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Luo H, Lao L, Au KS, Northrup H, He X, Forget D, Gauthier MS, Coulombe B, Bourdeau I, Shi W, Gagliardi L, Fragoso MCBV, Peng J, Wu J. ARMC5 controls the degradation of most Pol II subunits, and ARMC5 mutation increases neural tube defect risks in mice and humans. Genome Biol 2024; 25:19. [PMID: 38225631 PMCID: PMC10789052 DOI: 10.1186/s13059-023-03147-w] [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: 04/19/2023] [Accepted: 12/18/2023] [Indexed: 01/17/2024] Open
Abstract
BACKGROUND Neural tube defects (NTDs) are caused by genetic and environmental factors. ARMC5 is part of a novel ubiquitin ligase specific for POLR2A, the largest subunit of RNA polymerase II (Pol II). RESULTS We find that ARMC5 knockout mice have increased incidence of NTDs, such as spina bifida and exencephaly. Surprisingly, the absence of ARMC5 causes the accumulation of not only POLR2A but also most of the other 11 Pol II subunits, indicating that the degradation of the whole Pol II complex is compromised. The enlarged Pol II pool does not lead to generalized Pol II stalling or a generalized decrease in mRNA transcription. In neural progenitor cells, ARMC5 knockout only dysregulates 106 genes, some of which are known to be involved in neural tube development. FOLH1, critical in folate uptake and hence neural tube development, is downregulated in the knockout intestine. We also identify nine deleterious mutations in the ARMC5 gene in 511 patients with myelomeningocele, a severe form of spina bifida. These mutations impair the interaction between ARMC5 and Pol II and reduce Pol II ubiquitination. CONCLUSIONS Mutations in ARMC5 increase the risk of NTDs in mice and humans. ARMC5 is part of an E3 controlling the degradation of all 12 subunits of Pol II under physiological conditions. The Pol II pool size might have effects on NTD pathogenesis, and some of the effects might be via the downregulation of FOLH1. Additional mechanistic work is needed to establish the causal effect of the findings on NTD pathogenesis.
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Affiliation(s)
- Hongyu Luo
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada.
| | - Linjiang Lao
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Kit Sing Au
- Department of Pediatrics, McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth) and Children's Memorial Hermann Hospital, Houston, TX, USA
| | - Hope Northrup
- Department of Pediatrics, McGovern Medical School at the University of Texas Health Science Center at Houston (UTHealth) and Children's Memorial Hermann Hospital, Houston, TX, USA
| | - Xiao He
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Diane Forget
- Department of Translational Proteomics, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Marie-Soleil Gauthier
- Department of Translational Proteomics, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Benoit Coulombe
- Department of Translational Proteomics, Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, QC, Canada
| | - Isabelle Bourdeau
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
- Division of Endocrinology, CHUM, Montreal, QC, Canada
- Department of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Wei Shi
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Lucia Gagliardi
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
- Department of Genetics and Molecular Pathology, SA Pathology, Adelaide, Australia
- Endocrine and Diabetes Unit, Queen Elizabeth Hospital, Adelaide, Australia
| | - Maria Candida Barisson Villares Fragoso
- Unidade de Suprarrenal Disciplina de Endocrinologia E Metabologia, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Junzheng Peng
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Jiangping Wu
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, QC, Canada.
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.
- Division of Nephrology, CHUM, Montreal, QC, Canada.
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Kim SJ, Maric C, Briu LM, Fauchereau F, Baldacci G, Debatisse M, Koundrioukoff S, Cadoret JC. Firing of Replication Origins Is Disturbed by a CDK4/6 Inhibitor in a pRb-Independent Manner. Int J Mol Sci 2023; 24:10629. [PMID: 37445805 DOI: 10.3390/ijms241310629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/21/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Over the last decade, CDK4/6 inhibitors (palbociclib, ribociclib and abemaciclib) have emerged as promising anticancer drugs. Numerous studies have demonstrated that CDK4/6 inhibitors efficiently block the pRb-E2F pathway and induce cell cycle arrest in pRb-proficient cells. Based on these studies, the inhibitors have been approved by the FDA for treatment of advanced hormonal receptor (HR) positive breast cancers in combination with hormonal therapy. However, some evidence has recently shown unexpected effects of the inhibitors, underlining a need to characterize the effects of CDK4/6 inhibitors beyond pRb. Our study demonstrates how palbociclib impairs origin firing in the DNA replication process in pRb-deficient cell lines. Strikingly, despite the absence of pRb, cells treated with palbociclib synthesize less DNA while showing no cell cycle arrest. Furthermore, this CDK4/6 inhibitor treatment disturbs the temporal program of DNA replication and reduces the density of replication forks. Cells treated with palbociclib show a defect in the loading of the Pre-initiation complex (Pre-IC) proteins on chromatin, indicating a reduced initiation of DNA replication. Our findings highlight hidden effects of palbociclib on the dynamics of DNA replication and of its cytotoxic consequences on cell viability in the absence of pRb. This study provides a potential therapeutic application of palbociclib in combination with other drugs to target genomic instability in pRB-deficient cancers.
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Affiliation(s)
- Su-Jung Kim
- CNRS, Institut Jacques Monod, Université Paris Cité, F-75013 Paris, France
- CNRS UMR9019, Institut Gustave Roussy, 94805 Villejuif, France
| | - Chrystelle Maric
- CNRS, Institut Jacques Monod, Université Paris Cité, F-75013 Paris, France
| | - Lina-Marie Briu
- CNRS, Institut Jacques Monod, Université Paris Cité, F-75013 Paris, France
| | - Fabien Fauchereau
- CNRS, Institut Jacques Monod, Université Paris Cité, F-75013 Paris, France
| | - Giuseppe Baldacci
- CNRS, Institut Jacques Monod, Université Paris Cité, F-75013 Paris, France
| | - Michelle Debatisse
- CNRS UMR9019, Institut Gustave Roussy, 94805 Villejuif, France
- Sorbonne Université, 75005 Paris, France
| | - Stéphane Koundrioukoff
- CNRS UMR9019, Institut Gustave Roussy, 94805 Villejuif, France
- Sorbonne Université, 75005 Paris, France
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Gielecińska A, Kciuk M, Mujwar S, Celik I, Kołat D, Kałuzińska-Kołat Ż, Kontek R. Substances of Natural Origin in Medicine: Plants vs. Cancer. Cells 2023; 12:986. [PMID: 37048059 PMCID: PMC10092955 DOI: 10.3390/cells12070986] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/14/2023] [Accepted: 03/20/2023] [Indexed: 04/14/2023] Open
Abstract
Continuous monitoring of the population's health is the main method of learning about disease prevalence. National and international data draw attention to the persistently high rates of cancer incidence. This necessitates the intensification of efforts aimed at developing new, more effective chemotherapeutic and chemopreventive drugs. Plants represent an invaluable source of natural substances with versatile medicinal properties. Multidirectional activities exhibited by natural substances and their ability to modulate key signaling pathways, mainly related to cancer cell death, make these substances an important research direction. This review summarizes the information regarding plant-derived chemotherapeutic drugs, including their mechanisms of action, with a special focus on selected anti-cancer drugs (paclitaxel, irinotecan) approved in clinical practice. It also presents promising plant-based drug candidates currently being tested in clinical and preclinical trials (betulinic acid, resveratrol, and roburic acid).
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Affiliation(s)
- Adrianna Gielecińska
- Doctoral School of Exact and Natural Sciences, University of Lodz, 90-237 Lodz, Poland
- Department of Molecular Biotechnology and Genetics, University of Lodz, 90-237 Lodz, Poland
| | - Mateusz Kciuk
- Doctoral School of Exact and Natural Sciences, University of Lodz, 90-237 Lodz, Poland
- Department of Molecular Biotechnology and Genetics, University of Lodz, 90-237 Lodz, Poland
| | - Somdutt Mujwar
- Chitkara College of Pharmacy, Chitkara University, Rajpura 140401, Punjab, India
| | - Ismail Celik
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri 38039, Turkey
| | - Damian Kołat
- Department of Experimental Surgery, Faculty of Medicine, Medical University of Lodz, Narutowicza 60, 90-136 Lodz, Poland
| | - Żaneta Kałuzińska-Kołat
- Department of Experimental Surgery, Faculty of Medicine, Medical University of Lodz, Narutowicza 60, 90-136 Lodz, Poland
| | - Renata Kontek
- Department of Molecular Biotechnology and Genetics, University of Lodz, 90-237 Lodz, Poland
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Ticli G, Cazzalini O, Stivala LA, Prosperi E. Revisiting the Function of p21CDKN1A in DNA Repair: The Influence of Protein Interactions and Stability. Int J Mol Sci 2022; 23:ijms23137058. [PMID: 35806061 PMCID: PMC9267019 DOI: 10.3390/ijms23137058] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 12/12/2022] Open
Abstract
The p21CDKN1A protein is an important player in the maintenance of genome stability through its function as a cyclin-dependent kinase inhibitor, leading to cell-cycle arrest after genotoxic damage. In the DNA damage response, p21 interacts with specific proteins to integrate cell-cycle arrest with processes such as transcription, apoptosis, DNA repair, and cell motility. By associating with Proliferating Cell Nuclear Antigen (PCNA), the master of DNA replication, p21 is able to inhibit DNA synthesis. However, to avoid conflicts with this process, p21 protein levels are finely regulated by pathways of proteasomal degradation during the S phase, and in all the phases of the cell cycle, after DNA damage. Several lines of evidence have indicated that p21 is required for the efficient repair of different types of genotoxic lesions and, more recently, that p21 regulates DNA replication fork speed. Therefore, whether p21 is an inhibitor, or rather a regulator, of DNA replication and repair needs to be re-evaluated in light of these findings. In this review, we will discuss the lines of evidence describing how p21 is involved in DNA repair and will focus on the influence of protein interactions and p21 stability on the efficiency of DNA repair mechanisms.
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Affiliation(s)
- Giulio Ticli
- Istituto di Genetica Molecolare “Luigi Luca Cavalli-Sforza”, Consiglio Nazionale delle Ricerche (CNR), Via Abbiategrasso 207, 27100 Pavia, Italy;
- Dipartimento di Biologia e Biotecnologie, Università di Pavia, Via Ferrata 9, 27100 Pavia, Italy
| | - Ornella Cazzalini
- Dipartimento di Medicina Molecolare, Università di Pavia, Via Ferrata 9, 27100 Pavia, Italy; (O.C.); (L.A.S.)
| | - Lucia A. Stivala
- Dipartimento di Medicina Molecolare, Università di Pavia, Via Ferrata 9, 27100 Pavia, Italy; (O.C.); (L.A.S.)
| | - Ennio Prosperi
- Istituto di Genetica Molecolare “Luigi Luca Cavalli-Sforza”, Consiglio Nazionale delle Ricerche (CNR), Via Abbiategrasso 207, 27100 Pavia, Italy;
- Correspondence: ; Tel.: +39-0382-986267
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Chang S, Zhu Y, Xi Y, Gao F, Lu J, Dong L, Ma C, Li H. High DSCC1 Level Predicts Poor Prognosis of Lung Adenocarcinoma. Int J Gen Med 2021; 14:6961-6974. [PMID: 34707388 PMCID: PMC8542575 DOI: 10.2147/ijgm.s329482] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/20/2021] [Indexed: 12/04/2022] Open
Abstract
Purpose To evaluate the role of DSCC1 in LUAD. Patients and Methods Based on TCGA and GTEx, the Wilcoxon rank-sum test was used to compare the expression differences of DSCC1 between the normal samples of GTEx combined TCGA and the unpaired tumor samples of TCGA, and to compare DSCC1 expression values between tumor tissues and paired normal LUAD tissues in the TCGA cohort. Kruskal–Wallis rank-sum test, Wilcoxon rank-sum test, and logistics regression were used to compare the relationship between the expression of DSCC1 and the clinicopathological parameters. The biological function of DSCC1 was annotated by GSEA and ssGSEA, while Kaplan–Meier and Cox regression analysis were used to evaluate the prognostic value of DSCC1. Furthermore, the time-dependent ROC curve was used to analyze the diagnostic efficacy of DSCC1 in LUAD. Results We downloaded the RNA-Seq data of 513 LUAD cases. The expression of DSCC1 was significantly correlated with T stage (OR = 1.04(1.02–1.07), P = 0.002), pathological stage (OR=1.03 (1.01–1.05), P = 0.008) and TP53 status (OR=1.10 (1.07–1.14), P < 0.001). The high expression of DSCC1 was significantly correlated with DSS (HR=1.56 (1.07–2.26), P = 0.021) and OS (HR=1.53 (1.14–2.05), P = 0.004). Moreover, ROC curve analysis (AUC=0.845, CI (0.820-0.870)) indicated DSCC1 as a potential diagnostic molecule for LUAD. In the group with high DSCC1 expression phenotype, down-regulation of EGFR signal, reduction of IL-6 deprivation, cell cycle, and p53 signal pathway were significantly abundant. Spearman correlation analysis showed that the expression of DSCC1 was positively correlated with the infiltration of Th2 cells, T Helper cells. Conclusion Our results suggest that DSCC1 may be an important biomarker for the treatment of LUAD.
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Affiliation(s)
- Sisi Chang
- Department of Oncology, Henan Provincial Hospital of Traditional Chinese Medicine (The Second Affiliated Hospital of Henan University of Traditional Chinese Medicine), Zhengzhou, Henan Province, People's Republic of China
| | - Yahui Zhu
- Department of Oncology, Henan University of Traditional Chinese Medicine, Zhengzhou, Henan Province, People's Republic of China
| | - Yutan Xi
- Department of Oncology, Henan University of Traditional Chinese Medicine, Zhengzhou, Henan Province, People's Republic of China
| | - Fuyan Gao
- Department of Oncology, Henan University of Traditional Chinese Medicine, Zhengzhou, Henan Province, People's Republic of China
| | - Juanjuan Lu
- Department of Oncology, Henan University of Traditional Chinese Medicine, Zhengzhou, Henan Province, People's Republic of China
| | - Liang Dong
- Department of Oncology, Henan Provincial Hospital of Traditional Chinese Medicine (The Second Affiliated Hospital of Henan University of Traditional Chinese Medicine), Zhengzhou, Henan Province, People's Republic of China
| | - Chunzheng Ma
- Department of Oncology, Henan Provincial Hospital of Traditional Chinese Medicine (The Second Affiliated Hospital of Henan University of Traditional Chinese Medicine), Zhengzhou, Henan Province, People's Republic of China
| | - Honglin Li
- Department of Oncology, Henan Provincial Hospital of Traditional Chinese Medicine (The Second Affiliated Hospital of Henan University of Traditional Chinese Medicine), Zhengzhou, Henan Province, People's Republic of China
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Kuang Y, Kang J, Li H, Liu B, Zhao X, Li L, Jin X, Li Q. Multiple functions of p21 in cancer radiotherapy. J Cancer Res Clin Oncol 2021; 147:987-1006. [PMID: 33547489 DOI: 10.1007/s00432-021-03529-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/10/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Greater than half of cancer patients experience radiation therapy, for both radical and palliative objectives. It is well known that researches on radiation response mechanisms are conducive to improve the efficacy of cancer radiotherapy. p21 was initially identified as a widespread inhibitor of cyclin-dependent kinases, transcriptionally modulated by p53 and a marker of cellular senescence. It was once considered that p21 acts as a tumour suppressor mainly to restrain cell cycle progression, thereby resulting in growth suppression. With the deepening researches on p21, p21 has been found to regulate radiation responses via participating in multiple cellular processes, including cell cycle arrest, apoptosis, DNA repair, senescence and autophagy. Hence, a comprehensive summary of the p21's functions in radiation response will provide a new perspective for radiotherapy against cancer. METHODS We summarize the recent pertinent literature from various electronic databases, including PubMed and analyzed several datasets from Gene Expression Omnibus database. This review discusses how p21 influences the effect of cancer radiotherapy via involving in multiple signaling pathways and expounds the feasibility, barrier and risks of using p21 as a biomarker as well as a therapeutic target of radiotherapy. CONCLUSION p21's complicated and important functions in cancer radiotherapy make it a promising therapeutic target. Besides, more thorough insights of p21 are needed to make it a safe therapeutic target.
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Affiliation(s)
- Yanbei Kuang
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian Kang
- College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
| | - Hongbin Li
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
| | - Bingtao Liu
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xueshan Zhao
- The First Hospital of Lanzhou University, Lanzhou, 730000, China
| | - Linying Li
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, 730000, China
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Lanzhou, 730000, Gansu, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaodong Jin
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China.
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, 730000, China.
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Lanzhou, 730000, Gansu, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Qiang Li
- Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou, 730000, Gansu, China.
- Key Laboratory of Heavy Ion Radiation Biology and Medicine, Chinese Academy of Sciences, Lanzhou, 730000, China.
- Key Laboratory of Basic Research on Heavy Ion Radiation Application in Medicine, Lanzhou, 730000, Gansu, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Wang L, Han H, Dong L, Wang Z, Qin Y. Function of p21 and its therapeutic effects in esophageal cancer. Oncol Lett 2020; 21:136. [PMID: 33552255 PMCID: PMC7798030 DOI: 10.3892/ol.2020.12397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/25/2020] [Indexed: 12/24/2022] Open
Abstract
Esophageal cancer (EC) is the eighth most common type of cancer worldwide and ranks sixth among the causes of cancer-related mortality. Due to the high mortality rate and poor treatment efficacy for EC, millions of individuals succumb to this disease; thus, the identification of novel treatment targets is of utmost importance and urgency. In recent years, there have been advances if therapies targeting cell cycle regulators. p21 is a type of cell cycle regulator that plays a dual role in tumor cells, as it can not only regulate the cell cycle, induce apoptosis and inhibit cell proliferation, but can also protect cells from apoptosis. It has been found that p21 often exerts a tumor-suppressive effect on EC, which provides a basis for its use as a treatment target for EC. Therefore, the aim of the present study was to review the function of p21 and its potential value as a therapeutic target for EC.
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Affiliation(s)
- Lei Wang
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Huiqiong Han
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Lin Dong
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Zehua Wang
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Yanru Qin
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
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Woźniak E, Reszka E, Jabłońska E, Mokra K, Balcerczyk A, Huras B, Zakrzewski J, Bukowska B. The selected epigenetic effects of aminomethylphosphonic acid, a primary metabolite of glyphosate on human peripheral blood mononuclear cells (in vitro). Toxicol In Vitro 2020; 66:104878. [PMID: 32360641 DOI: 10.1016/j.tiv.2020.104878] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/18/2020] [Accepted: 04/26/2020] [Indexed: 12/20/2022]
Abstract
Aminomethylphosphonic acid (AMPA) is a primary metabolite of glyphosate and amino-polyphosphonate. We have determined the effect of AMPA on selected epigenetic parameters and major cell cycle drivers in human peripheral blood mononuclear cells (PBMCs). The cells were incubated with AMPA at 0.5, 10 and 250 μM for 24 h. The performed analysis included: global DNA methylation by colorimetric measurement of 5-methylcytosine in DNA, methylation in the promoter regions of selected tumor suppressor genes (P16, P21, TP53) and proto-oncogenes (BCL2, CCND1) as well as the expression profile of the indicated genes by Real-Time PCR assays. The obtained results have revealed significant reduction of global DNA methylation level in PBMCs exposed to AMPA. Investigated xenobiotic changed methylation pattern of the P21 and TP53 suppressor gene promoters, but in case of other analyzed genes: P16, BCL2 and CCND1 no statistically significant changes have been noted. Gene profiling have shown that AMPA only changed the expression of CCND1. Summing up, our results have revealed a small potential disturbance in methylation processes and the absence of changes in expression of tested tumor suppressor genes (P16, P21, TP53) and protooncogenes (BCL2) in human PBMCs exposed to AMPA.
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Affiliation(s)
- Ewelina Woźniak
- University of Lodz, Faculty of Biology and Environmental Protection, Department of Biophysics of Environmental Pollution, Pomorska Str. 141/143, 90-236 Lodz, Poland; Medical University of Lodz, Department of Internal Diseases and Clinical Pharmacology, Laboratory of Tissue Immunopharmacology, Kniaziewicza Str. 1/5, 91-347 Lodz, Poland
| | - Edyta Reszka
- Nofer Institute of Occupational Medicine, Department of Molecular Genetics and Epigenetics, Teresy Str. 8, 91-348 Lodz, Poland
| | - Ewa Jabłońska
- Nofer Institute of Occupational Medicine, Department of Molecular Genetics and Epigenetics, Teresy Str. 8, 91-348 Lodz, Poland
| | - Katarzyna Mokra
- University of Lodz, Faculty of Biology and Environmental Protection, Department of Biophysics of Environmental Pollution, Pomorska Str. 141/143, 90-236 Lodz, Poland
| | - Aneta Balcerczyk
- University of Lodz, Faculty of Biology and Environmental Protection, Department of Molecular Biophysics, Pomorska Str. 141/143, 90-236 Lodz, Poland
| | - Bogumiła Huras
- Łukasiewicz Research Network, Institute of Industrial Organic Chemistry, Annopol 6 Str, 03-236 Warsaw, Poland
| | - Jerzy Zakrzewski
- Łukasiewicz Research Network, Institute of Industrial Organic Chemistry, Annopol 6 Str, 03-236 Warsaw, Poland
| | - Bożena Bukowska
- University of Lodz, Faculty of Biology and Environmental Protection, Department of Biophysics of Environmental Pollution, Pomorska Str. 141/143, 90-236 Lodz, Poland.
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Mansilla SF, De La Vega MB, Calzetta NL, Siri SO, Gottifredi V. CDK-Independent and PCNA-Dependent Functions of p21 in DNA Replication. Genes (Basel) 2020; 11:genes11060593. [PMID: 32481484 PMCID: PMC7349641 DOI: 10.3390/genes11060593] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 12/12/2022] Open
Abstract
p21Waf/CIP1 is a small unstructured protein that binds and inactivates cyclin-dependent kinases (CDKs). To this end, p21 levels increase following the activation of the p53 tumor suppressor. CDK inhibition by p21 triggers cell-cycle arrest in the G1 and G2 phases of the cell cycle. In the absence of exogenous insults causing replication stress, only residual p21 levels are prevalent that are insufficient to inhibit CDKs. However, research from different laboratories has demonstrated that these residual p21 levels in the S phase control DNA replication speed and origin firing to preserve genomic stability. Such an S-phase function of p21 depends fully on its ability to displace partners from chromatin-bound proliferating cell nuclear antigen (PCNA). Vice versa, PCNA also regulates p21 by preventing its upregulation in the S phase, even in the context of robust p21 induction by irradiation. Such a tight regulation of p21 in the S phase unveils the potential that CDK-independent functions of p21 may have for the improvement of cancer treatments.
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Kreis NN, Louwen F, Yuan J. The Multifaceted p21 (Cip1/Waf1/ CDKN1A) in Cell Differentiation, Migration and Cancer Therapy. Cancers (Basel) 2019; 11:cancers11091220. [PMID: 31438587 PMCID: PMC6770903 DOI: 10.3390/cancers11091220] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/15/2019] [Accepted: 08/17/2019] [Indexed: 12/12/2022] Open
Abstract
Loss of cell cycle control is characteristic of tumorigenesis. The protein p21 is the founding member of cyclin-dependent kinase inhibitors and an important versatile cell cycle protein. p21 is transcriptionally controlled by p53 and p53-independent pathways. Its expression is increased in response to various intra- and extracellular stimuli to arrest the cell cycle ensuring genomic stability. Apart from its roles in cell cycle regulation including mitosis, p21 is involved in differentiation, cell migration, cytoskeletal dynamics, apoptosis, transcription, DNA repair, reprogramming of induced pluripotent stem cells, autophagy and the onset of senescence. p21 acts either as a tumor suppressor or as an oncogene depending largely on the cellular context, its subcellular localization and posttranslational modifications. In the present review, we briefly mention the general functions of p21 and summarize its roles in differentiation, migration and invasion in detail. Finally, regarding its dual role as tumor suppressor and oncogene, we highlight the potential, difficulties and risks of using p21 as a biomarker as well as a therapeutic target.
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Affiliation(s)
- Nina-Naomi Kreis
- Department of Gynecology and Obstetrics, University Hospital, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany.
| | - Frank Louwen
- Department of Gynecology and Obstetrics, University Hospital, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
| | - Juping Yuan
- Department of Gynecology and Obstetrics, University Hospital, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
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11
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Perumal SK, Xu X, Yan C, Ivanov I, Benkovic SJ. Recognition of a Key Anchor Residue by a Conserved Hydrophobic Pocket Ensures Subunit Interface Integrity in DNA Clamps. J Mol Biol 2019; 431:2493-2510. [PMID: 31051173 DOI: 10.1016/j.jmb.2019.04.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 04/22/2019] [Accepted: 04/22/2019] [Indexed: 10/26/2022]
Abstract
Sliding clamp proteins encircle duplex DNA and are involved in processive DNA replication and the DNA damage response. Clamp proteins are ring-shaped oligomers (dimers or trimers) and are loaded onto DNA by an ATP-dependent clamp loader complex that ruptures the interface between two adjacent subunits. Here we measured the solution dynamics of the human clamp protein, proliferating cell nuclear antigen, by monitoring the change in the fluorescence of a site-specifically labeled. To unravel the origins of clamp subunit interface stability, we carried out comprehensive comparative analysis of the interfaces of seven sliding clamps. We used computational modeling (molecular dynamic simulations and MM/GBSA binding energy decomposition analyses) to identify conserved networks of hydrophobic residues critical for clamp stability and ring-opening dynamics. The hydrophobic network is shared among clamp proteins and exhibits a "key in a keyhole" pattern where a bulky aromatic residue from one clamp subunit is anchored into a hydrophobic pocket of the opposing subunit. Bioinformatics and dynamic network analyses showed that this oligomeric latch is conserved across DNA sliding clamps from all domains of life and dictates the dynamics of clamp opening and closing.
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Affiliation(s)
- Senthil K Perumal
- Department of Chemistry, 414 Wartik Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xiaojun Xu
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302, USA
| | - Chunli Yan
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302, USA
| | - Ivaylo Ivanov
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302, USA.
| | - Stephen J Benkovic
- Department of Chemistry, 414 Wartik Laboratory, The Pennsylvania State University, University Park, PA 16802, USA.
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12
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Asghari MH, Moloudizargari M, Ghobadi E, Fallah M, Abdollahi M. Melatonin as a multifunctional anti-cancer molecule: Implications in gastric cancer. Life Sci 2017; 185:38-45. [DOI: 10.1016/j.lfs.2017.07.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 07/14/2017] [Accepted: 07/20/2017] [Indexed: 12/13/2022]
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13
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Smith SJ, Hickey RJ, Malkas LH. Validating the disruption of proliferating cell nuclear antigen interactions in the development of targeted cancer therapeutics. Cancer Biol Ther 2016; 17:310-9. [PMID: 26889573 DOI: 10.1080/15384047.2016.1139247] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Human DNA replication and repair is a highly coordinated process involving the specifically timed actions of numerous proteins and enzymes. Many of these proteins require interaction with proliferating cell nuclear antigen (PCNA) for activation within the process. The interdomain connector loop (IDCL) of PCNA provides a docking site for many of those proteins, suggesting that this region is critically important in the regulation of cellular function. Previous work in this laboratory has demonstrated that a peptide mimicking a specific region of the IDCL (caPeptide) has the ability to disrupt key protein-protein interactions between PCNA and its binding partners, thereby inhibiting DNA replication within the cells. In this study, we confirm the ability of the caPeptide to disrupt DNA replication function using both intact cell and in vitro DNA replication assays. Further, we were able to demonstrate that treatment with caPeptide results in a decrease of polymerase δ activity that correlates with the observed decrease in DNA replication. We have also successfully developed a surface plasmon resonance (SPR) assay to validate the disruption of the PCNA-pol δ interaction with caPeptide.
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Affiliation(s)
- Shanna J Smith
- a Beckman Research Institute at City of Hope , Department of Molecular and Cellular Biology , Duarte , CA , USA
| | - Robert J Hickey
- b Beckman Research Institute at City of Hope , Department of Molecular Pharmacology , Duarte , CA , USA
| | - Linda H Malkas
- a Beckman Research Institute at City of Hope , Department of Molecular and Cellular Biology , Duarte , CA , USA
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14
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Cao R, Zhang J, Zhang M, Chen X. PPM1D regulates p21 expression via dephoshporylation at serine 123. Cell Cycle 2015; 14:641-7. [PMID: 25590690 DOI: 10.4161/15384101.2014.994922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The cyclin-dependent kinase inhibitor p21 plays a critical role in regulating cell cycle and cell proliferation. We previously cloned the dog p21 gene and found that unlike human p21, dog p21 is expressed as 2 isoforms due to the proline-directed phosphorylation at serine 123 (S123). Here, we identified that PPM1D, also called Wip1 and a Mg(2+)-dependent phosphatase, dephosphorylates dog p21 protein at serine 123. Specifically, we showed that the level of S123-phosphorylated dog p21 is increased by a PPM1D inhibitor in a dose-dependent manner. We also showed that over-expression of PPM1D decreases, whereas knockdown of PPM1D increases, the level of S123-phosphorylated dog p21 regardless of p53. Additionally, in vitro phosphatase assay was performed and showed that phosphorylated S123 in dog p21 is dephosphorylated by recombinant rPPM1D, which contains the catalytic domain of human PPM1D (residue 1-420), but not by the phosphatase dead rPPM1D (D314A). Furthermore, dephosphorylation of S123 by rPPM1D can be abrogated by PPM1D inhibitor or by withdrawal of Mg(2+). Finally, we showed that upon PPM1D inhibition, the level of S123-phosphorylated dog p21 was increased, concomitantly with decreased expression of cyclin A, cyclin B, Rb, and PCNA. Together, our results indicate that PPM1D functions as a phosphatase of dog p21 at serine 123 and plays a role in cell cycle control via p21.
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Affiliation(s)
- Ruibing Cao
- a College of Veterinary Medicine; Nanjing Agricultural University ; Nanjing , China
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15
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Ngo GHP, Balakrishnan L, Dubarry M, Campbell JL, Lydall D. The 9-1-1 checkpoint clamp stimulates DNA resection by Dna2-Sgs1 and Exo1. Nucleic Acids Res 2014; 42:10516-28. [PMID: 25122752 PMCID: PMC4176354 DOI: 10.1093/nar/gku746] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Single-stranded DNA (ssDNA) at DNA ends is an important regulator of the DNA damage response. Resection, the generation of ssDNA, affects DNA damage checkpoint activation, DNA repair pathway choice, ssDNA-associated mutation and replication fork stability. In eukaryotes, extensive DNA resection requires the nuclease Exo1 and nuclease/helicase pair: Dna2 and Sgs1BLM. How Exo1 and Dna2-Sgs1BLM coordinate during resection remains poorly understood. The DNA damage checkpoint clamp (the 9-1-1 complex) has been reported to play an important role in stimulating resection but the exact mechanism remains unclear. Here we show that the human 9-1-1 complex enhances the cleavage of DNA by both DNA2 and EXO1 in vitro, showing that the resection-stimulatory role of the 9-1-1 complex is direct. We also show that in Saccharomyces cerevisiae, the 9-1-1 complex promotes both Dna2-Sgs1 and Exo1-dependent resection in response to uncapped telomeres. Our results suggest that the 9-1-1 complex facilitates resection by recruiting both Dna2-Sgs1 and Exo1 to sites of resection. This activity of the 9-1-1 complex in supporting resection is strongly inhibited by the checkpoint adaptor Rad953BP1. Our results provide important mechanistic insights into how DNA resection is regulated by checkpoint proteins and have implications for genome stability in eukaryotes.
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Affiliation(s)
- Greg H P Ngo
- Institute for Cell and Molecular Biosciences (ICaMB), Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Lata Balakrishnan
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Marion Dubarry
- Institute for Cell and Molecular Biosciences (ICaMB), Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Judith L Campbell
- Divisions of Biology and Chemistry, Caltech, Braun Laboratories, Pasadena, CA 91125, USA
| | - David Lydall
- Institute for Cell and Molecular Biosciences (ICaMB), Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
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16
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Akhter N, Akhtar MS, Ahmad MM, Haque S, Siddiqui S, Hasan SI, Shukla NK, Husain SA. Association of mutation and hypermethylation of p21 gene with susceptibility to breast cancer: a study from north India. Mol Biol Rep 2014; 41:2999-3007. [DOI: 10.1007/s11033-014-3159-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 01/13/2014] [Indexed: 12/30/2022]
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17
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Resveratrol mediated cell death in cigarette smoke transformed breast epithelial cells is through induction of p21Waf1/Cip1 and inhibition of long patch base excision repair pathway. Toxicol Appl Pharmacol 2014; 275:221-31. [PMID: 24467951 DOI: 10.1016/j.taap.2014.01.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 12/20/2013] [Accepted: 01/14/2014] [Indexed: 12/30/2022]
Abstract
Cigarette smoking is a key factor for the development and progression of different cancers including mammary tumor in women. Resveratrol (Res) is a promising natural chemotherapeutic agent that regulates many cellular targets including p21, a cip/kip family of cyclin kinase inhibitors involved in DNA damage-induced cell cycle arrest and blocking of DNA replication and repair. We have recently shown that cigarette smoke condensate (CSC) prepared from commercially available Indian cigarette can cause neoplastic transformation of normal breast epithelial MCF-10A cell. Here we studied the mechanism of Res mediated apoptosis in CSC transformed (MCF-10A-Tr) cells in vitro and in vivo. Res mediated apoptosis in MCF-10A-Tr cells was a p21 dependent event. It increased the p21 protein expression in MCF-10A-Tr cells and MCF-10A-Tr cells-mediated tumors in xenograft mice. Res treatment reduced the tumor size(s) and expression of anti-apoptotic proteins (e.g. PI3K, AKT, NFκB) in solid tumor. The expressions of cell cycle regulatory (Cyclins, CDC-2, CDC-6, etc.), BER associated (Pol-β, Pol-δ, Pol-ε, Pol-η, RPA, Fen-1, DNA-Ligase-I, etc.) proteins and LP-BER activity decreased in MCF-10A-Tr cells but remain significantly unaltered in isogenic p21 null MCF-10A-Tr cells after Res treatment. Interestingly, no significant changes were noted in SP-BER activity in both the cell lines after Res exposure. Finally, it was observed that increased p21 blocks the LP-BER in MCF-10A-Tr cells by increasing its interaction with PCNA via competing with Fen-1 after Res treatment. Thus, Res caused apoptosis in CSC-induced cancer cells by reduction of LP-BER activity and this phenomenon largely depends on p21.
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18
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Yao H, Sundar IK, Gorbunova V, Rahman I. P21-PARP-1 pathway is involved in cigarette smoke-induced lung DNA damage and cellular senescence. PLoS One 2013; 8:e80007. [PMID: 24244594 PMCID: PMC3823706 DOI: 10.1371/journal.pone.0080007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 10/07/2013] [Indexed: 12/20/2022] Open
Abstract
Persistent DNA damage triggers cellular senescence, which may play an important role in the pathogenesis of cigarette smoke (CS)-induced lung diseases. Both p21CDKN1A (p21) and poly(ADP-ribose) polymerase-1 (PARP-1) are involved in DNA damage and repair. However, the role of p21-PARP-1 axis in regulating CS-induced lung DNA damage and cellular senescence remains unknown. We hypothesized that CS causes DNA damage and cellular senescence through a p21-PARP-1 axis. To test this hypothesis, we determined the levels of γH2AX (a marker for DNA double-strand breaks) as well as non-homologous end joining proteins (Ku70 and Ku80) in lungs of mice exposed to CS. We found that the level of γH2AX was increased, whereas the level of Ku70 was reduced in lungs of CS-exposed mice. Furthermore, p21 deletion reduced the level of γH2AX, but augmented the levels of Ku70, Ku80, and PAR in lungs by CS. Administration of PARP-1 inhibitor 3-aminobenzamide increased CS-induced DNA damage, but lowered the levels of Ku70 and Ku80, in lungs of p21 knockout mice. Moreover, 3-aminobenzamide increased senescence-associated β-galactosidase activity, but decreased the expression of proliferating cell nuclear antigen in mouse lungs in response to CS. Interestingly, 3-aminobenzamide treatment had no effect on neutrophil influx into bronchoalveolar lavage fluid by CS. These results demonstrate that the p21-PARP-1 pathway is involved in CS-induced DNA damage and cellular senescence.
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Affiliation(s)
- Hongwei Yao
- Department of Environmental Medicine, Lung Biology and Disease Program, Rochester, New York, United States of America
- * E-mail: (HY); (IR)
| | - Isaac K. Sundar
- Department of Environmental Medicine, Lung Biology and Disease Program, Rochester, New York, United States of America
| | - Vera Gorbunova
- Department of Biology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Irfan Rahman
- Department of Environmental Medicine, Lung Biology and Disease Program, Rochester, New York, United States of America
- * E-mail: (HY); (IR)
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19
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Cazzalini O, Perucca P, Mocchi R, Sommatis S, Prosperi E, Stivala LA. DDB2 association with PCNA is required for its degradation after UV-induced DNA damage. Cell Cycle 2013; 13:240-8. [PMID: 24200966 PMCID: PMC3906241 DOI: 10.4161/cc.26987] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 10/23/2013] [Accepted: 10/29/2013] [Indexed: 12/23/2022] Open
Abstract
DDB2 is a protein playing an essential role in the lesion recognition step of the global genome sub-pathway of nucleotide excision repair (GG-NER) process. Among the proteins involved in the DNA damage response, p21(CDKN1A) (p21) has been reported to participate in NER, but also to be removed by proteolytic degradation, thanks to its association with PCNA. DDB2 is involved in the CUL4-DDB1 complex mediating p21 degradation; however, the direct interaction between DDB2, p21 and PCNA has been never investigated. Here, we show that DDB2 co-localizes with PCNA and p21 at local UV-induced DNA-damage sites, and these proteins co-immunoprecipitate in the same complex. In addition, we provide evidence that p21 is not able to bind directly DDB2, but, to this end, the presence of PCNA is required. Direct physical association of recombinant DDB2 protein with PCNA is mediated by a conserved PIP-box present in the N-terminal region of DDB2. Mutation of the PIP-box resulted in the loss of protein interaction. Interestingly, the same mutation, or depletion of PCNA by RNA interference, greatly impaired DDB2 degradation induced by UV irradiation. These results indicate that DDB2 is a PCNA-binding protein, and that this association is required for DDB2 proteolytic degradation.
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Affiliation(s)
- Ornella Cazzalini
- Dipartimento di Medicina Molecolare; Unità di Immunologia e Patologia Generale; Università di Pavia; Pavia, Italy
| | - Paola Perucca
- Dipartimento di Medicina Molecolare; Unità di Immunologia e Patologia Generale; Università di Pavia; Pavia, Italy
| | - Roberto Mocchi
- Dipartimento di Medicina Molecolare; Unità di Immunologia e Patologia Generale; Università di Pavia; Pavia, Italy
| | - Sabrina Sommatis
- Dipartimento di Medicina Molecolare; Unità di Immunologia e Patologia Generale; Università di Pavia; Pavia, Italy
| | - Ennio Prosperi
- Istituto di Genetica Molecolare (IGM) del CNR; Pavia, Italy
| | - Lucia Anna Stivala
- Dipartimento di Medicina Molecolare; Unità di Immunologia e Patologia Generale; Università di Pavia; Pavia, Italy
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20
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Mansilla SF, Soria G, Vallerga MB, Habif M, Martínez-López W, Prives C, Gottifredi V. UV-triggered p21 degradation facilitates damaged-DNA replication and preserves genomic stability. Nucleic Acids Res 2013; 41:6942-51. [PMID: 23723248 PMCID: PMC3737556 DOI: 10.1093/nar/gkt475] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Although many genotoxic treatments upregulate the cyclin kinase inhibitor p21, agents such as UV irradiation trigger p21 degradation. This suggests that p21 blocks a process relevant for the cellular response to UV. Here, we show that forced p21 stabilization after UV strongly impairs damaged-DNA replication, which is associated with permanent deficiencies in the recruitment of DNA polymerases from the Y family involved in translesion DNA synthesis), with the accumulation of DNA damage markers and increased genomic instability. Remarkably, such noxious effects disappear when disrupting the proliferating cell nuclear antigen (PCNA) interacting motif of stable p21, thus suggesting that the release of PCNA from p21 interaction is sufficient to allow the recruitment to PCNA of partners (such as Y polymerases) relevant for the UV response. Expression of degradable p21 only transiently delays early replication events and Y polymerase recruitment after UV irradiation. These temporary defects disappear in a manner that correlates with p21 degradation with no detectable consequences on later replication events or genomic stability. Together, our findings suggest that the biological role of UV-triggered p21 degradation is to prevent replication defects by facilitating the tolerance of UV-induced DNA lesions.
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Affiliation(s)
- Sabrina F Mansilla
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir-CONICET, Buenos Aires C1405BWE, Argentina
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21
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Galectin-3 regulates p21 stability in human prostate cancer cells. Oncogene 2012; 32:5058-65. [PMID: 23160381 PMCID: PMC3910247 DOI: 10.1038/onc.2012.528] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/16/2012] [Accepted: 10/16/2012] [Indexed: 12/14/2022]
Abstract
Galectin-3 (Gal-3) is a multifunctional protein involved in cancer through regulation of cell adhesion, cell growth, apoptosis and metastasis, while p21 (Cip1/WAF1) is a negative regulator of the cell cycle, involved in apoptosis, transcription, DNA repair and metastasis. The results presented here demonstrate for the first time that the level of Gal-3 protein is associated with the level of p21 protein expression in human prostate cancer cells and the effects of Gal-3 on cell growth and apoptosis were reversed by modulating p21 expression level. Furthermore, Gal-3 regulates p21 expression at the post-translational level by stabilizing p21 protein via the carbohydrate-recognition domain. This is the first report suggesting a molecular function not yet described for Gal-3 as the regulator of p21 protein stability. This study provides a unique insight into the relationship of these two molecules during prostate cancer progression, and may provide a novel therapeutic target.
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22
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Chen X, Zhang J, Zhang M, Liu S, Yan W, Jung J, Chen X. Serine 123 phosphorylation modulates p21 protein stability and activity by suppressing ubiquitin-independent proteasomal degradation. J Biol Chem 2012; 287:34410-8. [PMID: 22908227 DOI: 10.1074/jbc.m112.384990] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The cyclin-dependent kinase inhibitor p21(Waf1/Cip1) is a major regulator of the cell cycle and plays an important role in many cellular processes, including differentiation, stress response, apoptosis, and tumorigenesis. We previously cloned the gene encoding dog p21 and found that unlike its human ortholog, dog p21 is expressed as two isoforms, one high molecular mass band of 23 kDa and one low molecular mass band of 19 kDa. In the current study, we found that the high molecular mass band is phosphorylated, whereas the low molecular mass band is hypophosphorylated. Moreover, by generating multiple mutants of dog p21, we found that serine 123 and proline 124, which form a consensus site for proline-directed phosphorylation, are required for expression of the high molecular mass p21 isoform through phosphorylation at serine 123. Most importantly, we showed that serine 123 phosphorylation inhibits ubiquitin-independent proteasomal degradation of p21 protein and subsequently, prolongs p21 protein half-life and enhances the ability of p21 to suppress cell proliferation. Taken together, these data reveal that serine 123 phosphorylation modulates p21 protein stability and activity by suppressing ubiquitin-independent proteasomal degradation.
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Affiliation(s)
- Xiangling Chen
- Comparative Oncology Laboratory, University of California, Davis, California 95616, USA
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23
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Regulation of the activation of the Fanconi anemia pathway by the p21 cyclin-dependent kinase inhibitor. Oncogene 2011; 31:366-75. [PMID: 21685936 DOI: 10.1038/onc.2011.237] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fanconi anemia (FA) is a rare disease characterized by congenital defects, progressive bone marrow failure and heightened cancer susceptibility. The FA proteins, BRCA1 and FANCD1/BRCA2 function cooperatively in the FA-BRCA pathway to repair damaged DNA. Activation of the FA-BRCA pathway occurs via the monoubiquitination of the FANCD2 and FANCI proteins, targeting these proteins to discrete nuclear foci where they function in DNA repair. The cellular regulation of FANCD2/I monoubiquitination, however, remains poorly understood. In this study, we have examined the roles of the p53 tumor suppressor protein, as well as its downstream target, the p21(Cip1/Waf1) cyclin-dependent kinase inhibitor, in the regulation of the activation of the FA-BRCA pathway. We demonstrate that, in contrast to p53, p21 has a major role in the regulation of the activation of the FA-BRCA pathway: p21 promotes S-phase and DNA damage-inducible FANCD2/I monoubiquitination and nuclear foci formation. Several lines of evidence establish that this effect is not a consequence of a defective G1-S checkpoint or altered cell-cycle progression in the absence of p21. Instead, we demonstrate that p21 is required for the transcriptional repression of the USP1 deubiquitinating enzyme upon exposure to DNA-damaging agents. In the absence of p21, persistent USP1 expression precludes the DNA damage-inducible accumulation of monoubiquitinated FANCD2 and FANCI. Consequently, p21(-/-) cells exhibit increased levels of mitomycin C-inducible complex chromosomal aberrations and elevated γH2AX nuclear foci formation. Our results demonstrate that p21 has a critical role in the regulation of the activation of the FA-BRCA pathway and suggest a broader role for p21 in the orchestration of DNA repair processes following exposure to DNA crosslinking agents.
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24
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PIDD orchestrates translesion DNA synthesis in response to UV irradiation. Cell Death Differ 2011; 18:1036-45. [PMID: 21415862 DOI: 10.1038/cdd.2011.19] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
PIDD has been implicated in survival and apoptotic pathways in response to DNA damage, and a role for PIDD was recently identified in non-homologous end-joining (NHEJ) repair induced by γ-irradiation. Here, we present an interaction of PIDD with PCNA, first identified in a proteomics screen. PCNA has essential functions in DNA replication and repair following UV irradiation. Translesion synthesis (TLS) is a process that prevents UV irradiation-induced replication blockage and is characterized by PCNA monoubiquitination and interaction with the TLS polymerase eta (polη). Both of these processes are inhibited by p21. We report that PIDD modulates p21-PCNA dissociation, and promotes PCNA monoubiquitination and interaction with polη in response to UV irradiation. Furthermore, PIDD deficiency leads to a defect in TLS that is associated, both in vitro and in vivo, with cellular sensitization to UV-induced apoptosis. Thus, PIDD performs key functions upon UV irradiation, including TLS, NHEJ, NF-κB activation and cell death.
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25
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Borin TF, Miyakawa AA, Cardoso L, de Figueiredo Borges L, Gonçalves GA, Krieger JE. Apoptosis, cell proliferation and modulation of cyclin-dependent kinase inhibitor p21(cip1) in vascular remodelling during vein arterialization in the rat. Int J Exp Pathol 2009; 90:328-37. [PMID: 19563615 DOI: 10.1111/j.1365-2613.2009.00648.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Neo-intima development and atherosclerosis limit long-term vein graft use for revascularization of ischaemic tissues. Using a rat model, which is technically less challenging than smaller rodents, we provide evidence that the temporal morphological, cellular, and key molecular events during vein arterialization resemble the human vein graft adaptation. Right jugular vein was surgically connected to carotid artery and observed up to 90 days. Morphometry demonstrated gradual thickening of the medial layer and important formation of neo-intima with deposition of smooth muscle cells (SMC) in the subendothelial layer from day 7 onwards. Transmission electron microscopy showed that SMCs switch from the contractile to synthetic phenotype on day 3 and new elastic lamellae formation occurs from day 7 onwards. Apoptosis markedly increased on day 1, while alpha-actin immunostaining for SMC almost disappeared by day 3. On day 7, cell proliferation reached the highest level and cellular density gradually increased until day 90. The relative magnitude of cellular changes was higher in the intima vs. the media layer (100 vs. 2 times respectively). Cyclin-dependent kinase inhibitors (CDKIs) p27(Kip1) and p16(INKA) remained unchanged, whereas p21(Cip1) was gradually downregulated, reaching the lowest levels by day 7 until day 90. Taken together, these data indicate for the first time that p21(Cip1) is the main CDKI protein modulated during the arterialization process the rat model of vein arterialization that may be useful to identify and validate new targets and interventions to improve the long-term patency of vein grafts.
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Affiliation(s)
- Thaiz Ferraz Borin
- Laboratory of Genetic and Molecular Cardiology/LIM-13, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil
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26
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Stewart JA, Miller AS, Campbell JL, Bambara RA. Dynamic removal of replication protein A by Dna2 facilitates primer cleavage during Okazaki fragment processing in Saccharomyces cerevisiae. J Biol Chem 2008; 283:31356-65. [PMID: 18799459 DOI: 10.1074/jbc.m805965200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic Okazaki fragments are initiated by a RNA/DNA primer, which is removed before the fragments are joined. Polymerase delta displaces the primer into a flap for processing. Dna2 nuclease/helicase and flap endonuclease 1 (FEN1) are proposed to cleave the flap. The single-stranded DNA-binding protein, replication protein A (RPA), governs cleavage activity. Flap-bound RPA inhibits FEN1. This necessitates cleavage by Dna2, which is stimulated by RPA. FEN1 then cuts the remaining RPA-free flap to create a nick for ligation. Cleavage by Dna2 requires that it enter the 5'-end and track down the flap. Because Dna2 cleaves the RPA-bound flap, we investigated the mechanism by which Dna2 accesses the protein-coated flap for cleavage. Using a nuclease-defective Dna2 mutant, we showed that just binding of Dna2 dissociates the flap-bound RPA. Facile dissociation is specific to substrates with a genuine flap, and will not occur with an RPA-coated single strand. We also compared the cleavage patterns of Dna2 with and without RPA to better define RPA stimulation of Dna2. Stimulation derived from removal of DNA folding in the flap. Apparently, coordinated with its dissociation, RPA relinquishes the flap to Dna2 for tracking in a way that does not allow flap structure to reform. We also found that RPA strand melting activity promotes excessive flap elongation, but it is suppressed by Dna2-promoted RPA dissociation. Overall, results indicate that Dna2 and RPA coordinate their functions for efficient flap cleavage and preparation for FEN1.
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Affiliation(s)
- Jason A Stewart
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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27
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Soria G, Speroni J, Podhajcer OL, Prives C, Gottifredi V. p21 differentially regulates DNA replication and DNA-repair-associated processes after UV irradiation. J Cell Sci 2008; 121:3271-82. [PMID: 18782865 DOI: 10.1242/jcs.027730] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although p21 upregulation is required to block cell-cycle progression following many types of genotoxic insult, UV irradiation triggers p21 proteolysis. The significance of the increased p21 turnover is unclear and might be associated with DNA repair. While the role of p21 in nucleotide excision repair (NER) remains controversial, recent reports have explored its effect on translesion DNA synthesis (TLS), a process that avoids replication blockage during S phase. Herein, we analyze the effect of p21 on different PCNA-driven processes including DNA replication, NER and TLS. Whereas only the CDK-binding domain of p21 is required for cell-cycle arrest in unstressed cells, neither the CDK-binding nor the PCNA-binding domain of p21 is able to block early and late steps of NER. Intriguingly, through its PCNA-binding domain, p21 inhibits the interaction of the TLS polymerase, pol eta (pol eta), with PCNA and impairs the assembly of pol eta foci after UV. Moreover, this obstruction correlates with accumulation of phosphorylated H2AX and increased apoptosis. By showing that p21 is a negative regulator of PCNA-pol eta interaction, our data unveil a link between efficient TLS and UV-induced degradation of p21.
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Affiliation(s)
- Gaston Soria
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir-CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
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28
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Gehen SC, Staversky RJ, Bambara RA, Keng PC, O'Reilly MA. hSMG-1 and ATM sequentially and independently regulate the G1 checkpoint during oxidative stress. Oncogene 2008; 27:4065-74. [PMID: 18332866 DOI: 10.1038/onc.2008.48] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Genotoxic stress activates the phosphatidylinositol 3-kinase-like kinases (PIKKs) that phosphorylate proteins involved in cell cycle arrest, DNA repair and apoptosis. Previous work showed that the PIKK ataxia telangiectasia mutated (ATM) but not ATM and Rad3 related phosphorylates p53 (Ser15) during hyperoxia, a model of prolonged oxidative stress and DNA damage. Here, we show hSMG-1 is responsible for the rapid and early phosphorylation of p53 (Ser15) and that ATM helps maintain phosphorylation after 24 h. Despite reduced p53 phosphorylation and abundance in cells depleted of hSMG-1 or ATM, levels of the p53 target p21 were still elevated and the G(1) checkpoint remained intact. Conditional overexpression of p21 in p53-deficient cells revealed that hyperoxia also stimulates wortmannin-sensitive degradation of p21. siRNA depletion of hSMG-1 or ATM restored p21 stability and the G(1) checkpoint during hyperoxia. These findings establish hSMG-1 as a proximal regulator of DNA damage signaling and reveal that the G(1) checkpoint is tightly regulated during prolonged oxidative stress by both PIKK-dependent synthesis and proteolysis of p21.
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Affiliation(s)
- S C Gehen
- Department of Environmental Medicine, The University of Rochester, Rochester, NY 14642, USA
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29
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Cazzalini O, Perucca P, Savio M, Necchi D, Bianchi L, Stivala LA, Ducommun B, Scovassi AI, Prosperi E. Interaction of p21(CDKN1A) with PCNA regulates the histone acetyltransferase activity of p300 in nucleotide excision repair. Nucleic Acids Res 2008; 36:1713-22. [PMID: 18263614 PMCID: PMC2275133 DOI: 10.1093/nar/gkn014] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The cell-cycle inhibitor p21CDKN1A has been suggested to directly participate in DNA repair, thanks to the interaction with PCNA. Yet, its role has remained unclear. Among proteins interacting with both p21 and PCNA, the histone acetyltransferase (HAT) p300 has been shown to participate in DNA repair. Here we report evidence indicating that p21 protein localizes and interacts with both p300 and PCNA at UV-induced DNA damage sites. The interaction between p300 and PCNA is regulated in vivo by p21. Indeed, loss of p21, or its inability to bind PCNA, results in a prolonged binding to chromatin and an increased association of p300 with PCNA, in UV-irradiated cells. Concomitantly, HAT activity of p300 is reduced after DNA damage. In vitro experiments show that inhibition of p300 HAT activity induced by PCNA is relieved by p21, which disrupts the association between recombinant p300 and PCNA. These results indicate that p21 is required during DNA repair to regulate p300 HAT activity by disrupting its interaction with PCNA.
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Affiliation(s)
- Ornella Cazzalini
- Dipartimento di Medicina Sperimentale, sez. Patologia Generale "C. Golgi", Università di Pavia, 27100 Pavia, Italy
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30
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Masih PJ, Kunnev D, Melendy T. Mismatch Repair proteins are recruited to replicating DNA through interaction with Proliferating Cell Nuclear Antigen (PCNA). Nucleic Acids Res 2007; 36:67-75. [PMID: 17984070 PMCID: PMC2248749 DOI: 10.1093/nar/gkm943] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Mismatch Repair (MMR) is closely linked to DNA replication; however, other than the role of the replicative sliding clamp (PCNA) in various MMR functions, the linkage between DNA replication and MMR has been difficult to investigate. Here we use an in vitro DNA replication system based on simian virus 40, to investigate MMR recruitment to replicating DNA. Both DNA replication and MMR proteins are recruited to replicating DNA in an origin-dependent fashion. Primer synthesis is required for recruitment of both PCNA and MMR proteins, but not for recruitment of the single-stranded DNA-binding protein (RPA). Blocking PCNA recruitment to replicating DNA with a p21-based polypeptide blocks PCNA and MMR, but not RPA recruitment. Once PCNA and subsequent proteins required for replication are loaded onto DNA, addition of p21 leaves PCNA on the replicating DNA, but actively displaces MMR proteins. These findings indicate that the MMR machinery is recruited to replicating DNA through its interaction with PCNA, and suggests that this occurs via binding of the MMR proteins to the multi-protein interaction sites on PCNA. These studies demonstrate the utility of this system for further investigation of the role of DNA replication in MMR.
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Affiliation(s)
- Prerna Jasmine Masih
- Department of Cellular and Molecular Biology, Roswell Park Cancer Institute, Buffalo, NY 14214, USA
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31
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Stewart JA, Campbell JL, Bambara RA. Flap endonuclease disengages Dna2 helicase/nuclease from Okazaki fragment flaps. J Biol Chem 2006; 281:38565-72. [PMID: 17038322 DOI: 10.1074/jbc.m606884200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Okazaki fragments contain an initiator RNA/DNA primer that must be removed before the fragments are joined. In eukaryotes, the primer region is raised into a flap by the strand displacement activity of DNA polymerase delta. The Dna2 helicase/nuclease and then flap endonuclease 1 (FEN1) are proposed to act sequentially in flap removal. Dna2 and FEN1 both employ a tracking mechanism to enter the flap 5' end and move toward the base for cleavage. In the current model, Dna2 must enter first, but FEN1 makes the final cut at the flap base, raising the issue of how FEN1 passes the Dna2. To address this, nuclease-inactive Dna2 was incubated with a DNA flap substrate and found to bind with high affinity. FEN1 was then added, and surprisingly, there was little inhibition of FEN1 cleavage activity. FEN1 was later shown, by gel shift analysis, to remove the wild type Dna2 from the flap. RNA can be cleaved by FEN1 but not by Dna2. Pre-bound wild type Dna2 was shown to bind an RNA flap but not inhibit subsequent FEN1 cleavage. These results indicate that there is a novel interaction between the two proteins in which FEN1 disengages the Dna2 tracking mechanism. This interaction is consistent with the idea that the two proteins have evolved a special ability to cooperate in Okazaki fragment processing.
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Affiliation(s)
- Jason A Stewart
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
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32
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Rossi ML, Purohit V, Brandt PD, Bambara RA. Lagging strand replication proteins in genome stability and DNA repair. Chem Rev 2006; 106:453-73. [PMID: 16464014 DOI: 10.1021/cr040497l] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Marie L Rossi
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, New York 14642, USA
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33
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Perucca P, Cazzalini O, Mortusewicz O, Necchi D, Savio M, Nardo T, Stivala LA, Leonhardt H, Cardoso MC, Prosperi E. Spatiotemporal dynamics of p21CDKN1A protein recruitment to DNA-damage sites and interaction with proliferating cell nuclear antigen. J Cell Sci 2006; 119:1517-27. [PMID: 16551699 DOI: 10.1242/jcs.02868] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The cyclin-dependent kinase inhibitor p21CDKN1A plays a fundamental role in the DNA-damage response by inducing cell-cycle arrest, and by inhibiting DNA replication through association with the proliferating cell nuclear antigen (PCNA). However, the role of such an interaction in DNA repair is poorly understood and controversial. Here, we provide evidence that a pool of p21 protein is rapidly recruited to UV-induced DNA-damage sites, where it colocalises with PCNA and PCNA-interacting proteins involved in nucleotide excision repair (NER), such as DNA polymerase δ, XPG and CAF-1. In vivo imaging and confocal fluorescence microscopy analysis of cells coexpressing p21 and PCNA fused to green or red fluorescent protein (p21-GFP, RFP-PCNA), showed a rapid relocation of both proteins at microirradiated nuclear spots, although dynamic measurements suggested that p21-GFP was recruited with slower kinetics. An exogenously expressed p21 mutant protein unable to bind PCNA neither colocalised, nor coimmunoprecipitated with PCNA after UV irradiation. In NER-deficient XP-A fibroblasts, p21 relocation was greatly delayed, concomitantly with that of PCNA. These results indicate that early recruitment of p21 protein to DNA-damage sites is a NER-related process dependent on interaction with PCNA, thus suggesting a direct involvement of p21 in DNA repair.
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Affiliation(s)
- Paola Perucca
- Dipartimento di Medicina Sperimentale, sez. Patologia generale, Università di Pavia, 27100 Pavia, Italy
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34
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Soria G, Podhajcer O, Prives C, Gottifredi V. P21Cip1/WAF1 downregulation is required for efficient PCNA ubiquitination after UV irradiation. Oncogene 2006; 25:2829-38. [PMID: 16407842 DOI: 10.1038/sj.onc.1209315] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
p21(Cip1/WAF1) is a known inhibitor of the short-gap filling activity of proliferating cell nuclear antigen (PCNA) during DNA repair. In agreement, p21 degradation after UV irradiation promotes PCNA-dependent repair. Recent reports have identified ubiquitination of PCNA as a relevant feature for PCNA-dependent DNA repair. Here, we show that PCNA ubiquitination in human cells is notably augmented after UV irradiation and other genotoxic treatments such as hydroxyurea, aphidicolin and methylmethane sulfonate. Intriguingly, those DNA damaging agents also promoted downregulation of p21. While ubiquitination of PCNA was not affected by deficient nucleotide excision repair (NER) and was observed in both proliferating and arrested cells, stable p21 expression caused a significant reduction in UV-induced ubiquitinated PCNA. Surprisingly, the negative regulation of PCNA ubiquitination by p21 does not depend on the direct interaction with PCNA but requires the cyclin dependent kinase binding domain of p21. Taken together, our data suggest that p21 downregulation plays a role in efficient PCNA ubiquitination after UV irradiation.
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Affiliation(s)
- G Soria
- Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
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35
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Abstract
DNA in living cells is constantly subjected to different chemical and physical factors of the environment and to cell metabolites. Some changes altering DNA structure occur spontaneously. This raises the potential danger of harmful mutations that could be transmitted to offspring. To avoid the danger of mutations and changing genetic information, a cell is capable to switch on multiple mechanisms of DNA repair that remove damage and restore native structure. In many cases, removal of the same damage may involve several alternative pathways; this is very important for DNA repair under the most unfavorable conditions. This review summarizes data about all known mechanisms of eukaryotic DNA repair including excision repair (base excision repair and nucleotide excision repair), mismatch repair, repair of double-strand breaks, and cross-link repair. Special attention is given to the regulation of excision repair by different proteins--proliferating cell nuclear antigen (PCNA), p53, and proteasome. The review also highlights problem of bypassing irremovable lesions in DNA.
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Affiliation(s)
- N P Sharova
- Kol'tsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow 119334, Russia.
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36
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Li Y, Wang L, Li S, Guo T, Guo X, Yan P, Chen Y, Wang L, Lu C. p53 protein activates the transcription of human proliferating cell nuclear antigen in response to 4-nitroquinoline N-oxide treatment. Int J Biochem Cell Biol 2005; 37:416-26. [PMID: 15474986 DOI: 10.1016/j.biocel.2004.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 06/25/2004] [Accepted: 07/16/2004] [Indexed: 11/28/2022]
Abstract
4-nitroquinoline N-oxide (4-NQO) is a potent mutagen and carcinogen. To elucidate the cellular response to 4-NQO, we studied the transcriptional regulation of human proliferating cell nuclear antigen (hPCNA), an essential protein in DNA replication and repair, after 4-NQO treatment. We found that hPCNA promoter was dose-dependently transactivated by 4-NQO under the concentration of 2 microM via a previously reported p53-binding element located from -236 to -217 upstream of the transcription start site. Based on our western blot analysis, the phosphorylation of serine at the 15th residue (Ser15) of p53 was activated by 4-NQO, whereas the level of p53 in the cells did not change much. It was observed that Staurosporine, a Ser/Thr kinase inhibitor, blocked the Ser15 phosphorylation of p53 and the hPCNA promoter response to 4-NQO simultaneously, suggesting that Ser15 phosphorylated p53 was the 4-NQO-responsive hPCNA regulator. The [3H]-thymidine deoxyribose (TdR) incorporation assay and the comet assay showed that DNA repair was triggered when DNA replication was inhibited after the treatment of 4-NQO, and the hPCNA transactivation seemed to contribute to DNA repair. Taken together, our data indicate that after 4-NQO treatment hPCNA is transactivated by Ser15 phosphorylated p53, and participate in DNA repair.
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Affiliation(s)
- Yuanyuan Li
- Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, 200031 Shanghai, PR China
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37
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Naderi S, Wang JYJ, Chen TT, Gutzkow KB, Blomhoff HK. cAMP-mediated inhibition of DNA replication and S phase progression: involvement of Rb, p21Cip1, and PCNA. Mol Biol Cell 2005; 16:1527-42. [PMID: 15647383 PMCID: PMC551513 DOI: 10.1091/mbc.e04-06-0501] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
cAMP exerts an antiproliferative effect on a number of cell types including lymphocytes. This effect of cAMP is proposed to be mediated by its ability to inhibit G1/S transition. In this report, we provide evidence for a new mechanism whereby cAMP might inhibit cellular proliferation. We show that elevation of intracellular levels of cAMP inhibits DNA replication and arrests the cells in S phase. The cAMP-induced inhibition of DNA synthesis was associated with the increased binding of p21Cip1 to Cdk2-cyclin complexes, inhibition of Cdk2 kinase activity, dephosphorylation of Rb, and dissociation of PCNA from chromatin in S phase cells. The ability of cAMP to inhibit DNA replication and trigger release of PCNA from chromatin required Rb and p21Cip1 proteins, since both processes were only marginally affected by increased levels of cAMP in Rb-/- and p21Cip1-/- 3T3 fibroblasts. Importantly, the implications of cAMP-induced inhibition of DNA synthesis in cancer treatment was demonstrated by the ability of cAMP to reduce apoptosis induced by S phase-specific cytotoxic drugs. Taken together, these results demonstrate a novel role for cAMP in regulation of DNA synthesis and support a model in which activation of cAMP-dependent signaling protects cells from the effect of S phase-specific antitumor agents.
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Affiliation(s)
- Soheil Naderi
- Institute of Basic Medical Sciences, Department of Biochemistry, University of Oslo, Oslo N-0317, Norway.
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38
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Wang W, Brandt P, Rossi ML, Lindsey-Boltz L, Podust V, Fanning E, Sancar A, Bambara RA. The human Rad9-Rad1-Hus1 checkpoint complex stimulates flap endonuclease 1. Proc Natl Acad Sci U S A 2004; 101:16762-7. [PMID: 15556996 PMCID: PMC534749 DOI: 10.1073/pnas.0407686101] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The toroidal damage checkpoint complex Rad9-Rad1-Hus1 (9-1-1) has been characterized as a sensor of DNA damage. Flap endonuclease 1 (FEN1) is a structure-specific nuclease involved both in removing initiator RNA from Okazaki fragments and in DNA repair pathways. FEN1 activity is stimulated by proliferating cell nuclear antigen (PCNA), a toroidal sliding clamp that acts as a platform for DNA replication and repair complexes. We show that 9-1-1 also binds and stimulates FEN1. Stimulation is observed on a variety of flap, nick, and gapped substrates simulating repair intermediates. Blocking 9-1-1 entry to the double strands prevents a portion of the stimulation. Like PCNA stimulation, 9-1-1 stimulation cannot circumvent the tracking mechanism by which FEN1 enters the substrate; however, 9-1-1 does not substitute for PCNA in the stimulation of DNA polymerase beta. This suggests that 9-1-1 is a damage-specific activator of FEN1.
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Affiliation(s)
- Wensheng Wang
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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39
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Vidal AE, Kannouche P, Podust VN, Yang W, Lehmann AR, Woodgate R. Proliferating Cell Nuclear Antigen-dependent Coordination of the Biological Functions of Human DNA Polymerase ι. J Biol Chem 2004; 279:48360-8. [PMID: 15342632 DOI: 10.1074/jbc.m406511200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Y-family DNA polymerases are believed to facilitate the replicative bypass of damaged DNA in a process commonly referred to as translesion synthesis. With the exception of DNA polymerase eta (poleta), which is defective in humans with the Xeroderma pigmentosum variant (XP-V) phenotype, little is known about the cellular function(s) of the remaining human Y-family DNA polymerases. We report here that an interaction between human DNA polymerase iota (poliota) and the proliferating cell nuclear antigen (PCNA) stimulates the processivity of poliota in a template-dependent manner in vitro. Mutations in one of the putative PCNA-binding motifs (PIP box) of poliota or the interdomain connector loop of PCNA diminish the binding between poliota and PCNA and concomitantly reduce PCNA-dependent stimulation of poliota activity. Furthermore, although retaining its capacity to interact with poleta in vivo, the poliota-PIP box mutant fails to accumulate in replication foci. Thus, PCNA, acting as both a scaffold and a modulator of the different activities involved in replication, appears to recruit and coordinate replicative and translesion DNA synthesis polymerases to ensure genome integrity.
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Affiliation(s)
- Antonio E Vidal
- Laboratory of Genomic Integrity, NICHD, National Institutes of Health, Bethesda, Maryland 20892-2725, USA
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40
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Maga G, Blanca G, Shevelev I, Frouin I, Ramadan K, Spadari S, Villani G, Hübscher U. The human DNA polymerase lambda interacts with PCNA through a domain important for DNA primer binding and the interaction is inhibited by p21/WAF1/CIP1. FASEB J 2004; 18:1743-5. [PMID: 15358682 DOI: 10.1096/fj.04-2268fje] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this paper we show that DNA polymerase lambda (pol lambda) interacts with proliferating cell nuclear antigen (PCNA) in vivo in human cells. Moreover, by using recombinant mutated PCNA, we could demonstrate that pol lambda interacts with both the interdomain-connecting loop and the nearby hydrophobic pocket on the anterior of PCNA and that critical residues within a helix-hairpin-helix domain of pol lambda, important for proper DNA primer binding, are also involved in the enzyme's interaction with PCNA. Finally, we show that the tumor suppressor protein p21(WAF1/CIP1) can efficiently compete in vitro with pol lambda for binding to PCNA. Given the high rate of frameshift mutations induced by pol lambda and its ability to bypass abasic sites, accurate regulation of pol lambda activity by PCNA and p21 concerted action might be important for preventing genetic instability.
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Affiliation(s)
- Giovanni Maga
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, Pavia, Italy.
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41
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Toueille M, Hübscher U. Regulation of the DNA replication fork: a way to fight genomic instability. Chromosoma 2004; 113:113-25. [PMID: 15300444 DOI: 10.1007/s00412-004-0303-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 06/15/2004] [Accepted: 06/17/2004] [Indexed: 12/18/2022]
Abstract
DNA replication is a complex mechanism that functions due to the coordinated interplay of many factors. In the last few years, numerous studies have suggested that DNA replication factors are closely implicated in several DNA transaction events that maintain the integrity of the genome. Therefore, DNA replication fork factors have to be considered as part of a general process that aims to protect and replicate the genome in order to allow correct functioning of a cell and its eventual daughter cells. This is illustrated by the numerous factors that have a well-defined function at the DNA replication fork, but also play crucial roles in different DNA repair pathways such as base excision repair, nucleotide excision repair, double-strand break repair, and mismatch repair. Moreover, several of the replisome proteins have also been shown to be essential in sensing and transducing DNA damages through the checkpoint cascade pathways, including the recently characterised alternative clamps and clamp-loaders. In this review we present DNA replication factors that are involved in different DNA transaction and checkpoint regulation pathways, with emphasis on the link between DNA replication and maintenance of genomic stability.
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Affiliation(s)
- Magali Toueille
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich-Irchel, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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42
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Dong C, Lyu SC, Krensky AM, Clayberger C. DQ 65–79, A Peptide Derived from HLA Class II, Mimics p21 to Block T Cell Proliferation. THE JOURNAL OF IMMUNOLOGY 2003; 171:5064-70. [PMID: 14607903 DOI: 10.4049/jimmunol.171.10.5064] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DQ 65-79, a peptide derived from residues 65-79 of the alpha-chain HLA class II molecule DQA03011, blocks T cell proliferation and induces T cell apoptosis. Using a yeast two-hybrid assay, we previously identified proliferating cell nuclear Ag (PCNA) as an intracellular ligand for DQ 65-79. In this study, we show that three regions of PCNA, residues 81-100, 121-140, and 241-261, interact with DQ 65-79. Residues 241-261 of PCNA also interact with the C terminus (residues 139-160) of the cell cycle regulator, p21, suggesting that DQ 65-79 and p21 might function similarly. We show here that DQ 65-79 competitively inhibits binding of p21 to PCNA and that both DQ 65-79 and p21 139-160 induce T cell apoptosis, suggesting that DQ 65-79 and p21 act similarly to inhibit cell growth.
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Affiliation(s)
- Chen Dong
- Division of Immunology and Transplantation Biology, Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
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43
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Gottifredi V, McKinney K, Poyurovsky MV, Prives C. Decreased p21 levels are required for efficient restart of DNA synthesis after S phase block. J Biol Chem 2003; 279:5802-10. [PMID: 14597617 DOI: 10.1074/jbc.m310373200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The cyclin-dependent kinase inhibitor p21, a major transcriptional target of the tumor suppressor p53, plays a critical role in cell cycle arrest in G1 and G2 after DNA damage. It was previously shown that in some human cell lines when S phase is arrested, p53 is transcriptionally impaired such that some p53 targets including p21 are only weakly induced. We show here that during S phase arrest proteasome-mediated turnover of p21 is significantly increased in a manner that is independent of p53. It is well established that p21 can interact both with cyclin-dependent kinase complexes and with proliferating cell nuclear antigen (PCNA). Interestingly, the scant amount of p21 detected during S phase block cannot fully saturate cyclin A-cyclin-dependent kinase 2 complexes and does not interact detectably with PCNA. Importantly, DNA elongation assays in isolated nuclei show that the C terminus of p21 containing the PCNA-binding domain effectively blocks this process. This implies that p21 down-regulation could be an essential requirement for efficient restart of DNA synthesis. In line with this, only cells expressing low levels of p21 immediately progress through the cell cycle upon release from S phase arrest, whereas the remaining few high p21 producing cells move much more slowly through S. Thus, p21 down-regulation is multiply determined and is required for the reversibility of the arrest in S phase.
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Affiliation(s)
- Vanesa Gottifredi
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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44
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Bendjennat M, Boulaire J, Jascur T, Brickner H, Barbier V, Sarasin A, Fotedar A, Fotedar R. UV irradiation triggers ubiquitin-dependent degradation of p21(WAF1) to promote DNA repair. Cell 2003; 114:599-610. [PMID: 13678583 DOI: 10.1016/j.cell.2003.08.001] [Citation(s) in RCA: 208] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
p53-mediated increase in cyclin-dependent kinase inhibitor p21(WAF1) protein is thought to be the major mediator of cell cycle arrest after DNA damage. Previously p21 protein levels have been reported to increase or to decrease after UV irradiation. We show that p21 protein is degraded after irradiation of a variety of cell types with low but not high doses of UV. Cell cycle arrest occurs despite p21 degradation via Tyr(15) inhibitory phosphorylation of cdk2 and differs from the classical p21-dependent checkpoint elicited by ionizing radiation. In contrast to the basal turnover of p21, degradation of p21 switches to ubiquitin/Skp2-dependent proteasome pathway following UV irradiation. ATR activation after UV irradiation is essential for signaling p21 degradation. Finally, UV-induced p21 degradation is essential for optimal DNA repair. These results provide novel insight into regulation of p21 protein and its role in the cellular response to DNA damage.
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Affiliation(s)
- Mourad Bendjennat
- Institut de Biologie Structurale J.-P. Ebel, 41 rue Jules Horowitz, F38027 Grenoble, France
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45
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Maga G, Hubscher U. Proliferating cell nuclear antigen (PCNA): a dancer with many partners. J Cell Sci 2003; 116:3051-60. [PMID: 12829735 DOI: 10.1242/jcs.00653] [Citation(s) in RCA: 807] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Proliferating cell nuclear antigen (PCNA) was originally characterised as a DNA sliding clamp for replicative DNA polymerases and as an essential component of the eukaryotic chromosomal DNA replisome. Subsequent studies, however, have revealed its striking ability to interact with multiple partners, which are involved in several metabolic pathways, including Okazaki fragment processing, DNA repair, translesion DNA synthesis, DNA methylation, chromatin remodeling and cell cycle regulation. PCNA in mammalian cells thus appears to play a key role in controlling several reactions through the coordination and organisation of different partners. Two major questions have emerged: how do these proteins access PCNA in a coordinated manner, and how does PCNA temporally and spatially organise their functions? Structural and biochemical studies are starting to provide a first glimpse of how both tasks can be achieved.
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Affiliation(s)
- Giovanni Maga
- DNA Enzymology and Molecular Virology, Istituto di Genetica Molecolare, IGM-CNR, National Research Council, via Abbiategrasso 207, I-27100 Pavia, Italy
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46
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Gururaja TL, Li W, Payan DG, Anderson DC. Utility of peptide-protein affinity complexes in proteomics: identification of interaction partners of a tumor suppressor peptide. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2003; 61:163-76. [PMID: 12605602 DOI: 10.1034/j.1399-3011.2003.00044.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We used a N-biotinylated peptide analog of the C-terminal domain of the tumor suppressor protein, p21cip1/waf1 to elucidate peptide/protein interacting partners. The C-terminal domain of p21cip1/waf1 protein spanning 141-160 amino acid residues is known to bind PCNA and this interaction is important in many biological processes including cell-cycle control. This C-terminal 20-mer efficiently extracts PCNA in the presence of a variety of N- or C-terminally attached affinity tags. Using difference silver stained 2D gels combined with in-gel tryptic digests, we identified the difference spots using MALDI-TOF mass spectrometry-based peptide mass fingerprinting followed by a database search using PROFOUND against NCBIs human nonredundant protein sequence data bank. Identified spots include the p48 subunit of chromatin assembly factor-1, the heat shock 70 protein analog BiP, calmodulin, nucleolin and a spot similar in size to dimeric PCNA. In contrast, microcapillary ion-trap LC-MS/MS analysis of a tryptic digest of entire affinity extracts derived from both control and experimental runs followed by database searches using SEQUEST confirmed the presence of most of the above proteins. This strategy also identified hnRNPA1, HPSP90alpha, HSP40 and T-complex protein 1, a protein similar to prothymosin, and a possible allelic variant of the p21cip1/waf1 protein. The use of N-biotinylated peptide derived from the C-terminal domain of p21cip1/waf1 protein in proteomic analysis exemplified here suggests that peptides obtained from intracellular functional screens could also potentially serve as efficient baits to discover new drug targets.
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Affiliation(s)
- T L Gururaja
- Rigel Pharmaceuticals Inc, San Francisco, CA 94080, USA.
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47
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Takamura Y, Kubo E, Tsuzuki S, Yagi H, Sato M, Akagi Y. Increased expression of p21(WAF-1/CIP-1) in the lens epithelium of rat sugar cataract. Exp Eye Res 2002; 74:245-54. [PMID: 11950235 DOI: 10.1006/exer.2001.1120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been demonstrated that exquisite regulation of the cell cycle between the activation and inhibition is crucial to maintain the transparency of the ocular lens. While it is generally recognized that the sugar cataract is accompanied by the enhanced proliferation of lens epithelial cells (LECs), it is unclear whether or not an inhibitory mechanism against the lens proliferation is involved, except for TGF-beta. In this study, the authors demonstrated the enhanced expression of p21(WAF-1/CIP-1), a potent inhibitor against cell cycle progression, and its specific temporal and regional expression profiles in the LECs during the development of sugar cataract. Sugar cataract was induced in 6-week-old male Sprague-Dawley rats by feeding them on a 50% galactose-rich diet, and then the expression patterns of p21(WAF-1/CIP-1) mRNA and protein with the advance of the sugar cataract were studied. Western blot analyses showed that p21(WAF-1/CIP-1) expression increased throughout the period of galactose exposure, up to 21 days. Also, a gradual increase in the number of p21(WAF-1/CIP-1) positive cells was observed immunohistochemically in the course of the galactose exposure. Interestingly, p21(WAF-1/CIP-1) was significantly expressed in the multi-layered epithelium, which was observed typically in the advanced cataract. Proliferating cell nuclear antigen (PCNA), an indicator of cell proliferation, was also positive in the most multi-layered epithelial cells. In addition, transient expression of PCNA mRNA and its protein was noticed throughout the lens epithelium in the course of the sugar cataract development. Prior to the elevation of p21(WAF-1/CIP-1) mRNA expression, PCNA mRNA expression increased greatly and reached a peak according to the semiquantitative analyses using either the real time reverse transcription-polymerase chain reaction (RT-PCR) or the Southern blot analyses. Based on these observations, it is possible that p21(WAF-1/CIP-1) is elevated and exerts its inhibitory action against the proliferating epithelial cells during the development of the sugar cataract.
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Affiliation(s)
- Yoshihiro Takamura
- Department of Ophthalmology, Fukui Medical University, Shimoaizuki, Matsuoka, Fukui 910 1193, Japan
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48
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Tom S, Ranalli TA, Podust VN, Bambara RA. Regulatory roles of p21 and apurinic/apyrimidinic endonuclease 1 in base excision repair. J Biol Chem 2001; 276:48781-9. [PMID: 11641413 DOI: 10.1074/jbc.m109626200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many types of DNA damage induce a cellular response that inhibits replication but allows repair by up-regulating the p53 pathway and inducing p21(Cip1, Waf1, Sdi1). The p21 regulatory protein can bind proliferating cell nuclear antigen (PCNA) and prohibit DNA replication. We show here that p21 also inhibits PCNA stimulation of long patch base excision repair (BER) in vitro. p21 disrupts PCNA-directed stimulation of flap endonuclease 1 (FEN1), DNA ligase I, and DNA polymerase delta. The dilemma is to understand how p21 prevents DNA replication but allows BER in vivo. Differential regulation by p21 is likely to relate to the utilization of DNA polymerase beta, which is not sensitive to p21, in the repair pathway. We have also found that apurinic/apyrimidinic endonuclease 1 (APE1) stimulates long patch BER. Furthermore, neither APE1 activity nor its ability to stimulate long patch BER is significantly affected by p21 in vitro. We propose that APE1 serves as an assembly and coordination factor for long patch BER proteins. APE1 initially cleaves the DNA and then facilitates the sequential binding and catalysis by DNA polymerase beta, DNA polymerase delta, FEN1, and DNA ligase I. This model implies that BER can be regulated differentially, based upon the assembly of relevant proteins around APE1 in the presence or absence of PCNA.
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Affiliation(s)
- S Tom
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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Ducoux M, Urbach S, Baldacci G, Hübscher U, Koundrioukoff S, Christensen J, Hughes P. Mediation of proliferating cell nuclear antigen (PCNA)-dependent DNA replication through a conserved p21(Cip1)-like PCNA-binding motif present in the third subunit of human DNA polymerase delta. J Biol Chem 2001; 276:49258-66. [PMID: 11595739 DOI: 10.1074/jbc.m106990200] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The subunit that mediates binding of proliferating cell nuclear antigen (PCNA) to human DNA polymerase delta has not been clearly defined. We show that the third subunit of human DNA polymerase delta, p66, interacts with PCNA through a canonical PCNA-binding sequence located in its C terminus. Conversely, p66 interacts with the domain-interconnecting loop of PCNA, a region previously shown to be important for DNA polymerase delta activity and for binding of the cell cycle inhibitor p21(Cip1). In accordance with this, a peptide containing the PCNA-binding domain of p21(Cip1) inhibited p66 binding to PCNA and the activity of native three-subunit DNA polymerase delta. Furthermore, pull-down assays showed that DNA polymerase delta requires p66 for interaction with PCNA. More importantly, only reconstituted three-subunit DNA polymerase delta displayed PCNA-dependent DNA replication that could be inhibited by the PCNA-binding domain of p21(Cip1). Direct participation of p66 in PCNA-dependent DNA replication in vivo is demonstrated by co-localization of p66 with PCNA and DNA polymerase delta within DNA replication foci. Finally, in vitro phosphorylation of p66 by cyclin-dependent kinases suggests that p66 activity may be subject to cell cycle-dependent regulation. These results suggest that p66 is the chief mediator of PCNA-dependent DNA synthesis by DNA polymerase delta.
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Affiliation(s)
- M Ducoux
- Institut Curie, UMR 2027 du CNRS, Génotoxicologie et Cycle Cellulaire, Bâtiment 110, Centre Universitaire, 91405 Orsay Cedex, France
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50
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Scott M, Bonnefin P, Vieyra D, Boisvert FM, Young D, Bazett-Jones DP, Riabowol K. UV-induced binding of ING1 to PCNA regulates the induction of apoptosis. J Cell Sci 2001; 114:3455-62. [PMID: 11682605 DOI: 10.1242/jcs.114.19.3455] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous studies have shown that UV-induced binding of p21WAF1 to PCNA through the PCNA-interacting protein (PIP) domain in p21WAF1 promotes a switch from DNA replication to DNA repair by altering the PCNA protein complex. Here we show that the p33ING1b isoform of the ING1 candidate tumour suppressor contains a PIP domain. UV rapidly induces p33ING1b to bind PCNA competitively through this domain, a motif also found in DNA ligase, the DNA repair-associated FEN1 and XPG exo/endonucleases, and DNA methyltransferase. Interaction of p33ING1b with PCNA occurs between a significant proportion of ING1 and PCNA, increases more than tenfold in response to UV and is specifically inhibited by overexpression of p21WAF1, but not by p16MTS1, which has no PIP sequence. In contrast to wild-type p33ING1b, ING1 PIP mutants that do not bind PCNA do not induce apoptosis, but protect cells from UV-induced apoptosis, suggesting a role for this PCNA-p33ING1b interaction in eliminating UV-damaged cells through programmed cell death. These data indicate that ING1 competitively binds PCNA through a site used by growth regulatory and DNA damage proteins, and may contribute to regulating the switch from DNA replication to DNA repair by altering the composition of the PCNA protein complex.
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Affiliation(s)
- M Scott
- Department of Biochemistry, Faculty of Medicine, The University of Calgary, 3330 Hospital Drive, NW, Calgary, Alberta T2N 4N1, Canada
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