expression of DNA repair genes in malignant tumors compared to benign tumors are attributed to the functional activation of DNA repair genes. Further studies are needed for DNA repair proteins to be a potential test in the development and progression of thyroid cancer.


2010 ◽  
Vol 79 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Min Wu ◽  
Huang Huang ◽  
Weidong Zhang ◽  
Shibichakravarthy Kannan ◽  
Andrew Weaver ◽  
...  

ABSTRACTAlthough DNA repair proteins in bacteria are critical for pathogens' genome stability and for subverting the host defense, the role of host DNA repair proteins in response to bacterial infection is poorly defined. Here, we demonstrate, for the first time, that infection with the Gram-negative bacteriumPseudomonas aeruginosasignificantly altered the expression and enzymatic activity of 8-oxoguanine DNA glycosylase (OGG1) in lung epithelial cells. Downregulation of OGG1 by a small interfering RNA strategy resulted in severe DNA damage and cell death. In addition, acetylation of OGG1 is required for host responses to bacterial genotoxicity, as mutations of OGG1 acetylation sites increased Cockayne syndrome group B (CSB) protein expression. These results also indicate that CSB may be involved in DNA repair activity during infection. Furthermore, OGG1 knockout mice exhibited increased lung injury after infection withP. aeruginosa, as demonstrated by higher myeloperoxidase activity and lipid peroxidation. Together, our studies indicate thatP. aeruginosainfection induces significant DNA damage in host cells and that DNA repair proteins play a critical role in the host response toP. aeruginosainfection, serving as promising targets for the treatment of this condition and perhaps more broadly Gram-negative bacterial infections.


2001 ◽  
Vol 36 (9) ◽  
pp. 1483-1494 ◽  
Author(s):  
Rebecca L. Persinger ◽  
Robert Melamede ◽  
Ivan Bespalov ◽  
Susan Wallace ◽  
Douglas J. Taatjes ◽  
...  

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1779 ◽  
Author(s):  
Raghavendra A. Shamanna ◽  
Deborah L. Croteau ◽  
Jong-Hyuk Lee ◽  
Vilhelm A. Bohr

Aging, the universal phenomenon, affects human health and is the primary risk factor for major disease pathologies. Progeroid diseases, which mimic aging at an accelerated rate, have provided cues in understanding the hallmarks of aging. Mutations in DNA repair genes as well as in telomerase subunits are known to cause progeroid syndromes. Werner syndrome (WS), which is characterized by accelerated aging, is an autosomal-recessive genetic disorder. Hallmarks that define the aging process include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulation of nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. WS recapitulates these hallmarks of aging and shows increased incidence and early onset of specific cancers. Genome integrity and stability ensure the normal functioning of the cell and are mainly guarded by the DNA repair machinery and telomeres. WRN, being a RecQ helicase, protects genome stability by regulating DNA repair pathways and telomeres. Recent advances in WS research have elucidated WRN’s role in DNA repair pathway choice regulation, telomere maintenance, resolution of complex DNA structures, epigenetic regulation, and stem cell maintenance.


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