DNA Repair最新文献_第6页

The role of human PrimPol active site residue Gln48 in catalysis and complex formation with DNA 人PrimPol活性位点残基Gln48在催化和与DNA形成复合物中的作用

IF 3 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-07-11 DOI: 10.1016/j.dnarep.2025.103867

Elizaveta O. Boldinova , Alena V. Makarova

{"title":"The role of human PrimPol active site residue Gln48 in catalysis and complex formation with DNA","authors":"Elizaveta O. Boldinova , Alena V. Makarova","doi":"10.1016/j.dnarep.2025.103867","DOIUrl":"10.1016/j.dnarep.2025.103867","url":null,"abstract":"<div><div>Human PrimPol is a primase-polymerase involved in the mechanism of DNA synthesis reinitiation at the sites of DNA damage and replication fork collapse. By using its DNA primase activity, PrimPol synthesizes DNA primers which can be utilized by high-fidelity DNA polymerases to resume replication downstream of the damaged site. Disruption of PrimPol function may be associated with an increased risk of cancer and ophthalmologic diseases. Understanding the detailed mechanism of catalysis and regulation of PrimPol activity is crucial for predicting how mutations and polymorphisms affect enzyme function within the cell. In this study, we conducted a biochemical investigation of the role of the conserved Gln48 residue in the PrimPol active site in DNA synthesis by replacing glutamine with a positively charged arginine (Q48R) or a negatively charged glutamic acid (Q48E). The PrimPol variant with the Q48R substitution is also represented in the NCBI dbSNP (rs939272279 A/G). Both substitutions resulted in impaired complex formation of PrimPol with DNA and significantly reduced the catalytic activity of the enzyme, indicating the important role of the Gln48 residue in forming contacts with the template DNA and active site organization. The data obtained suggest that the Q48R substitution may disrupt PrimPol functions.</div></div>","PeriodicalId":300,"journal":{"name":"DNA Repair","volume":"152 ","pages":"Article 103867"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

DNA damage response of U2OS cells to low doses of gamma radiation delivered at very low dose rate U2OS细胞对低剂量极低剂量率γ辐射的DNA损伤反应

IF 2.7 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-07-23 DOI: 10.1016/j.dnarep.2025.103875

Magdalena Płódowska , Wiktoria Krakowiak , Aneta Węgierek-Ciuk , Katarzyna Gałczyńska , Kinga Pasińska , Daniel Sobota , Paweł Wołowiec , Janusz Braziewicz , Anna Lankoff , Michał Arabski , Andrzej Wojcik , Halina Lisowska

{"title":"DNA damage response of U2OS cells to low doses of gamma radiation delivered at very low dose rate","authors":"Magdalena Płódowska , Wiktoria Krakowiak , Aneta Węgierek-Ciuk , Katarzyna Gałczyńska , Kinga Pasińska , Daniel Sobota , Paweł Wołowiec , Janusz Braziewicz , Anna Lankoff , Michał Arabski , Andrzej Wojcik , Halina Lisowska","doi":"10.1016/j.dnarep.2025.103875","DOIUrl":"10.1016/j.dnarep.2025.103875","url":null,"abstract":"<div><div>The DNA damage response (DDR) of cells to low dose and low dose rate ionizing radiation is weak and remains a matter of controversy. The response can be studied by exposing cells to a low adapting dose (AD) and, subsequently to a high challenging dose (CD), where the response is strong. The aim of the present investigation was to analyse the DDR in cells exposed to very low dose rate AD and a high dose rate CD, with special focus on the role of the ATM kinase. U2OS cells (with wild type p53) were exposed to gamma radiation AD of 5.9 mGy at 31 µGy/h and of 10.5 mGy at 55 µGy/h. ATM was inhibited by addition of KU-55933. Adapted cells were exposed to a CD of 1 Gy photon radiation at 1 Gy/min. The studied endpoints included kinetics of 53BP1 foci formation and decay, cell cycle progression and gene expression. In some experiments, ATM was inhibited by KU-55933. AD alone led to a significant increase in 53BP1 foci, even in the presence of KU-55933, and it modulated the response to CD. KU-55933 failed to inhibit the induction of foci by AD and AD+CD, while foci induction by CD alone was inhibited. KU-55933 potentiated the G2 block in AD+CD-exposed cells. Gene expression was modulated by AD. In conclusion, AD differentially modulated the response of cells when given alone and after the CD, in absence and presence of KU-55933.</div></div>","PeriodicalId":300,"journal":{"name":"DNA Repair","volume":"152 ","pages":"Article 103875"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

FBH1 and the replication stress response: Implications for genome stability and cancer development FBH1和复制应激反应：对基因组稳定性和癌症发展的影响

IF 3 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-06-26 DOI: 10.1016/j.dnarep.2025.103865

Joshua L. Turner, Jennifer M. Mason

引用次数: 0

The role of DNA repair deficiency in lipid accumulation: A proof-of-concept study DNA修复缺陷在脂质积累中的作用：一项概念验证研究

IF 2.7 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-08-05 DOI: 10.1016/j.dnarep.2025.103880

Houan Tu , Ibbo Willems , Anastasiya Mircheva , Victoria Claudino Bastos , Twan van den Beucken , Ludwig Dubois , Alexander H.V. Remels , Frederik-Jan van Schooten , Roger W.L. Godschalk , Sabine A.S. Langie

{"title":"The role of DNA repair deficiency in lipid accumulation: A proof-of-concept study","authors":"Houan Tu , Ibbo Willems , Anastasiya Mircheva , Victoria Claudino Bastos , Twan van den Beucken , Ludwig Dubois , Alexander H.V. Remels , Frederik-Jan van Schooten , Roger W.L. Godschalk , Sabine A.S. Langie","doi":"10.1016/j.dnarep.2025.103880","DOIUrl":"10.1016/j.dnarep.2025.103880","url":null,"abstract":"<div><div>Animal models suggest an association between base excision repair (BER) deficiency and increased risk of obesity. To mechanistically investigate the effect of BER deficiency on intracellular lipid accumulation, we studied metabolic activity in <em>in vitro</em> BER knockdown (KD) models, targeting <em>MutY DNA Glycosylase (MUTYH), Nth Like DNA Glycosylase 1 (NTHL1) and 8-Oxoguanine DNA Glycosylase (OGG1)</em>. We hypothesized that exposing BER deficient cells to lipids leads to reduced mitochondrial function and enhanced intracellular lipid accumulation. Stable BER KD models were generated in HepG2 cells using lentiviral shRNAs. KD was confirmed by qRT-PCR and BER activity was assessed using a modified comet assay. Upon exposure to a mixture of oleic and palmitic acid, DNA damage and mitochondrial copy number were only altered in <em>NTHL1</em>-KD cells, but all KD cells accumulated more intracellular lipids compared to <em>lacZ</em> control cells as determined by Oil-Red-O (ORO) staining. Compared to control cells, exposure to the fatty acid mixture increased proton leak in <em>MUTYH</em>-KD cells, indicating impaired mitochondrial function. Moreover, all KD cells showed reduced β-oxidation activity when exposed to the fatty acid mixture. Overall, this study shows that BER deficient HepG2 cells are more prone to accumulated lipids, which was associated with impaired mitochondrial function. These findings are relevant in understanding the underlying mechanisms that modulate the sensitivity of a person to accumulate lipids and increase their risk of developing metabolic diseases such as obesity and fatty liver disease.</div></div>","PeriodicalId":300,"journal":{"name":"DNA Repair","volume":"152 ","pages":"Article 103880"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144780927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The model moss Physcomitrium patens relies heavily on homologous recombination to repair DNA double-strand breaks 模式苔藓壶状菌主要依靠同源重组修复DNA双链断裂

IF 2.7 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-08-05 DOI: 10.1016/j.dnarep.2025.103881

Ayako N. Sakamoto , Yuichiro Yokota , Pierre-François Perroud , Yasuhiro Oshima , Fabien Nogué , Yoshihiro Hase

{"title":"The model moss Physcomitrium patens relies heavily on homologous recombination to repair DNA double-strand breaks","authors":"Ayako N. Sakamoto , Yuichiro Yokota , Pierre-François Perroud , Yasuhiro Oshima , Fabien Nogué , Yoshihiro Hase","doi":"10.1016/j.dnarep.2025.103881","DOIUrl":"10.1016/j.dnarep.2025.103881","url":null,"abstract":"<div><div>We previously showed that moss (<em>Physcomitrium patens</em>) cells are highly radioresistant and suggested that <em>P. patens</em> uses an efficient mechanism to repair DNA double-strand breaks (DSBs). Homologous recombination (HR), canonical non-homologous end-joining, and alternative end-joining are the major pathways used to repair DSBs. To identify the DSB repair pathway used in <em>P. patens</em>, we generated knockout (KO) plants for <em>LIG4</em>, <em>POLQ</em>, and <em>RAD51B</em>, which play major roles in canonical non-homologous end-joining, alternative end-joining, and HR, respectively. The KO plants were irradiated with γ-rays, and their radioresistance was evaluated. Although wild-type (WT), <em>lig4</em>, and <em>polq</em> plants showed comparable radioresistance, that of <em>rad51b</em> plants was drastically reduced. The radioresistance of <em>rad51b polq</em> plants was further reduced, whereas that of <em>rad51b lig4</em> plants was similar to that of <em>rad51b</em>. Under γ-irradiation conditions at which the dry weight of the plants was reduced to 50 %, single base substitutions were predominantly induced in WT, <em>lig4</em>, and <em>polq</em> plants. In contrast, drastic sequence alterations, such as large deletions with or without insertions, chromosome inversions, or translocations, were induced in <em>rad51b</em> and <em>rad51b polq</em> plants. These results suggest that <em>P. patens</em> primarily uses the HR pathway for DSB repair, even in the presence of other pathways. Flow cytometry analysis of the WT and KO plants revealed that the majority of cells subjected to irradiation were in late S/G2 phase, suggesting that the sister chromatid served as a template for HR.</div></div>","PeriodicalId":300,"journal":{"name":"DNA Repair","volume":"152 ","pages":"Article 103881"},"PeriodicalIF":2.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

From cooperation to conflicts – A complicated relationship between transcription and replication 从合作到冲突——转录与复制之间的复杂关系

IF 3 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-07-16 DOI: 10.1016/j.dnarep.2025.103872

Syed Shahid Musvi , Tatiana N. Moiseeva

引用次数: 0

Proofreading of mismatches within primer-template junctions by Escherichia coli DNA polymerase I in vitro and in vivo 大肠杆菌DNA聚合酶I在体外和体内对引物-模板连接错配的校正

IF 3 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-06-23 DOI: 10.1016/j.dnarep.2025.103864

Hui-Lan Chang , Kang-Yi Su , Steven D. Goodman , Yung-Chu Chuang , Shen-Jyue Hsu , Yi-Kai Fang , Hsiao-Pei Yu , Cheng-Hao Fang , Ya-Chien Yang , Sui-Yuan Chang , Woei-horng Fang

{"title":"Proofreading of mismatches within primer-template junctions by Escherichia coli DNA polymerase I in vitro and in vivo","authors":"Hui-Lan Chang , Kang-Yi Su , Steven D. Goodman , Yung-Chu Chuang , Shen-Jyue Hsu , Yi-Kai Fang , Hsiao-Pei Yu , Cheng-Hao Fang , Ya-Chien Yang , Sui-Yuan Chang , Woei-horng Fang","doi":"10.1016/j.dnarep.2025.103864","DOIUrl":"10.1016/j.dnarep.2025.103864","url":null,"abstract":"<div><div><em>Escherichia coli</em> DNA polymerase I (Pol I) possesses a 3’ to 5’ proofreading function. Using a non-inhibitory <em>in vitro</em> proofreading assay and MALDI-TOF MS analysis, we demonstrated the Pol I proofreading function was effective at removal of mismatches within the primer-template junction. Mismatches of 1–4 nucleotides (nt) from the primer 3′ end could be completely or partially corrected, with no additional editing observed further upstream. A backward movement mechanism was proposed involving distributive backtracking of polymerase along the template to remove non-fully complemented primers in order for DNA synthesis to recover. Co-editing DNA substrates containing two mismatches, one at 1–4-nt of the primer 3’ end and the other outside of normal proofreading range, confirmed our distributive backtracking hypothesis. Additionally, a time course analysis revealed proofreading of internal mismatches was a non-processive reaction. To further confirm the validity of our proofreading model, we used <em>in vivo</em>, phagemid-derived nicked C-C substrates. Transformation results were consistent with the notion that mismatches located less than 4-nt upstream of the 3′ end could be successfully proofread. <em>In vivo</em> proofreading of double mismatches also supports our model of polymerase backtracking for internal mismatch editing.</div></div>","PeriodicalId":300,"journal":{"name":"DNA Repair","volume":"152 ","pages":"Article 103864"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144488960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transcription-coupled repair of crosslinking DNA damage 交联DNA损伤的转录偶联修复

IF 3 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-07-16 DOI: 10.1016/j.dnarep.2025.103869

Rebecca Roddan, Lucy R. Henderson, Malitha Ratnaweera, Peter J. McHugh

引用次数: 0

DNA damage response and genomic instability disorder: Meeting report of the 20th Ataxia-Telangiectasia Workshop (ATW-2024) in conjunction with the 15th international symposium on DNA damage response & human disease (isDDRHD-2024) DNA损伤反应与基因组不稳定性疾病：第20届共济失调-毛细血管扩张研讨会（ATW-2024）与第15届DNA损伤反应与人类疾病国际研讨会（isDDRHD-2024）会议报告

IF 3 3区生物学

DNA Repair Pub Date : 2025-08-01 Epub Date: 2025-06-17 DOI: 10.1016/j.dnarep.2025.103860

Yisui Xia , Zhao-Qi Wang , Xingzhi Xu

引用次数: 0

"Yin-Yang" of PARP1 in genotoxic and inflammatory response PARP1基因毒性和炎症反应的“阴阳”关系