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Valenzisi P, Marabitti V, Pichierri P, Franchitto A. WRNIP1 prevents transcription-associated genomic instability. eLife 2024; 12:RP89981. [PMID: 38488661 PMCID: PMC10942783 DOI: 10.7554/elife.89981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024] Open
Abstract
R-loops are non-canonical DNA structures that form during transcription and play diverse roles in various physiological processes. Disruption of R-loop homeostasis can lead to genomic instability and replication impairment, contributing to several human diseases, including cancer. Although the molecular mechanisms that protect cells against such events are not fully understood, recent research has identified fork protection factors and DNA damage response proteins as regulators of R-loop dynamics. In this study, we identify the Werner helicase-interacting protein 1 (WRNIP1) as a novel factor that counteracts transcription-associated DNA damage upon replication perturbation. Loss of WRNIP1 leads to R-loop accumulation, resulting in collisions between the replisome and transcription machinery. We observe co-localization of WRNIP1 with transcription/replication complexes and R-loops after replication perturbation, suggesting its involvement in resolving transcription-replication conflicts. Moreover, WRNIP1-deficient cells show impaired replication restart from transcription-induced fork stalling. Notably, transcription inhibition and RNase H1 overexpression rescue all the defects caused by loss of WRNIP1. Importantly, our findings highlight the critical role of WRNIP1 ubiquitin-binding zinc finger (UBZ) domain in preventing pathological persistence of R-loops and limiting DNA damage, thereby safeguarding genome integrity.
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Affiliation(s)
- Pasquale Valenzisi
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
| | - Veronica Marabitti
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
| | - Pietro Pichierri
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
| | - Annapaola Franchitto
- Section of Mechanisms Biomarkers and Models, Department of Environment and Health, Istituto Superiore di SanitaRomeItaly
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2
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Sack T, Dhavarasa P, Szames D, O'Brien S, Angers S, Kelley SO. CRISPR Screening in Tandem with Targeted mtDNA Damage Reveals WRNIP1 Essentiality. ACS Chem Biol 2023; 18:2599-2609. [PMID: 38054633 DOI: 10.1021/acschembio.3c00620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
A major impediment to the characterization of mtDNA repair mechanisms in comparison to nuclear DNA repair mechanisms is the difficulty of specifically addressing mitochondrial damage. Using a mitochondria-penetrating peptide, we can deliver DNA-damaging agents directly to mitochondria, bypassing the nuclear compartment. Here, we describe the use of an mtDNA-damaging agent in tandem with CRISPR/Cas9 screening for the genome-wide discovery of factors essential for mtDNA damage response. Using mitochondria-targeted doxorubicin (mtDox), we generate mtDNA double-strand breaks (mtDSBs) specifically in this organelle. Combined with an untargeted doxorubicin (Dox) screen, we identify genes with significantly greater essentiality during mitochondrial versus nuclear DNA damage. We characterize the essentiality of our top hit, WRNIP1─observed here for the first time to respond to mtDNA damage. We further investigate the mitochondrial role of WRNIP1 in innate immune signaling and nuclear genome maintenance, outlining a model that experimentally supports mitochondrial turnover in response to mtDSBs.
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Affiliation(s)
- Tanja Sack
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Piriththiv Dhavarasa
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Daniel Szames
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Siobhan O'Brien
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Stephane Angers
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Shana O Kelley
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Chemistry, Faculty of Arts and Science, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- Department of Chemistry, Weinberg College of Arts & Sciences, Northwestern University, Evanston, Illinois 60208, United States
- Chan Zuckerberg Biohub Chicago, Chicago, Illinois 60607, United States
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3
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Xia D, Zhu X, Wang Y, Gong P, Su HS, Xu X. Implications of ubiquitination and the maintenance of replication fork stability in cancer therapy. Biosci Rep 2023; 43:BSR20222591. [PMID: 37728310 PMCID: PMC10550789 DOI: 10.1042/bsr20222591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 08/21/2023] [Accepted: 09/19/2023] [Indexed: 09/21/2023] Open
Abstract
DNA replication forks are subject to intricate surveillance and strict regulation by sophisticated cellular machinery. Such close regulation is necessary to ensure the accurate duplication of genetic information and to tackle the diverse endogenous and exogenous stresses that impede this process. Stalled replication forks are vulnerable to collapse, which is a major cause of genomic instability and carcinogenesis. Replication stress responses, which are organized via a series of coordinated molecular events, stabilize stalled replication forks and carry out fork reversal and restoration. DNA damage tolerance and repair pathways such as homologous recombination and Fanconi anemia also contribute to replication fork stabilization. The signaling network that mediates the transduction and interplay of these pathways is regulated by a series of post-translational modifications, including ubiquitination, which affects the activity, stability, and interactome of substrates. In particular, the ubiquitination of replication protein A and proliferating cell nuclear antigen at stalled replication forks promotes the recruitment of downstream regulators. In this review, we describe the ubiquitination-mediated signaling cascades that regulate replication fork progression and stabilization. In addition, we discuss the targeting of replication fork stability and ubiquitination system components as a potential therapeutic approach for the treatment of cancer.
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Affiliation(s)
- Donghui Xia
- Shenzhen University General Hospital-Dehua Hospital Joint Research Center on Precision Medicine (sgh-dhhCPM), Dehua Hospital, Dehua, Quanzhou 362500, China
- Guangdong Key Laboratory for Genome Stability and Disease Prevention, Carson International Cancer Center, Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen, Guangdong 518060, China
- State Key Laboratory of Agro-biotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xuefei Zhu
- Department of General Surgery, Institute of Precision Diagnosis and Treatment of Gastrointestinal Tumors and Carson International Cancer Center, Shenzhen University General Hospital, Shenzhen University Medical School, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Ying Wang
- State Key Laboratory of Agro-biotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Peng Gong
- Department of General Surgery, Institute of Precision Diagnosis and Treatment of Gastrointestinal Tumors and Carson International Cancer Center, Shenzhen University General Hospital, Shenzhen University Medical School, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Hong-Shu Su
- Shenzhen University General Hospital-Dehua Hospital Joint Research Center on Precision Medicine (sgh-dhhCPM), Dehua Hospital, Dehua, Quanzhou 362500, China
| | - Xingzhi Xu
- Shenzhen University General Hospital-Dehua Hospital Joint Research Center on Precision Medicine (sgh-dhhCPM), Dehua Hospital, Dehua, Quanzhou 362500, China
- Guangdong Key Laboratory for Genome Stability and Disease Prevention, Carson International Cancer Center, Marshall Laboratory of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen, Guangdong 518060, China
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Sack T, Dhavarasa P, Szames D, O'Brien S, Angers S, Kelley SO. CRISPR Screening in Tandem with Targeted mtDNA Damage Reveals WRNIP1 Essentiality. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560559. [PMID: 37873237 PMCID: PMC10592966 DOI: 10.1101/2023.10.03.560559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
A major impediment to the characterization of mtDNA repair mechanisms, in comparison to nuclear DNA repair mechanisms, is the difficulty of specifically addressing mitochondrial damage. Using a mitochondria-penetrating peptide, we can deliver DNA-damaging agents directly to mitochondria, bypassing the nuclear compartment. Here, we describe the use of a mtDNA-damaging agent in tandem with CRISPR/Cas9 screening for the genome-wide discovery of factors essential for mtDNA damage response. Using mitochondria-targeted doxorubicin (mtDox) we generate mtDNA double-strand breaks (mtDSBs) specifically in this organelle. Combined with an untargeted Dox screen, we identify genes with significantly greater essentiality during mitochondrial versus nuclear DNA damage. We characterize the essentially of our top hit - WRNIP1 - observed here for the first time to respond to mtDNA damage. We further investigate the mitochondrial role of WRNIP1 in innate immune signaling and nuclear genome maintenance, outlining a model that experimentally supports mitochondrial turnover in response to mtDSBs.
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5
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Aliyaskarova U, Baiken Y, Renaud F, Couve S, Kisselev AF, Saparbaev M, Groisman R. NEIL3-mediated proteasomal degradation facilitates the repair of cisplatin-induced DNA damage in human cells. Sci Rep 2023; 13:5174. [PMID: 36997601 PMCID: PMC10063580 DOI: 10.1038/s41598-023-32186-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 03/23/2023] [Indexed: 04/01/2023] Open
Abstract
Anti-neoplastic effect of DNA cross-linking agents such as cisplatin, mitomycin C, and psoralen is attributed to their ability to induce DNA interstrand cross-links (ICLs), which block replication, transcription, and linear repair pathways by preventing DNA strand separation and trigger apoptosis. It is generally agreed that the Fanconi anemia (FA) pathway orchestrates the removal of ICLs by the combined actions of various DNA repair pathways. Recently, attention has been focused on the ability of the NEIL3-initiated base excision repair pathway to resolve psoralen- and abasic site-induced ICLs in an FA-independent manner. Intriguingly, overexpression of NEIL3 is associated with chemo-resistance and poor prognosis in many solid tumors. Here, using loss- and gain-of-function approaches, we demonstrate that NEIL3 confers resistance to cisplatin and participates in the removal of cisplatin-DNA adducts. Proteomic studies reveal that the NEIL3 protein interacts with the 26S proteasome in a cisplatin-dependent manner. NEIL3 mediates proteasomal degradation of WRNIP1, a protein involved in the early step of ICL repair. We propose that NEIL3 participates in the repair of ICL-stalled replication fork by recruitment of the proteasome to ensure a timely transition from lesion recognition to repair via the degradation of early-step vanguard proteins.
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Affiliation(s)
- Umit Aliyaskarova
- Team «Mechanisms of DNA Repair and Carcinogenesis», CNRS UMR 9019, Université Paris-Saclay, Gustave Roussy Cancer Campus, 94805, Villejuif Cedex, France
| | - Yeldar Baiken
- National Laboratory Astana, Nazarbayev University, Astana, Kazakhstan
- School of Sciences and Humanities, Nazarbayev University, Astana, Kazakhstan
- School of Engineering and Digital Sciences, Nazarbayev University, Astana, Kazakhstan
| | - Flore Renaud
- Team «Mechanisms of DNA Repair and Carcinogenesis», CNRS UMR 9019, Université Paris-Saclay, Gustave Roussy Cancer Campus, 94805, Villejuif Cedex, France
- EPHE, PSL University, Paris, France
| | - Sophie Couve
- Team «Mechanisms of DNA Repair and Carcinogenesis», CNRS UMR 9019, Université Paris-Saclay, Gustave Roussy Cancer Campus, 94805, Villejuif Cedex, France
- EPHE, PSL University, Paris, France
| | - Alexei F Kisselev
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, PRB, 720 S. Donahue Dr., Auburn, AL, 36849, USA.
| | - Murat Saparbaev
- Team «Mechanisms of DNA Repair and Carcinogenesis», CNRS UMR 9019, Université Paris-Saclay, Gustave Roussy Cancer Campus, 94805, Villejuif Cedex, France.
| | - Regina Groisman
- Team «Mechanisms of DNA Repair and Carcinogenesis», CNRS UMR 9019, Université Paris-Saclay, Gustave Roussy Cancer Campus, 94805, Villejuif Cedex, France.
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Babu S, Takeuchi Y, Masai I. Banp regulates DNA damage response and chromosome segregation during the cell cycle in zebrafish retina. eLife 2022; 11:74611. [PMID: 35942692 PMCID: PMC9363121 DOI: 10.7554/elife.74611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 07/05/2022] [Indexed: 11/25/2022] Open
Abstract
Btg3-associated nuclear protein (Banp) was originally identified as a nuclear matrix-associated region (MAR)-binding protein and it functions as a tumor suppressor. At the molecular level, Banp regulates transcription of metabolic genes via a CGCG-containing motif called the Banp motif. However, its physiological roles in embryonic development are unknown. Here, we report that Banp is indispensable for the DNA damage response and chromosome segregation during mitosis. Zebrafish banp mutants show mitotic cell accumulation and apoptosis in developing retina. We found that DNA replication stress and tp53-dependent DNA damage responses were activated to induce apoptosis in banp mutants, suggesting that Banp is required for regulation of DNA replication and DNA damage repair. Furthermore, consistent with mitotic cell accumulation, chromosome segregation was not smoothly processed from prometaphase to anaphase in banp morphants, leading to a prolonged M-phase. Our RNA- and ATAC-sequencing identified 31 candidates for direct Banp target genes that carry the Banp motif. Interestingly, a DNA replication fork regulator, wrnip1, and two chromosome segregation regulators, cenpt and ncapg, are included in this list. Thus, Banp directly regulates transcription of wrnip1 for recovery from DNA replication stress, and cenpt and ncapg for chromosome segregation during mitosis. Our findings provide the first in vivo evidence that Banp is required for cell-cycle progression and cell survival by regulating DNA damage responses and chromosome segregation during mitosis. In order for a cell to divide, it must progress through a series of carefully controlled steps known as the cell cycle. First, the cell replicates its DNA and both copies get segregated to opposite ends. The cell then splits into two and each new cell receives a copy of the duplicated genetic material. If any of the stages in the cell cycle become disrupted or mis-regulated this can lead to uncontrolled divisions that may result in cancer. Researchers have often used a structure within the eye known as the retina to study the cell cycle in zebrafish and other animals as cells in the retina rapidly divide in a highly controlled manner. A protein called Banp is known to help stop tumors from growing in humans and mice, but its normal role in the body, particularly the cell cycle, has remained unclear. To investigate, Babu et al. studied the retina of mutant zebrafish that were unable to make the Banp protein. The experiments revealed that two stress responses indicating DNA damage or defects in copying DNA were active in the retinal cells of the mutant zebrafish. This suggested that Banp allows cell to progress through the cell cycle by repairing any DNA damage that may arise during replication. Banp does this by activating the gene for another protein called Wrnip1. Babu et al. also found that Banp helps segregate the two copies of DNA during cell division by promoting the activation of two other proteins called Cenpt and Ncapg. Further experiments identified 31 genes that were directly regulated by Banp. These findings demonstrate that Banp is required for zebrafish cells to be able to accurately copy their DNA and divide in to two new cells. In the future, the work of Babu et al. will provide a useful resource to investigate how tumors grow and spread around the body, and may contribute to the development of new treatments for cancer.
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Affiliation(s)
- Swathy Babu
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Yuki Takeuchi
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Ichiro Masai
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
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Ellegate J, Mastri M, Isenhart E, Krolewski JJ, Chatta G, Kauffman E, Moffitt M, Eng KH. Loss of MAGEC3 Expression Is Associated with Prognosis in Advanced Ovarian Cancers. Cancers (Basel) 2022; 14:cancers14030731. [PMID: 35158998 PMCID: PMC8833712 DOI: 10.3390/cancers14030731] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/21/2022] [Accepted: 01/24/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary Familial studies connect variants in the X-linked gene MAGEC3 to early-onset ovarian cancers. In this retrospective cohort study, we determined that, unlike other MAGE family members, the MAGEC3 protein is normally expressed in ovarian tissue but is lost in half of the ovarian cancers. Similar to other predisposition genes like BRCA2, survival modeling suggests that expression loss is associated with favorable progression-free survival, and continued expression is associated with response to platinum therapy. Because of the assumed antigenicity of MAGE genes, we tested and observed associations with lymphocyte infiltration, NY-ESO-1 seropositivity, and the co-expression of tumor antigens at Xq28. Using transcriptomic modeling, we predicted that MAGEC3 expression is associated with stress-related cell cycle stalling and DNA repair pathway expression. Abstract Rare variants in MAGEC3 are associated with BRCA negative, early-onset ovarian cancers. Given this association, we evaluated the impact of MAGEC3 protein expression on prognosis and transcription. We quantified normal and tumor protein expression of MAGEC3 via immunohistochemistry in n = 394 advanced ovarian cancers, assessed the correlation of these values with clinicopathologic and immunological features and modeled survival using univariate and multivariate models. To extend these results, we quantified MAGEC3 protein expression in n = 180 cancers and used matching RNA sequencing data to determine MAGEC3-associated differentially expressed genes and to build an RNA-based model of MAGEC3 protein levels. This model was tested in a third independent cohort of patients from TCGA’s OV dataset (n = 282). MAGEC3 protein was sporadically lost in ovarian cancers, with half of the cases falling below the 9.5th percentile of normal tissue expression. Cases with MAGEC3 loss demonstrated better progression-free survival [HR = 0.71, p = 0.004], and analyses performed on predicted protein scores were consistent [HR = 0.57 p = 0.002]. MAGEC3 protein was correlated with CD8 protein expression [Pearson’s r = 0.176, p = 0.011], NY-ESO-1 seropositivity, and mRNA expression of tumor antigens at Xq28. Results of gene set enrichment analysis showed that genes associated with MAGEC3 protein expression cluster around G2/M checkpoint (NES = 3.20, FDR < 0.001) and DNA repair (NES = 2.28, FDR < 0.001) hallmark pathways. These results show that MAGEC3 is a prognostic biomarker in ovarian cancer.
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Affiliation(s)
- James Ellegate
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (J.E.J.); (M.M.); (E.I.); (J.J.K.)
| | - Michalis Mastri
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (J.E.J.); (M.M.); (E.I.); (J.J.K.)
| | - Emily Isenhart
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (J.E.J.); (M.M.); (E.I.); (J.J.K.)
| | - John J. Krolewski
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (J.E.J.); (M.M.); (E.I.); (J.J.K.)
| | - Gurkamal Chatta
- Department of Medicine, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA;
| | - Eric Kauffman
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA;
| | - Melissa Moffitt
- Department of Gynecologic Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA;
| | - Kevin H. Eng
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; (J.E.J.); (M.M.); (E.I.); (J.J.K.)
- Department of Biostatistics and Bioinformatics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA
- Correspondence:
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The rarA gene as part of an expanded RecFOR recombination pathway: Negative epistasis and synthetic lethality with ruvB, recG, and recQ. PLoS Genet 2021; 17:e1009972. [PMID: 34936656 PMCID: PMC8735627 DOI: 10.1371/journal.pgen.1009972] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 01/06/2022] [Accepted: 12/01/2021] [Indexed: 11/19/2022] Open
Abstract
The RarA protein, homologous to human WRNIP1 and yeast MgsA, is a AAA+ ATPase and one of the most highly conserved DNA repair proteins. With an apparent role in the repair of stalled or collapsed replication forks, the molecular function of this protein family remains obscure. Here, we demonstrate that RarA acts in late stages of recombinational DNA repair of post-replication gaps. A deletion of most of the rarA gene, when paired with a deletion of ruvB or ruvC, produces a growth defect, a strong synergistic increase in sensitivity to DNA damaging agents, cell elongation, and an increase in SOS induction. Except for SOS induction, these effects are all suppressed by inactivating recF, recO, or recJ, indicating that RarA, along with RuvB, acts downstream of RecA. SOS induction increases dramatically in a rarA ruvB recF/O triple mutant, suggesting the generation of large amounts of unrepaired ssDNA. The rarA ruvB defects are not suppressed (and in fact slightly increased) by recB inactivation, suggesting RarA acts primarily downstream of RecA in post-replication gaps rather than in double strand break repair. Inactivating rarA, ruvB and recG together is synthetically lethal, an outcome again suppressed by inactivation of recF, recO, or recJ. A rarA ruvB recQ triple deletion mutant is also inviable. Together, the results suggest the existence of multiple pathways, perhaps overlapping, for the resolution or reversal of recombination intermediates created by RecA protein in post-replication gaps within the broader RecF pathway. One of these paths involves RarA.
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Zhan S, Siu J, Wang Z, Yu H, Bezabeh T, Deng Y, Du W, Fei P. Focal Point of Fanconi Anemia Signaling. Int J Mol Sci 2021; 22:12976. [PMID: 34884777 PMCID: PMC8657418 DOI: 10.3390/ijms222312976] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/26/2021] [Accepted: 11/26/2021] [Indexed: 12/11/2022] Open
Abstract
Among human genetic diseases, Fanconi Anemia (FA) tops all with its largest number of health complications in nearly all human organ systems, suggesting the significant roles played by FA genes in the maintenance of human health. With the accumulated research on FA, the encoded protein products by FA genes have been building up to the biggest cell defense signaling network, composed of not only 22+ FA proteins but also ATM, ATR, and many other non-FA proteins. The FA D2 group protein (FANCD2) and its paralog form the focal point of FA signaling to converge the effects of its upstream players in response to a variety of cellular insults and simultaneously with downstream players to protect humans from contracting diseases, including aging and cancer. In this review, we update and discuss how the FA signaling crucially eases cellular stresses through understanding its focal point.
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Affiliation(s)
- Sudong Zhan
- University of Hawaii Cancer Center, University of Hawaii, Honolulu, HI 96813, USA; (S.Z.); (Z.W.); (H.Y.)
| | - Jolene Siu
- Student Research Experience Program of University of Hawaii, Honolulu, HI 96822, USA;
| | - Zhanwei Wang
- University of Hawaii Cancer Center, University of Hawaii, Honolulu, HI 96813, USA; (S.Z.); (Z.W.); (H.Y.)
| | - Herbert Yu
- University of Hawaii Cancer Center, University of Hawaii, Honolulu, HI 96813, USA; (S.Z.); (Z.W.); (H.Y.)
| | - Tedros Bezabeh
- Department of Chemistry, University of Guam, Mangilao, GU 96923, USA;
| | - Youping Deng
- Department of Quantitative Health Sciences, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96813, USA;
| | - Wei Du
- Division of Hematology and Oncology, University of Pittsburgh School of Medicine, UPMC Hillman Cancer Center, Pittsburgh, PA 15232, USA;
| | - Peiwen Fei
- University of Hawaii Cancer Center, University of Hawaii, Honolulu, HI 96813, USA; (S.Z.); (Z.W.); (H.Y.)
- Student Research Experience Program of University of Hawaii, Honolulu, HI 96822, USA;
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RNF166 plays a dual role for Lys63-linked ubiquitination and sumoylation of its target proteins. J Neural Transm (Vienna) 2021; 129:463-475. [PMID: 34837535 DOI: 10.1007/s00702-021-02442-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/08/2021] [Indexed: 10/19/2022]
Abstract
Ubiquitination and sumoylation are two important posttranslational modifications in cells. RING (Really Interesting New Gene)-type E3 ligases play essential roles in regulating a plethora of biological processes such as cell survival and death. In our previous study, we performed a microarray using inputs from MN9D dopaminergic neuronal cells treated with 6-hydroxydopamine and identified a novel RING-type E3 ligase, RNF166. We showed that RNF166 exerts proapoptotic effects via ubiquitin-dependent degradation of X-linked inhibitor of apoptosis and subsequent overactivation of caspase-dependent neuronal death following 6-hydroxydopamine treatment. In the present study, we further expanded the list of RNF166's binding substrates using mass spectral analyses of immunoprecipitates obtained from RNF166-overexpressing HEK293 cells. Poly (ADP-ribose) polymerase 1, ATPase WRNIP1, X-ray repair cross-complementing protein 5 (Ku80), and replication protein A 70 were identified as potential binding partners of RNF166. Additionally, we confirmed that RNF166 interacts with and forms lysine 63-linked polyubiquitin chains in Ku80. Consequently, these events promoted the increased stability of Ku80. Intriguingly, we found that RNF166 also contains distinct consensus sequences termed SUMO-interacting motifs and interacts with apoptosis signal-regulating kinase 1 (ASK1). We determined that RNF166 induces the sumoylation of ASK1. Overall, our data provide novel evidence that RNF166 has a dual function of Lys63-linked ubiquitination and sumoylation of its cellular targets.
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11
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Abstract
Cells possess multiple DNA repair pathways to tackle a variety of DNA lesions. Often, DNA repair proteins function as large protein complexes. Here, we describe a protocol to purify DNA repair protein complexes from nuclei of mammalian cells. The method permits purification of protein complexes containing stable as well as transiently associated proteins, which subsequently can be identified by mass-spectrometry analysis. This protocol can be applied to uncover the functions and mechanism of DNA repair pathways. For complete information on the use and execution of this protocol, please refer to Socha et al. (2020).
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