1
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Nasheuer HP, Meaney AM. Starting DNA Synthesis: Initiation Processes during the Replication of Chromosomal DNA in Humans. Genes (Basel) 2024; 15:360. [PMID: 38540419 PMCID: PMC10969946 DOI: 10.3390/genes15030360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 03/09/2024] [Accepted: 03/11/2024] [Indexed: 06/14/2024] Open
Abstract
The initiation reactions of DNA synthesis are central processes during human chromosomal DNA replication. They are separated into two main processes: the initiation events at replication origins, the start of the leading strand synthesis for each replicon, and the numerous initiation events taking place during lagging strand DNA synthesis. In addition, a third mechanism is the re-initiation of DNA synthesis after replication fork stalling, which takes place when DNA lesions hinder the progression of DNA synthesis. The initiation of leading strand synthesis at replication origins is regulated at multiple levels, from the origin recognition to the assembly and activation of replicative helicase, the Cdc45-MCM2-7-GINS (CMG) complex. In addition, the multiple interactions of the CMG complex with the eukaryotic replicative DNA polymerases, DNA polymerase α-primase, DNA polymerase δ and ε, at replication forks play pivotal roles in the mechanism of the initiation reactions of leading and lagging strand DNA synthesis. These interactions are also important for the initiation of signalling at unperturbed and stalled replication forks, "replication stress" events, via ATR (ATM-Rad 3-related protein kinase). These processes are essential for the accurate transfer of the cells' genetic information to their daughters. Thus, failures and dysfunctions in these processes give rise to genome instability causing genetic diseases, including cancer. In their influential review "Hallmarks of Cancer: New Dimensions", Hanahan and Weinberg (2022) therefore call genome instability a fundamental function in the development process of cancer cells. In recent years, the understanding of the initiation processes and mechanisms of human DNA replication has made substantial progress at all levels, which will be discussed in the review.
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Affiliation(s)
- Heinz Peter Nasheuer
- Centre for Chromosome Biology, School of Biological and Chemical Sciences, Biochemistry, University of Galway, H91 TK33 Galway, Ireland;
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2
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Chen J, Potlapalli R, Quan H, Chen L, Xie Y, Pouriyeh S, Sakib N, Liu L, Xie Y. Exploring DNA Damage and Repair Mechanisms: A Review with Computational Insights. BIOTECH 2024; 13:3. [PMID: 38247733 PMCID: PMC10801582 DOI: 10.3390/biotech13010003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 11/21/2023] [Accepted: 12/29/2023] [Indexed: 01/23/2024] Open
Abstract
DNA damage is a critical factor contributing to genetic alterations, directly affecting human health, including developing diseases such as cancer and age-related disorders. DNA repair mechanisms play a pivotal role in safeguarding genetic integrity and preventing the onset of these ailments. Over the past decade, substantial progress and pivotal discoveries have been achieved in DNA damage and repair. This comprehensive review paper consolidates research efforts, focusing on DNA repair mechanisms, computational research methods, and associated databases. Our work is a valuable resource for scientists and researchers engaged in computational DNA research, offering the latest insights into DNA-related proteins, diseases, and cutting-edge methodologies. The review addresses key questions, including the major types of DNA damage, common DNA repair mechanisms, the availability of reliable databases for DNA damage and associated diseases, and the predominant computational research methods for enzymes involved in DNA damage and repair.
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Affiliation(s)
- Jiawei Chen
- College of Letter and Science, University of California, Berkeley, CA 94720, USA;
| | - Ravi Potlapalli
- College of Computing and Software Engineering, Kennesaw State University, Marietta, GA 30060, USA; (L.C.); (R.P.); (Y.X.); (S.P.); (N.S.)
| | - Heng Quan
- Department of Civil and Urban Engineering, New York University, New York, NY 11201, USA;
| | - Lingtao Chen
- College of Computing and Software Engineering, Kennesaw State University, Marietta, GA 30060, USA; (L.C.); (R.P.); (Y.X.); (S.P.); (N.S.)
| | - Ying Xie
- College of Computing and Software Engineering, Kennesaw State University, Marietta, GA 30060, USA; (L.C.); (R.P.); (Y.X.); (S.P.); (N.S.)
| | - Seyedamin Pouriyeh
- College of Computing and Software Engineering, Kennesaw State University, Marietta, GA 30060, USA; (L.C.); (R.P.); (Y.X.); (S.P.); (N.S.)
| | - Nazmus Sakib
- College of Computing and Software Engineering, Kennesaw State University, Marietta, GA 30060, USA; (L.C.); (R.P.); (Y.X.); (S.P.); (N.S.)
| | - Lichao Liu
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA 94304, USA;
| | - Yixin Xie
- College of Computing and Software Engineering, Kennesaw State University, Marietta, GA 30060, USA; (L.C.); (R.P.); (Y.X.); (S.P.); (N.S.)
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3
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Loeillet S, Nicolas A. DNA polymerase δ: A single Pol31 polymorphism suppresses the strain background-specific lethality of Pol32 inactivation in Saccharomyces cerevisiae. DNA Repair (Amst) 2023; 127:103514. [PMID: 37244009 DOI: 10.1016/j.dnarep.2023.103514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/12/2023] [Accepted: 05/14/2023] [Indexed: 05/29/2023]
Abstract
The evolutionarily conserved DNA polymerase delta (Polδ) plays several essential roles in eukaryotic DNA replication and repair, responsible for the synthesis of the lagging-strand, lower replicative mutagenesis via its proof-reading exonuclease activity and synthetizes both strands during break-induced replication. In Saccharomyces cerevisiae, the Polδ protein complex consists of three subunits encoded by the POL3, POL31 and POL32 genes. Surprisingly, in contrast to POL3 and POL31, the POL32 gene deletion was found to be viable but lethal in all other eukaryotes, raising the question to which extent the viability of the POL32 deletion in S. cerevisiae was species specific. To address this issue, we inactivated the POL32 gene in 10 evolutionary close or distant S. cerevisiae strains and found that POL32 was either essential (3 strains including SK1), non-essential (5 strains including the reference S288C strain) or confers a slow-growth phenotype (2 strains). Whole-genome sequencing of S288C/SK1 pol32∆ meiotic segregants identified the lethal/suppressor effect of the single Pol31-C43Y polymorphism. Consistently, the introduction of the Pol31-43C allele in the SK1 and West African (WA) pol32∆ mutants was sufficient to restore cell viability and wild-type growth upon introduction of two copies of POL31-43C in the SK1 haploid strain. Reciprocally, introduction of the SK1 POL31-43Y allele in the S288C pol32∆ mutant was lethal. Sequence analyses of the POL31 polymorphisms in the 1,011 yeasts genome dataset correlates with the strict occurrence of the POL31-43Y allele in the yeast African palm wine clade. Differently, the single Pol31-E400G polymorphism confers pol32∆ lethality in the Malaysian strain. In the yeast two-hybrid assay, we observed a weakened interaction between Pol3 and Pol31-43Y versus Pol31-43C suggesting an insufficient level of the Polδ holoenzyme stability/activity. Thus, the enigmatic non-essentiality of Pol32 in S. cerevisiae results from single Pol31 amino acid polymorphism and is clade rather than species specific.
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Affiliation(s)
- S Loeillet
- Institut Curie Research Center, CNRS UMR3244, PSL Research University, 26 rue d'Ulm, 75248 Paris Cedex 05, France
| | - A Nicolas
- Institut Curie Research Center, CNRS UMR3244, PSL Research University, 26 rue d'Ulm, 75248 Paris Cedex 05, France; IRCAN, CNRS UMR7284, INSERM U1081, Université Côte d'Azur, 28 avenue de Valombrose, 06107 Nice, France.
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4
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Balsa LM, Rodriguez MR, Ferraresi-Curotto V, Parajón-Costa BS, Gonzalez-Baró AC, León IE. Finding New Molecular Targets of Two Copper(II)-Hydrazone Complexes on Triple-Negative Breast Cancer Cells Using Mass-Spectrometry-Based Quantitative Proteomics. Int J Mol Sci 2023; 24:ijms24087531. [PMID: 37108690 PMCID: PMC10139133 DOI: 10.3390/ijms24087531] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 04/29/2023] Open
Abstract
Breast cancer is the most common cancer in women, with a high incidence estimated to reach 2.3 million by 2030. Triple-Negative Breast Cancer (TNBC) is the greatest invasive class of breast cancer with a poor prognosis, due to the side-effects exerted by the chemotherapy used and the low effectivity of novel treatments. In this sense, copper compounds have shown to be potentially effective as antitumor agents, attracting increasing interest as alternatives to the usually employed platinum-derived drugs. Therefore, the aim of this work is to identify differentially expressed proteins in MDA-MB-231 cells exposed to two copper(II)-hydrazone complexes using label-free quantitative proteomics and functional bioinformatics strategies to identify the molecular mechanisms through which these copper complexes exert their antitumoral effect in TNBC cells. Both copper complexes increased proteins involved in endoplasmic reticulum stress and unfolded protein response, as well as the downregulation of proteins related to DNA replication and repair. One of the most relevant anticancer mechanisms of action found for CuHL1 and CuHL2 was the down-regulation of gain-of-function-mutant p53. Moreover, we found a novel and interesting effect for a copper metallodrug, which was the down-regulation of proteins related to lipid synthesis and metabolism that could lead to a beneficial decrease in lipid levels.
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Affiliation(s)
- Lucia M Balsa
- CEQUINOR (UNLP, CCT-CONICET La Plata, Asociado a CIC), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata 1900, Argentina
| | - María R Rodriguez
- CEQUINOR (UNLP, CCT-CONICET La Plata, Asociado a CIC), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata 1900, Argentina
| | - Verónica Ferraresi-Curotto
- Instituto de Física La Plata, IFLP (UNLP, CCT-CONICET La Plata), Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata 1900, Argentina
| | - Beatriz S Parajón-Costa
- CEQUINOR (UNLP, CCT-CONICET La Plata, Asociado a CIC), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata 1900, Argentina
| | - Ana C Gonzalez-Baró
- CEQUINOR (UNLP, CCT-CONICET La Plata, Asociado a CIC), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata 1900, Argentina
| | - Ignacio E León
- CEQUINOR (UNLP, CCT-CONICET La Plata, Asociado a CIC), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata 1900, Argentina
- Cátedra de Fisiopatología, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata 1900, Argentina
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5
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Zakharenko AL, Malakhova AA, Dyrkheeva NS, Okorokova LS, Medvedev SP, Zakian SM, Kabilov MR, Tupikin AA, Lavrik OI. PARP1 Gene Knockout Suppresses Expression of DNA Base Excision Repair Genes. DOKL BIOCHEM BIOPHYS 2023; 508:6-11. [PMID: 36653586 PMCID: PMC10042944 DOI: 10.1134/s1607672922700028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 01/20/2023]
Abstract
The effect of PARP1 knockout in HEK293 cells on the gene expression of DNA base excision repair (BER) proteins was studied. It was shown that the expression of all differentially expressed genes (DEGs) of BER was reduced by knockout. The expression of the DNA glycosylase gene NEIL1, which is considered to be one of the common "hubs" for binding BER proteins, has changed the most. The expression of genes of auxiliary subunits of DNA polymerases δ and ε is also significantly reduced. The PARP1 gene knockout cell line obtained is an adequate cell model for studying the activity of the BER process in the absence of PARP1 and testing drugs aimed at inhibiting repair processes. It has been found for the first time that knockout of the PARP1 gene results in a significant change in the level of expression of proteins responsible for ribosome biogenesis and the functioning of the proteasome.
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Affiliation(s)
- A L Zakharenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A A Malakhova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Federal Research Centre Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Meshalkin National Medical Research Center of the Ministry of Health of the Russian Federation, Novosibirsk, Russia
| | - N S Dyrkheeva
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | | | - S P Medvedev
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Federal Research Centre Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Meshalkin National Medical Research Center of the Ministry of Health of the Russian Federation, Novosibirsk, Russia
| | - S M Zakian
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Federal Research Centre Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.,Meshalkin National Medical Research Center of the Ministry of Health of the Russian Federation, Novosibirsk, Russia
| | - M R Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A A Tupikin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - O I Lavrik
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
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6
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Yang D, Alphey MS, MacNeill SA. Non-canonical binding of the Chaetomium thermophilum PolD4 N-terminal PIP motif to PCNA involves Q-pocket and compact 2-fork plug interactions but no 3 10 helix. FEBS J 2023; 290:162-175. [PMID: 35942639 PMCID: PMC10087552 DOI: 10.1111/febs.16590] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/04/2022] [Accepted: 08/08/2022] [Indexed: 01/14/2023]
Abstract
DNA polymerase δ (Pol δ) is a key enzyme for the maintenance of genome integrity in eukaryotic cells, acting in concert with the sliding clamp processivity factor PCNA (proliferating cell nuclear antigen). Three of the four subunits of human Pol δ interact directly with the PCNA homotrimer via a short, conserved protein sequence known as a PCNA interacting protein (PIP) motif. Here, we describe the identification of a PIP motif located towards the N terminus of the PolD4 subunit of Pol δ (equivalent to human p12) from the thermophilic filamentous fungus Chaetomium thermophilum and present the X-ray crystal structure of the corresponding peptide bound to PCNA at 2.45 Å. Like human p12, the fungal PolD4 PIP motif displays non-canonical binding to PCNA. However, the structures of the human p12 and fungal PolD4 PIP motif peptides are quite distinct, with the fungal PolD4 PIP motif lacking the 310 helical segment that characterises most previously identified PIP motifs. Instead, the fungal PolD4 PIP motif binds PCNA via conserved glutamine that inserts into the Q-pocket on the surface of PCNA and with conserved leucine and phenylalanine sidechains forming a compact 2-fork plug that inserts into the hydrophobic pocket on PCNA. Despite the unusual binding mode of the fungal PolD4, isothermal calorimetry (ITC) measurements show that its affinity for PCNA is similar to that of its human orthologue. These observations add to a growing body of information on how diverse proteins interact with PCNA and highlight how binding modes can vary significantly between orthologous PCNA partner proteins.
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Affiliation(s)
- Dongxiao Yang
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, UK
| | - Magnus S Alphey
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, UK
| | - Stuart A MacNeill
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, UK
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7
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Gu X, Dai Q, Du P, Li N, Li J, Zeng S, Peng S, Tang S, Wang L, Zhou Z. Pold4 is dispensable for mouse development, DNA replication and DNA repair. Gene X 2022; 851:147029. [DOI: 10.1016/j.gene.2022.147029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/09/2022] [Accepted: 10/31/2022] [Indexed: 11/09/2022] Open
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8
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Scrutinizing Deleterious Nonsynonymous SNPs and Their Effect on Human POLD1 Gene. Genet Res (Camb) 2022; 2022:1740768. [PMID: 35620275 PMCID: PMC9117041 DOI: 10.1155/2022/1740768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/17/2022] [Accepted: 04/08/2022] [Indexed: 11/17/2022] Open
Abstract
POLD1 (DNA polymerase delta 1, catalytic subunit) is a protein-coding gene that encodes the large catalytic subunit (POLD1/p125) of the DNA polymerase delta (Polδ) complex. The consequence of missense or nonsynonymous SNPs (nsSNPs), which occur in the coding region of a specific gene, is the replacement of single amino acid. It may also change the structure, stability, and/or functions of the protein. Mutation in the POLD1 gene is associated with autosomal dominant predisposition to colonic adenomatous polyps, colon cancer, endometrial cancer (EDMC), breast cancer, and brain tumors. These de novo mutations in the POLD1 gene also result in autosomal dominant MDPL syndrome (mandibular hypoplasia, deafness, progeroid features, and lipodystrophy). In this study, genetic variations of POLD1 which may affect the structure and/or function were analyzed using different types of bioinformatics tools. A total of 17038 nsSNPs for POLD1 were collected from the NCBI database, among which 1317 were missense variants. Out of all missense nsSNPs, 28 were found to be deleterious functionally and structurally. Among these deleterious nsSNPs, 23 showed a conservation scale of >5, 2 were predicted to be associated with binding site formation, and one acted as a posttranslational modification site. All of them were involved in coil, extracellular structures, or helix formation, and some cause the change in size, charge, and hydrophobicity.
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9
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Fuchs J, Cheblal A, Gasser SM. Underappreciated Roles of DNA Polymerase δ in Replication Stress Survival. Trends Genet 2021; 37:476-487. [PMID: 33608117 DOI: 10.1016/j.tig.2020.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 01/06/2023]
Abstract
Recent structural analysis of Fe-S centers in replication proteins and insights into the structure and function of DNA polymerase δ (DNA Pol δ) subunits have shed light on the key role played by this polymerase at replication forks under stress. The sequencing of cancer genomes reveals multiple point mutations that compromise the activity of POLD1, the DNA Pol δ catalytic subunit, whereas the loci encoding the accessory subunits POLD2 and POLD3 are amplified in a very high proportion of human tumors. Consistently, DNA Pol δ is key for the survival of replication stress and is involved in multiple long-patch repair pathways. Synthetic lethality arises from compromising the function and availability of the noncatalytic subunits of DNA Pol δ under conditions of replication stress, opening the door to novel therapies.
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Affiliation(s)
- Jeannette Fuchs
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Anais Cheblal
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland; Faculty of Sciences, University of Basel, Klingelbergstrasse 90, CH-4056 Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland; Faculty of Sciences, University of Basel, Klingelbergstrasse 90, CH-4056 Basel, Switzerland.
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10
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Matsumoto Y, Brooks RC, Sverzhinsky A, Pascal JM, Tomkinson AE. Dynamic DNA-bound PCNA complexes co-ordinate Okazaki fragment synthesis, processing and ligation. J Mol Biol 2020; 432:166698. [PMID: 33157085 DOI: 10.1016/j.jmb.2020.10.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 10/07/2020] [Accepted: 10/27/2020] [Indexed: 11/28/2022]
Abstract
More than a million Okazaki fragments are synthesized, processed and joined during replication of the human genome. After synthesis of an RNA-DNA oligonucleotide by DNA polymerase α holoenzyme, proliferating cell nuclear antigen (PCNA), a homotrimeric DNA sliding clamp and polymerase processivity factor, is loaded onto the primer-template junction by replication factor C (RFC). Although PCNA interacts with the enzymes DNA polymerase δ (Pol δ), flap endonuclease 1 (FEN1) and DNA ligase I (LigI) that complete Okazaki fragment processing and joining, it is not known how the activities of these enzymes are coordinated. Here we describe a novel interaction between Pol δ and LigI that is critical for Okazaki fragment joining in vitro. Both LigI and FEN1 associate with PCNA-Pol δ during gap-filling synthesis, suggesting that gap-filling synthesis is carried out by a complex of PCNA, Pol δ, FEN1 and LigI. Following ligation, PCNA and LigI remain on the DNA, indicating that Pol δ and FEN1 dissociate during 5' end processing and that LigI engages PCNA at the DNA nick generated by FEN1 and Pol δ. Thus, dynamic PCNA complexes coordinate Okazaki fragment synthesis and processing with PCNA and LigI forming a terminal structure of two linked protein rings encircling the ligated DNA.
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Affiliation(s)
- Yoshihiro Matsumoto
- Departments of Internal Medicine, Molecular Genetics and Microbiology and the University of New Mexico Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131, United States
| | - Rhys C Brooks
- Departments of Internal Medicine, Molecular Genetics and Microbiology and the University of New Mexico Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131, United States
| | - Aleksandr Sverzhinsky
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - John M Pascal
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Alan E Tomkinson
- Departments of Internal Medicine, Molecular Genetics and Microbiology and the University of New Mexico Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131, United States.
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11
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Oh DY, Matsumoto Y, Kitajiri SI, Kim NKD, Kim MY, Kim AR, Lee M, Lee C, Tomkinson AE, Katsuno T, Kim SY, Shin HW, Han JH, Lee S, Park WY, Choi BY. POLD1 variants leading to reduced polymerase activity can cause hearing loss without syndromic features. Hum Mutat 2020; 41:913-920. [PMID: 31944473 DOI: 10.1002/humu.23984] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 12/17/2019] [Accepted: 01/13/2020] [Indexed: 11/08/2022]
Abstract
DNA polymerase δ, whose catalytic subunit is encoded by POLD1, is responsible for synthesizing the lagging strand of DNA. Single heterozygous POLD1 mutations in domains with polymerase and exonuclease activities have been reported to cause syndromic deafness as a part of multisystem metabolic disorder or predisposition to cancer. However, the phenotypes of diverse combinations of POLD1 genotypes have not been elucidated in humans. We found that five members of a multiplex family segregating autosomal recessive nonsyndromic sensorineural hearing loss (NS-SNHL) have revealed novel compound heterozygous POLD1 variants (p.Gly1100Arg and a presumptive null function variant, p.Ser197Hisfs*54). The recombinant p.Gly1100Arg polymerase δ showed a reduced polymerase activity by 30-40%, but exhibited normal exonuclease activity. The polymerase activity in cell extracts from the affected subject carrying the two POLD1 mutant alleles was about 33% of normal controls. We suggest that significantly decreased polymerase δ activity, but not a complete absence, with normal exonuclease activity could lead to NS-SNHL.
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Affiliation(s)
- Doo-Yi Oh
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Yoshihiro Matsumoto
- Departments of Internal Medicine and Molecular Genetics and Microbiology, and University of New Mexico Cancer Center, University of New Mexico, Albuquerque, New Mexico.,Department of Environmental Biology, Chubu University College of Bioscience and Biotechnology, Kasugai, Aichi, Japan
| | - Shin-Ichiro Kitajiri
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Nayoung K D Kim
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea
| | - Min Young Kim
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Ah Reum Kim
- Department of Otorhinolaryngology, Seoul National University Hospital, College of Medicine, Seoul National University, Seoul, Korea
| | - Mingyu Lee
- Department of Pharmacology, Seoul National University College of Medicine, Seoul, Korea.,Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Korea
| | - Chung Lee
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea.,Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Seoul, Korea
| | - Alan E Tomkinson
- Departments of Internal Medicine and Molecular Genetics and Microbiology, and University of New Mexico Cancer Center, University of New Mexico, Albuquerque, New Mexico
| | - Tatsuya Katsuno
- Department of Otolaryngology-Head and Neck Surgery, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - So Young Kim
- Department of Otorhinolaryngology, Seoul National University Hospital, College of Medicine, Seoul National University, Seoul, Korea
| | - Hyun-Woo Shin
- Department of Otorhinolaryngology, Seoul National University Hospital, College of Medicine, Seoul National University, Seoul, Korea.,Department of Pharmacology, Seoul National University College of Medicine, Seoul, Korea.,Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, Korea
| | - Jin Hee Han
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Seungmin Lee
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Woong-Yang Park
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea.,Department of Molecular Cell Biology, School of Medicine, Sungkyunkwan University, Seoul, Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, Korea
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12
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Xu Q, Hu C, Zhu Y, Wang K, Lal B, Li L, Tang J, Wei S, Huang G, Xia S, Lv S, Laterra J, Jiang Y, Li Y. ShRNA-based POLD2 expression knockdown sensitizes glioblastoma to DNA-Damaging therapeutics. Cancer Lett 2020; 482:126-135. [PMID: 31954770 DOI: 10.1016/j.canlet.2020.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 01/08/2020] [Accepted: 01/13/2020] [Indexed: 10/25/2022]
Abstract
Glioblastoma (GBM) has limited therapeutic options. DNA repair mechanisms contribute GBM cells to escape therapies and re-establish tumor growth. Multiple studies have shown that POLD2 plays a critical role in DNA replication, DNA repair and genomic stability. We demonstrate for the first time that POLD2 is highly expressed in human glioma specimens and that expression correlates with poor patient survival. siRNA or shRNA POLD2 inhibited GBM cell proliferation, cell cycle progression, invasiveness, sensitized GBM cells to chemo/radiation-induced cell death and reversed the cytoprotective effects of EGFR signaling. Conversely, forced POLD2 expression was found to induce GBM cell proliferation, colony formation, invasiveness and chemo/radiation resistance. POLD2 expression associated with stem-like cell subsets (CD133+ and SSEA-1+ cells) and positively correlated with Sox2 expression in clinical specimens. Its expression was induced by Sox2 and inhibited by the forced differentiation of GBM neurospheres. shRNA-POLD2 modestly inhibited GBM neurosphere-derived orthotopic xenografts growth, when combined with radiation, dramatically inhibited xenograft growth in a cooperative fashion. These novel findings identify POLD2 as a new potential therapeutic target for enhancing GBM response to current standard of care therapeutics.
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Affiliation(s)
- Qingfu Xu
- Department of Neurosurgery, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, 510623, PR China; Department of Neurosurgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, PR China; Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA; Department of Neurology, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA
| | - Chengchen Hu
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA; Department of Neurology, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA
| | - Yan Zhu
- Department of Ultrasonography, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, 510623, PR China; Department of Obstetrics and Gynecology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, PR China
| | - Kimberly Wang
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA
| | - Bachuchu Lal
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA
| | - Lichao Li
- Department of Neurosurgery, The First Hospital of Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Junhai Tang
- Department of Neurosurgery, Third Military Medical University, Chongqing, 400037, PR China
| | - Shuang Wei
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA
| | - Guohao Huang
- Department of Neurosurgery, Third Military Medical University, Chongqing, 400037, PR China
| | - Shuli Xia
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA; Department of Neurology, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA
| | - Shengqing Lv
- Department of Neurosurgery, Third Military Medical University, Chongqing, 400037, PR China
| | - John Laterra
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA; Department of Neurology, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA; Department of Oncology, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA; Department of Neuroscience, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA
| | - Yugang Jiang
- Department of Neurosurgery, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, PR China
| | - Yunqing Li
- Hugo W. Moser Research Institute at Kennedy Krieger, 707 N. Broadway, Baltimore, MD, 21205, USA; Department of Neurology, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, MD, 21287, USA.
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13
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Jozwiakowski SK, Kummer S, Gari K. Human DNA polymerase delta requires an iron-sulfur cluster for high-fidelity DNA synthesis. Life Sci Alliance 2019; 2:2/4/e201900321. [PMID: 31278166 PMCID: PMC6613617 DOI: 10.26508/lsa.201900321] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 01/10/2023] Open
Abstract
The iron–sulfur cluster in human DNA polymerase delta has an impact on DNA polymerase and exonuclease activities and can hence influence the fidelity of DNA synthesis. Replication of eukaryotic genomes relies on the family B DNA polymerases Pol α, Pol δ, and Pol ε. All of these enzymes coordinate an iron–sulfur (FeS) cluster, but the function of this cofactor has remained largely unclear. Here, we show that the FeS cluster in the catalytic subunit of human Pol δ is coordinated by four invariant cysteines of the C-terminal CysB motif. FeS cluster loss causes a partial destabilisation of the four-subunit enzyme, a defect in double-stranded DNA binding, and compromised polymerase and exonuclease activities. Importantly, complex stability, DNA binding, and enzymatic activities are restored in the presence of proliferating cell nuclear antigen. We further show that also more subtle changes to the FeS cluster-binding pocket that do not abolish FeS cluster binding can have repercussions on the distant exonuclease domain and render the enzyme error-prone. Our data hence suggest that the FeS cluster in human Pol δ is an important co-factor that despite its C-terminal location has an impact on both DNA polymerase and exonuclease activities, and can influence the fidelity of DNA synthesis.
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Affiliation(s)
| | - Sandra Kummer
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Kerstin Gari
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
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14
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Gao S, Song Q, Liu J, Zhang X, Ji X, Wang P. E2F1 mediates the downregulation of POLD1 in replicative senescence. Cell Mol Life Sci 2019; 76:2833-2850. [PMID: 30895337 PMCID: PMC6588650 DOI: 10.1007/s00018-019-03070-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 03/10/2019] [Accepted: 03/13/2019] [Indexed: 12/21/2022]
Abstract
POLD1, the catalytic subunit of DNA Pol δ, plays an important role in DNA synthesis and DNA damage repair, and POLD1 is downregulated in replicative senescence and mediates cell aging. However, the mechanisms of age-related downregulation of POLD1 expression have not been elucidated. In this study, four potential CpG islands in the POLD1 promoter were found, and the methylation levels of the POLD1 promoter were increased in aging 2BS cells, WI-38 cells and peripheral blood lymphocytes, especially at a single site, CpG 36, in CpG island 3. Then, the transcription factor E2F1 was observed to bind to these sites. The binding affinity of E2F1 for the POLD1 promoter was found to show age-related attenuation and was confirmed to be positively regulated by the E2F1 level and negatively regulated by POLD1 promoter methylation. Moreover, cell senescence characteristics were observed in the cells transfected with shRNA-E2F1 and could contribute to the downregulation of POLD1 induced by the E2F1 decline. Collectively, these results indicated that the attenuation of the binding affinity of E2F1 for the POLD1 promoter, mediated by an age-related decline in E2F1 and increased methylation of CpG island 3, downregulates POLD1 expression in aging.
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Affiliation(s)
- Shichao Gao
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing, 100053, People's Republic of China
| | - Qiao Song
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing, 100053, People's Republic of China
| | - Jing Liu
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing, 100053, People's Republic of China
| | - Xiaomin Zhang
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing, 100053, People's Republic of China
| | - Xunming Ji
- Beijing Institute of Brain Disorders, Capital Medical University, Beijing, 100053, People's Republic of China
| | - Peichang Wang
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing, 100053, People's Republic of China.
- Beijing Institute of Brain Disorders, Capital Medical University, Beijing, 100053, People's Republic of China.
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15
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Qin Q, Tan Q, Li J, Yang W, Lian B, Mo Q, Wei C. Elevated expression of POLD1 is associated with poor prognosis in breast cancer. Oncol Lett 2018; 16:5591-5598. [PMID: 30344713 PMCID: PMC6176253 DOI: 10.3892/ol.2018.9392] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 04/16/2018] [Indexed: 01/02/2023] Open
Abstract
Polymerase δ catalytic subunit gene 1 (POLD1) may serve an important function in the development of tumors. However, its role in breast cancer remains unclear. The aim of the present study was to observe the expression and the function of POLD1 in breast cancer. A total of 84 patients with invasive breast carcinoma were recruited between 2011 and 2013. The expression of POLD1 was detected in paired tumor and adjacent normal tissues. Gene expression level of POLD1 was assessed using reverse transcription quantitative polymerase chain reaction. The protein expression of POLD1 was assessed using western blot analysis. The association between the clinicopathological features of patients with breast cancer and POLD1 expression was analyzed using a χ2 test. Disease-free survival (DFS) was analyzed using Kaplan-Meier method, and Cox regression analysis was performed to investigate clinicopathological significance of POLD1 expression. Additionally, the effects of POLD1 in regulating cell cycle and proliferation of MCF-7 cells were evaluated in vitro. The results demonstrated that gene and protein expression levels of POLD1 were significantly elevated in breast cancer tissues compared with those in adjacent normal tissues. Increased expression of POLD1 was significantly associated with positive lymph node status (P=0.028), histological grade (P=0.025), p53 status (P<0.001) and ki-67 index (P=0.020). Survival analysis demonstrated that increased expression of POLD1 was associated with poor DFS (P=0.033). Additionally, increased expression of POLD1 was associated with shorter DFS at early-stage (P=0.037), late-stage cases (P=0.023) and with the presence of triple-negative tumors (TNBC; P=0.049). Multivariate analysis revealed that POLD1 may be used as an independent prognostic factor in patients with breast cancer. In vitro studies revealed that downregulation of POLD1 suppressed cell cycle progression and proliferation in MCF-7 cells. In conclusion, POLD1 may be considered as a potential prognostic marker for invasive breast carcinoma.
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Affiliation(s)
- Qinghong Qin
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Qixing Tan
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Jinyuan Li
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Weiping Yang
- Department of Ultrasound Diagnosis, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Bin Lian
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Qinguo Mo
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
| | - Changyuan Wei
- Department of Breast Surgery, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China
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16
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Lee MYWT, Wang X, Zhang S, Zhang Z, Lee EYC. Regulation and Modulation of Human DNA Polymerase δ Activity and Function. Genes (Basel) 2017; 8:genes8070190. [PMID: 28737709 PMCID: PMC5541323 DOI: 10.3390/genes8070190] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/07/2017] [Accepted: 07/11/2017] [Indexed: 12/28/2022] Open
Abstract
This review focuses on the regulation and modulation of human DNA polymerase δ (Pol δ). The emphasis is on the mechanisms that regulate the activity and properties of Pol δ in DNA repair and replication. The areas covered are the degradation of the p12 subunit of Pol δ, which converts it from a heterotetramer (Pol δ4) to a heterotrimer (Pol δ3), in response to DNA damage and also during the cell cycle. The biochemical mechanisms that lead to degradation of p12 are reviewed, as well as the properties of Pol δ4 and Pol δ3 that provide insights into their functions in DNA replication and repair. The second focus of the review involves the functions of two Pol δ binding proteins, polymerase delta interaction protein 46 (PDIP46) and polymerase delta interaction protein 38 (PDIP38), both of which are multi-functional proteins. PDIP46 is a novel activator of Pol δ4, and the impact of this function is discussed in relation to its potential roles in DNA replication. Several new models for the roles of Pol δ3 and Pol δ4 in leading and lagging strand DNA synthesis that integrate a role for PDIP46 are presented. PDIP38 has multiple cellular localizations including the mitochondria, the spliceosomes and the nucleus. It has been implicated in a number of cellular functions, including the regulation of specialized DNA polymerases, mitosis, the DNA damage response, mouse double minute 2 homolog (Mdm2) alternative splicing and the regulation of the NADPH oxidase 4 (Nox4).
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Affiliation(s)
- Marietta Y W T Lee
- Department Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
| | - Xiaoxiao Wang
- Department Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
| | - Sufang Zhang
- Department Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
| | - Zhongtao Zhang
- Department Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
| | - Ernest Y C Lee
- Department Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
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17
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GenePANDA-a novel network-based gene prioritizing tool for complex diseases. Sci Rep 2017; 7:43258. [PMID: 28252032 PMCID: PMC5333103 DOI: 10.1038/srep43258] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/23/2017] [Indexed: 02/08/2023] Open
Abstract
Here we describe GenePANDA, a novel network-based tool for prioritizing candidate disease genes. GenePANDA assesses whether a gene is likely a candidate disease gene based on its relative distance to known disease genes in a functional association network. A unique feature of GenePANDA is the introduction of adjusted network distance derived by normalizing the raw network distance between two genes with their respective mean raw network distance to all other genes in the network. The use of adjusted network distance significantly improves GenePANDA’s performance on prioritizing complex disease genes. GenePANDA achieves superior performance over five previously published algorithms for prioritizing disease genes. Finally, GenePANDA can assist in prioritizing functionally important SNPs identified by GWAS.
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18
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Wang X, Zhang S, Zheng R, Yue F, Lin SHS, Rahmeh AA, Lee EYC, Zhang Z, Lee MYWT. PDIP46 (DNA polymerase δ interacting protein 46) is an activating factor for human DNA polymerase δ. Oncotarget 2017; 7:6294-313. [PMID: 26819372 PMCID: PMC4868757 DOI: 10.18632/oncotarget.7034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 01/25/2016] [Indexed: 02/07/2023] Open
Abstract
PDIP46 (SKAR, POLDIP3) was discovered through its interaction with the p50 subunit of human DNA polymerase δ (Pol δ). Its functions in DNA replication are unknown. PDIP46 associates with Pol δ in cell extracts both by immunochemical and protein separation methods, as well as by ChIP analyses. PDIP46 also interacts with PCNA via multiple copies of a novel PCNA binding motif, the APIMs (AlkB homologue-2 PCNA-Interacting Motif). Sites for both p50 and PCNA binding were mapped to the N-terminal region containing the APIMs. Functional assays for the effects of PDIP46 on Pol δ activity on singly primed ssM13 DNA templates revealed that it is a novel and potent activator of Pol δ. The effects of PDIP46 on Pol δ in primer extension, strand displacement and synthesis through simple hairpin structures reveal a mechanism where PDIP46 facilitates Pol δ4 synthesis through regions of secondary structure on complex templates. In addition, evidence was obtained that PDIP46 is also capable of exerting its effects by a direct interaction with Pol δ, independent of PCNA. Mutation of the Pol δ and PCNA binding region resulted in a loss of PDIP46 functions. These studies support the view that PDIP46 is a novel accessory protein for Pol δ that is involved in cellular DNA replication. This raises the possibility that altered expression of PDIP46 or its mutation may affect Pol δ functions in vivo, and thereby be a nexus for altered genomic stability.
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Affiliation(s)
- Xiaoxiao Wang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Rong Zheng
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Fu Yue
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Szu Hua Sharon Lin
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Amal A Rahmeh
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Ernest Y C Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Zhongtao Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
| | - Marietta Y W T Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
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19
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POLD3 Is Haploinsufficient for DNA Replication in Mice. Mol Cell 2016; 63:877-83. [PMID: 27524497 DOI: 10.1016/j.molcel.2016.07.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 06/05/2016] [Accepted: 07/08/2016] [Indexed: 11/21/2022]
Abstract
The Pold3 gene encodes a subunit of the Polδ DNA polymerase complex. Pold3 orthologs are not essential in Saccharomyces cerevisiae or chicken DT40 cells, but the Schizosaccharomyces pombe ortholog is essential. POLD3 also has a specialized role in the repair of broken replication forks, suggesting that POLD3 activity could be particularly relevant for cancer cells enduring high levels of DNA replication stress. We report here that POLD3 is essential for mouse development and is also required for viability in adult animals. Strikingly, even Pold3(+/-) mice were born at sub-Mendelian ratios, and, of those born, some presented hydrocephaly and had a reduced lifespan. In cells, POLD3 deficiency led to replication stress and cell death, which were aggravated by the expression of activated oncogenes. Finally, we show that Pold3 deletion destabilizes all members of the Polδ complex, explaining its major role in DNA replication and the severe impact of its deficiency.
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20
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Abstract
The cellular replicating machine, or "replisome," is composed of numerous different proteins. The core replication proteins in all cell types include a helicase, primase, DNA polymerases, sliding clamp, clamp loader, and single-strand binding (SSB) protein. The core eukaryotic replisome proteins evolved independently from those of bacteria and thus have distinct architectures and mechanisms of action. The core replisome proteins of the eukaryote include: an 11-subunit CMG helicase, DNA polymerase alpha-primase, leading strand DNA polymerase epsilon, lagging strand DNA polymerase delta, PCNA clamp, RFC clamp loader, and the RPA SSB protein. There are numerous other proteins that travel with eukaryotic replication forks, some of which are known to be involved in checkpoint regulation or nucleosome handling, but most have unknown functions and no bacterial analogue. Recent studies have revealed many structural and functional insights into replisome action. Also, the first structure of a replisome from any cell type has been elucidated for a eukaryote, consisting of 20 distinct proteins, with quite unexpected results. This review summarizes the current state of knowledge of the eukaryotic core replisome proteins, their structure, individual functions, and how they are organized at the replication fork as a machine.
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Affiliation(s)
- D Zhang
- The Rockefeller University, New York, NY, United States
| | - M O'Donnell
- The Rockefeller University, New York, NY, United States; Howard Hughes Medical Institute, The Rockefeller University, New York, NY, United States.
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21
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Stodola JL, Stith CM, Burgers PM. Proficient Replication of the Yeast Genome by a Viral DNA Polymerase. J Biol Chem 2016; 291:11698-705. [PMID: 27072134 DOI: 10.1074/jbc.m116.728741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Indexed: 11/06/2022] Open
Abstract
DNA replication in eukaryotic cells requires minimally three B-family DNA polymerases: Pol α, Pol δ, and Pol ϵ. Pol δ replicates and matures Okazaki fragments on the lagging strand of the replication fork. Saccharomyces cerevisiae Pol δ is a three-subunit enzyme (Pol3-Pol31-Pol32). A small C-terminal domain of the catalytic subunit Pol3 carries both iron-sulfur cluster and zinc-binding motifs, which mediate interactions with Pol31, and processive replication with the replication clamp proliferating cell nuclear antigen (PCNA), respectively. We show that the entire N-terminal domain of Pol3, containing polymerase and proofreading activities, could be effectively replaced by those from bacteriophage RB69, and could carry out chromosomal DNA replication in yeast with remarkable high fidelity, provided that adaptive mutations in the replication clamp PCNA were introduced. This result is consistent with the model that all essential interactions for DNA replication in yeast are mediated through the small C-terminal domain of Pol3. The chimeric polymerase carries out processive replication with PCNA in vitro; however, in yeast, it requires an increased involvement of the mutagenic translesion DNA polymerase ζ during DNA replication.
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Affiliation(s)
- Joseph L Stodola
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Carrie M Stith
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Peter M Burgers
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
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22
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Vasuvat J, Montree A, Moonsom S, Leartsakulpanich U, Petmitr S, Focher F, Wright GE, Chavalitshewinkoon-Petmitr P. Biochemical and functional characterization of Plasmodium falciparum DNA polymerase δ. Malar J 2016; 15:116. [PMID: 26911594 PMCID: PMC4766629 DOI: 10.1186/s12936-016-1166-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/11/2016] [Indexed: 12/05/2022] Open
Abstract
Background Emergence of drug-resistant Plasmodium falciparum has created an urgent need for new drug targets. DNA polymerase δ is an essential enzyme required for chromosomal DNA replication and repair, and therefore may be a potential target for anti-malarial drug development. However, little is known of the characteristics and function of this P. falciparum enzyme. Methods The coding sequences of DNA polymerase δ catalytic subunit (PfPolδ-cat), DNA polymerase δ small subunit (PfPolδS) and proliferating cell nuclear antigen (PfPCNA) from chloroquine- and pyrimethamine-resistant P. falciparum strain K1 were amplified, cloned into an expression vector and expressed in Escherichia coli. The recombinant proteins were analysed by SDS-PAGE and identified by LC–MS/MS. PfPolδ-cat was biochemically characterized. The roles of PfPolδS and PfPCNA in PfPolδ-cat function were investigated. In addition, inhibitory effects of 11 compounds were tested on PfPolδ-cat activity and on in vitro parasite growth using SYBR Green I assay. Results The purified recombinant protein PfPolδ-cat, PfPolδS and PfPCNA showed on SDS-PAGE the expected size of 143, 57 and 34 kDa, respectively. Predicted amino acid sequence of the PfPolδ-cat and PfPolδS had 59.2 and 24.7 % similarity respectively to that of the human counterpart. The PfPolδ-cat possessed both DNA polymerase and 3′–5′ exonuclease activities. It used both Mg2+ and Mn2+ as cofactors and was inhibited by high KCl salt (>200 mM). PfPolδS stimulated PfPolδ-cat activity threefolds and up to fourfolds when PfPCNA was included in the assay. Only two compounds were potent inhibitors of PfPolδ-cat, namely, butylphenyl-dGTP (BuPdGTP; IC50 of 38 µM) and 7-acetoxypentyl-(3, 4 dichlorobenzyl) guanine (7-acetoxypentyl-DCBG; IC50 of 55 µM). The latter compound showed higher inhibition on parasite growth (IC50 of 4.1 µM). Conclusions Recombinant PfPolδ-cat, PfPolδS and PfPCNA were successfully expressed and purified. PfPolS and PfPCNA increased DNA polymerase activity of PfPolδ-cat. The high sensitivity of PfPolδ to BuPdGTP can be used to differentiate parasite enzyme from mammalian and human counterparts. Interestingly, 7-acetoxypentyl-DCBG showed inhibitory effects on both enzyme activity and parasite growth. Thus, 7-acetoxypentyl-DCBG is a potential candidate for future development of a new class of anti-malarial agents targeting parasite replicative DNA polymerase.
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Affiliation(s)
- Jitlada Vasuvat
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Atcha Montree
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Sangduen Moonsom
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Ubolsree Leartsakulpanich
- National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Pahonyothin Rd, Pathumthani, 12120, Thailand.
| | - Songsak Petmitr
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
| | | | - George E Wright
- GLSynthesis Inc., One Innovation Drive, Worcester, MA, 01605, USA.
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23
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Zhao H, Zhang S, Xu D, Lee MY, Zhang Z, Lee EY, Darzynkiewicz Z. Expression of the p12 subunit of human DNA polymerase δ (Pol δ), CDK inhibitor p21(WAF1), Cdt1, cyclin A, PCNA and Ki-67 in relation to DNA replication in individual cells. Cell Cycle 2015; 13:3529-40. [PMID: 25483089 DOI: 10.4161/15384101.2014.958910] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We recently reported that the p12 subunit of human DNA polymerase δ (Pol δ4) is degraded by CRL4(Cdt2) which regulates the licensing factor Cdt1 and p21(WAF1) during the G1 to S transition. Presently, we performed multiparameter laser scanning cytometric analyses of changes in levels of p12, Cdt1 and p21(WAF1), detected immunocytochemically in individual cells, vis-à-vis the initiation and completion of DNA replication. The latter was assessed by pulse-labeling A549 cells with the DNA precursor ethynyl-2'-deoxyribose (EdU). The loss of p12 preceded the initiation of DNA replication and essentially all cells incorporating EdU were p12 negative. Completion of DNA replication and transition to G2 phase coincided with the re-appearance and rapid rise of p12 levels. Similar to p12 a decline of p21(WAF1) and Cdt1 was seen at the end of G1 phase and all DNA replicating cells were p21(WAF1) and Cdt1 negative. The loss of p21(WAF1) preceded that of Cdt1 and p12 and the disappearance of the latter coincided with the onset of DNA replication. Loss of p12 leads to conversion of Pol δ4 to its trimeric form, Pol δ3, so that the results provide strong support to the notion that Pol δ3 is engaged in DNA replication during unperturbed progression through the S phase of cell cycle. Also assessed was a correlation between EdU incorporation, likely reflecting the rate of DNA replication in individual cells, and the level of expression of positive biomarkers of replication cyclin A, PCNA and Ki-67 in these cells. Of interest was the observation of stronger correlation between EdU incorporation and expression of PCNA (r = 0.73) than expression of cyclin A (r = 0.47) or Ki-67 (r = 0.47).
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Affiliation(s)
- Hong Zhao
- a Brander Cancer Research Institute; Department of Pathology; New York Medical College ; Valhalla , NY USA
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Song J, Hong P, Liu C, Zhang Y, Wang J, Wang P. Human POLD1 modulates cell cycle progression and DNA damage repair. BMC BIOCHEMISTRY 2015; 16:14. [PMID: 26087769 PMCID: PMC4471906 DOI: 10.1186/s12858-015-0044-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 06/05/2015] [Indexed: 11/22/2022]
Abstract
Background The activity of eukaryotic DNA polymerase delta (Pol δ) plays an essential role in genome stability through its effects on DNA replication and repair. The p125 catalytic subunit of Pol δ is encoded by POLD1 gene in human cells. To clarify biological functions of POLD1, we investigated the effects of POLD1 overexpression or downregulation on cell proliferation, cell cycle progression, DNA synthesis and oxidative DNA damage induced by H2O2. Methods HEK293 cells were transfected with POLD1 expression plasmid or shRNA, cell proliferation, cell cycle progression, and DNA synthesis in HEK293 cells were analyzed. Results HEK293 cells were transfected with POLD1 expression plasmid or shRNA. POLD1 downregulation by shRNA suppressed cell proliferation, cell cycle progression, and DNA synthesis in HEK293 cells. However, POLD1 overexpression had no significant effects on these processes. Finally, comet assay showed that POLD1 downregulation led to increased DNA damage. Conclusions Our results suggest that human POLD1 plays important role in the regulation of cell cycle progression and DNA damage repair.
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Affiliation(s)
- Jing Song
- Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China.
| | - Ping Hong
- Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China.
| | - Chengeng Liu
- Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China.
| | - Yueqi Zhang
- Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China.
| | - Jinling Wang
- Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China.
| | - Peichang Wang
- Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China.
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Tritto P, Palumbo V, Micale L, Marzulli M, Bozzetti MP, Specchia V, Palumbo G, Pimpinelli S, Berloco M. Loss of Pol32 in Drosophila melanogaster causes chromosome instability and suppresses variegation. PLoS One 2015; 10:e0120859. [PMID: 25826374 PMCID: PMC4380491 DOI: 10.1371/journal.pone.0120859] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 01/27/2015] [Indexed: 11/29/2022] Open
Abstract
Pol32 is an accessory subunit of the replicative DNA Polymerase δ and of the translesion Polymerase ζ. Pol32 is involved in DNA replication, recombination and repair. Pol32’s participation in high- and low-fidelity processes, together with the phenotypes arising from its disruption, imply multiple roles for this subunit within eukaryotic cells, not all of which have been fully elucidated. Using pol32 null mutants and two partial loss-of-function alleles pol32rd1 and pol32rds in Drosophila melanogaster, we show that Pol32 plays an essential role in promoting genome stability. Pol32 is essential to ensure DNA replication in early embryogenesis and it participates in the repair of mitotic chromosome breakage. In addition we found that pol32 mutantssuppress position effect variegation, suggesting a role for Pol32 in chromatin architecture.
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Affiliation(s)
- Patrizia Tritto
- Dipartimento di Biologia, Università degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy
| | - Valeria Palumbo
- Dipartimento di Biologia e Biotecnologie “C. Darwin”, Università degli Studi di Roma “La Sapienza”, 00185 Roma, Italy
| | - Lucia Micale
- IRCCS Casa Sollievo Della Sofferenza Hospital, 71013 San Giovanni Rotondo, Italy
| | - Marco Marzulli
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, United States of America
| | - Maria Pia Bozzetti
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy
| | - Valeria Specchia
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy
| | - Gioacchino Palumbo
- Dipartimento di Biologia, Università degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy
| | - Sergio Pimpinelli
- Istituto Pasteur—Fondazione Cenci Bolognetti and Dipartimento di Biologia e Biotecnologie “C. Darwin”, Università degli Studi di Roma “La Sapienza”, 00185 Roma, Italy
| | - Maria Berloco
- Dipartimento di Biologia, Università degli Studi di Bari “Aldo Moro”, 70125 Bari, Italy
- * E-mail:
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Doublié S, Zahn KE. Structural insights into eukaryotic DNA replication. Front Microbiol 2014; 5:444. [PMID: 25202305 PMCID: PMC4142720 DOI: 10.3389/fmicb.2014.00444] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/04/2014] [Indexed: 12/23/2022] Open
Abstract
Three DNA polymerases of the B family function at the replication fork in eukaryotic cells: DNA polymerases α, δ, and ε. DNA polymerase α, an heterotetramer composed of two primase subunits and two polymerase subunits, initiates replication. DNA polymerases δ and ε elongate the primers generated by pol α. The DNA polymerase from bacteriophage RB69 has served as a model for eukaryotic B family polymerases for some time. The recent crystal structures of pol δ, α, and ε revealed similarities but also a number of unexpected differences between the eukaryotic polymerases and their bacteriophage counterpart, and also among the three yeast polymerases. This review will focus on their shared structural elements as well as the features that are unique to each of these polymerases.
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Affiliation(s)
- Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont Burlington, VT, USA
| | - Karl E Zahn
- Department of Microbiology and Molecular Genetics, University of Vermont Burlington, VT, USA
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27
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Huang Q, Suzuki M, Zeng Y, Zhang H, Yang D, Lin H. Downregulation of POLD4 in Calu6 cells results in G1-S blockage through suppression of the Akt-Skp2-p27 pathway. Bioorg Med Chem Lett 2014; 24:1780-3. [PMID: 24618301 DOI: 10.1016/j.bmcl.2014.02.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 01/27/2014] [Accepted: 02/11/2014] [Indexed: 12/23/2022]
Abstract
Previously, we have shown that downregulation of POLD4 in lung cancer cells delays progression through the G1-S cell cycle transition and leads to increased genomic instability. To date however, detailed molecular mechanisms have not been elucidated to explain how this occurs. In the present study, we found that reduction in POLD4 by siRNA knockdown promoted downregulation of both p-Akt Ser473 and Skp2 as well as upregulation of p27. Furthermore, these protein expression levels were rescued when siRNA-resistant POLD4 was ectopically expressed in the knockdown cells. These data suggest that the POLD4 downregulation is associated with impaired Akt-Skp2-p27 pathway in lung cancer.
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Affiliation(s)
- Qinmiao Huang
- Department of Pulmonary Medicine, Second Affiliated Hospital of Fujian Medical University, Fujian, China.
| | - Motoshi Suzuki
- Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yiming Zeng
- Department of Pulmonary Medicine, Second Affiliated Hospital of Fujian Medical University, Fujian, China
| | - Huaping Zhang
- Department of Pulmonary Medicine, Second Affiliated Hospital of Fujian Medical University, Fujian, China
| | - Dongyong Yang
- Department of Pulmonary Medicine, Second Affiliated Hospital of Fujian Medical University, Fujian, China
| | - Huihuang Lin
- Department of Pulmonary Medicine, Second Affiliated Hospital of Fujian Medical University, Fujian, China
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28
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Ream DC, Murakami ST, Schmidt EE, Huang GH, Liang C, Friedberg I, Cheng XW. Comparative analysis of error-prone replication mononucleotide repeats across baculovirus genomes. Virus Res 2013; 178:217-25. [PMID: 24140718 DOI: 10.1016/j.virusres.2013.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 10/04/2013] [Accepted: 10/07/2013] [Indexed: 11/25/2022]
Abstract
Genome replication by the baculovirus DNA polymerase often generates errors in mononucleotide repeat (MNR) sequences due to replication slippage. This results in the inactivation of genes that affects different stages of the cell infection cycle. Here we mapped these MNRs in the 59 baculovirus genomes. We found that the MNR frequencies of baculovirus genomes are different and not correlated with the genome sizes. Although the average A/T content of baculoviruses is 58.67%, the A/T MNR frequency is significantly higher than that of the G/C MNRs. Furthermore, the A7/T7 MNRs are the most frequent of those we studied. Finally, MNR frequencies in different classes of baculovirus genes, such as immediate early genes, show differences between baculovirus genomes, suggesting that the distribution and frequency of different MNRs are unique to each baculovirus species or strain. Therefore, the results of this study can help select appropriate baculoviruses for the development of biological insecticides.
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Affiliation(s)
- David C Ream
- Department of Microbiology, Miami University, Oxford, OH, USA
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29
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Lee MYWT, Zhang S, Lin SHS, Wang X, Darzynkiewicz Z, Zhang Z, Lee EYC. The tail that wags the dog: p12, the smallest subunit of DNA polymerase δ, is degraded by ubiquitin ligases in response to DNA damage and during cell cycle progression. Cell Cycle 2013; 13:23-31. [PMID: 24300032 DOI: 10.4161/cc.27407] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
DNA polymerase δ (Pol δ) is a key enzyme in eukaryotic DNA replication. Human Pol δ is a heterotetramer whose p12 subunit is degraded in response to DNA damage, leading to the in vivo conversion of Pol δ4 to Pol δ3. Two E3 ubiquitin ligases, RNF8 and CRL4(Cdt2), participate in the DNA damage-induced degradation of p12. We discuss how these E3 ligases integrate the formation of Pol δ3 and ubiquitinated PCNA for DNA repair processes. CRL4(Cdt2) partially degrades p12 during normal cell cycle progression, thereby generating Pol δ3 during S phase. This novel finding extends the current view of the role of Pol δ3 in DNA repair and leads to the hypothesis that it participates in DNA replication. The coordinated regulation of licensing factors and Pol δ3 by CRL4(Cdt2) now opens new avenues for control of DNA replication. A parallel study of Pol δ4 and Pol δ3 in Okazaki fragment processing provides evidence for a role of Pol δ3 in DNA replication. We discuss several new perspectives of the role of the 2 forms of Pol δ in DNA replication and repair, as well the significance of the integration of p12 regulation in DNA repair and cell cycle progression.
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Affiliation(s)
- Marietta Y W T Lee
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla, NY USA
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla, NY USA
| | - Szu Hua Sharon Lin
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla, NY USA
| | - Xiaoxiao Wang
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla, NY USA
| | - Zbigniew Darzynkiewicz
- Department of Pathology; Brander Cancer Research Institute; New York Medical College; Valhalla, NY USA
| | - Zhongtao Zhang
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla, NY USA
| | - Ernest Y C Lee
- Department of Biochemistry and Molecular Biology; New York Medical College; Valhalla, NY USA
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30
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Lin SHS, Wang X, Zhang S, Zhang Z, Lee EY, Lee MY. Dynamics of enzymatic interactions during short flap human Okazaki fragment processing by two forms of human DNA polymerase δ. DNA Repair (Amst) 2013; 12:922-35. [PMID: 24035200 PMCID: PMC3825817 DOI: 10.1016/j.dnarep.2013.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 07/30/2013] [Accepted: 08/21/2013] [Indexed: 12/22/2022]
Abstract
Lagging strand DNA replication requires the concerted actions of DNA polymerase δ, Fen1 and DNA ligase I for the removal of the RNA/DNA primers before ligation of Okazaki fragments. To better understand this process in human cells, we have reconstituted Okazaki fragment processing by the short flap pathway in vitro with purified human proteins and oligonucleotide substrates. We systematically characterized the key events in Okazaki fragment processing: the strand displacement, Pol δ/Fen1 combined reactions for removal of the RNA/DNA primer, and the complete reaction with DNA ligase I. Two forms of human DNA polymerase δ were studied: Pol δ4 and Pol δ3, which represent the heterotetramer and the heterotrimer lacking the p12 subunit, respectively. Pol δ3 exhibits very limited strand displacement activity in contrast to Pol δ4, and stalls on encounter with a 5'-blocking oligonucleotide. Pol δ4 and Pol δ3 exhibit different characteristics in the Pol δ/Fen1 reactions. While Pol δ3 produces predominantly 1 and 2 nt cleavage products irrespective of Fen1 concentrations, Pol δ4 produces cleavage fragments of 1-10 nts at low Fen1 concentrations. Pol δ3 and Pol δ4 exhibit comparable formation of ligated products in the complete system. While both are capable of Okazaki fragment processing in vitro, Pol δ3 exhibits ideal characteristics for a role in Okazaki fragment processing. Pol δ3 readily idles and in combination with Fen1 produces primarily 1 nt cleavage products, so that nick translation predominates in the removal of the blocking strand, avoiding the production of longer flaps that require additional processing. These studies represent the first analysis of the two forms of human Pol δ in Okazaki fragment processing. The findings provide evidence for the novel concept that Pol δ3 has a role in lagging strand synthesis, and that both forms of Pol δ may participate in DNA replication in higher eukaryotic cells.
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Affiliation(s)
- Szu Hua Sharon Lin
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Xiaoxiao Wang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Zhongtao Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Ernest Y.C. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Marietta Y.W.T. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
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31
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Aze A, Zhou JC, Costa A, Costanzo V. DNA replication and homologous recombination factors: acting together to maintain genome stability. Chromosoma 2013; 122:401-13. [PMID: 23584157 DOI: 10.1007/s00412-013-0411-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/27/2013] [Accepted: 03/27/2013] [Indexed: 10/27/2022]
Abstract
Genome duplication requires the coordinated action of multiple proteins to ensure a fast replication with high fidelity. These factors form a complex called the Replisome, which is assembled onto the DNA duplex to promote its unwinding and to catalyze the polymerization of two new strands. Key constituents of the Replisome are the Cdc45-Mcm2-7-GINS helicase and the And1-Claspin-Tipin-Tim1 complex, which coordinate DNA unwinding with polymerase alpha-, delta-, and epsilon- dependent DNA polymerization. These factors encounter numerous obstacles, such as endogenous DNA lesions leading to template breakage and complex structures arising from intrinsic features of specific DNA sequences. To overcome these roadblocks, homologous recombination DNA repair factors, such as Rad51 and the Mre11-Rad50-Nbs1 complex, are required to ensure complete and faithful replication. Consistent with this notion, many of the genes involved in this process result in lethal phenotypes when inactivated in organisms with complex and large genomes. Here, we summarize the architectural and functional properties of the Replisome and propose a unified view of DNA replication and repair processes.
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Affiliation(s)
- Antoine Aze
- Clare Hall Laboratories, London Research Institute, South Mimms, Herts, EN63LD, UK
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32
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Abstract
In 1959, Arthur Kornberg was awarded the Nobel Prize for his work on the principles by which DNA is duplicated by DNA polymerases. Since then, it has been confirmed in all branches of life that replicative DNA polymerases require a single-stranded template to build a complementary strand, but they cannot start a new DNA strand de novo. Thus, they also depend on a primase, which generally assembles a short RNA primer to provide a 3'-OH that can be extended by the replicative DNA polymerase. The general principles that (1) a helicase unwinds the double-stranded DNA, (2) single-stranded DNA-binding proteins stabilize the single-stranded DNA, (3) a primase builds a short RNA primer, and (4) a clamp loader loads a clamp to (5) facilitate the loading and processivity of the replicative polymerase, are well conserved among all species. Replication of the genome is remarkably robust and is performed with high fidelity even in extreme environments. Work over the last decade or so has confirmed (6) that a common two-metal ion-promoted mechanism exists for the nucleotidyltransferase reaction that builds DNA strands, and (7) that the replicative DNA polymerases always act as a key component of larger multiprotein assemblies, termed replisomes. Furthermore (8), the integrity of replisomes is maintained by multiple protein-protein and protein-DNA interactions, many of which are inherently weak. This enables large conformational changes to occur without dissociation of replisome components, and also means that in general replisomes cannot be isolated intact.
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Affiliation(s)
- Erik Johansson
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden.
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33
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Identification of survival factors in LPS-stimulated anthrax lethal toxin tolerant RAW 264.7 cells through proteomic approach. BIOCHIP JOURNAL 2013. [DOI: 10.1007/s13206-013-7112-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Prindle MJ, Loeb LA. DNA polymerase delta in DNA replication and genome maintenance. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:666-82. [PMID: 23065663 PMCID: PMC3694620 DOI: 10.1002/em.21745] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 09/09/2012] [Accepted: 09/12/2012] [Indexed: 05/12/2023]
Abstract
The eukaryotic genome is in a constant state of modification and repair. Faithful transmission of the genomic information from parent to daughter cells depends upon an extensive system of surveillance, signaling, and DNA repair, as well as accurate synthesis of DNA during replication. Often, replicative synthesis occurs over regions of DNA that have not yet been repaired, presenting further challenges to genomic stability. DNA polymerase δ (pol δ) occupies a central role in all of these processes: catalyzing the accurate replication of a majority of the genome, participating in several DNA repair synthetic pathways, and contributing structurally to the accurate bypass of problematic lesions during translesion synthesis. The concerted actions of pol δ on the lagging strand, pol ϵ on the leading strand, associated replicative factors, and the mismatch repair (MMR) proteins results in a mutation rate of less than one misincorporation per genome per replication cycle. This low mutation rate provides a high level of protection against genetic defects during development and may prevent the initiation of malignancies in somatic cells. This review explores the role of pol δ in replication fidelity and genome maintenance.
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Affiliation(s)
- Marc J Prindle
- Department of Pathology, The Joseph Gottstien Memorial Cancer Research Laboratory, University of Washington, Seattle, WA 98195-7705, USA
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35
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Menezes MR, Sweasy JB. Mouse models of DNA polymerases. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:645-665. [PMID: 23001998 DOI: 10.1002/em.21731] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 08/01/2012] [Accepted: 08/07/2012] [Indexed: 06/01/2023]
Abstract
In 1956, Arthur Kornberg discovered the mechanism of the biological synthesis of DNA and was awarded the Nobel Prize in Physiology or Medicine in 1959 for this contribution, which included the isolation and characterization of Escherichia coli DNA polymerase I. Now there are 15 known DNA polymerases in mammalian cells that belong to four different families. These DNA polymerases function in many different cellular processes including DNA replication, DNA repair, and damage tolerance. Several biochemical and cell biological studies have provoked a further investigation of DNA polymerase function using mouse models in which polymerase genes have been altered using gene-targeting techniques. The phenotypes of mice harboring mutant alleles reveal the prominent role of DNA polymerases in embryogenesis, prevention of premature aging, and cancer suppression.
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Affiliation(s)
- Miriam R Menezes
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA
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36
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Lee MYWT, Zhang S, Lin SHS, Chea J, Wang X, LeRoy C, Wong A, Zhang Z, Lee EYC. Regulation of human DNA polymerase delta in the cellular responses to DNA damage. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:683-698. [PMID: 23047826 DOI: 10.1002/em.21743] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 06/01/2023]
Abstract
The p12 subunit of polymerase delta (Pol δ) is degraded in response to DNA damage induced by UV, alkylating agents, oxidative, and replication stresses. This leads to the conversion of the Pol δ4 holoenzyme to the heterotrimer, Pol δ3. We review studies that establish that Pol δ3 formation is an event that could have a major impact on cellular processes in genomic surveillance, DNA replication, and DNA repair. p12 degradation is dependent on the apical ataxia telangiectasia and Rad3 related (ATR) kinase and is mediated by the ubiquitin-proteasome system. Pol δ3 exhibits properties of an "antimutator" polymerase, suggesting that it could contribute to an increased surveillance against mutagenesis, for example, when Pol δ carries out bypass synthesis past small base lesions that engage in spurious base pairing. Chromatin immunoprecipitation analysis and examination of the spatiotemporal recruitment of Pol δ to sites of DNA damage show that Pol δ3 is the primary form of Pol δ associated with cyclobutane pyrimidine dimer lesions and therefore should be considered as the operative form of Pol δ engaged in DNA repair. We propose a model for the switching of Pol δ with translesion polymerases, incorporating the salient features of the recently determined structure of monoubiquitinated proliferating cell nuclear antigen and emphasizing the role of Pol δ3. Because of the critical role of Pol δ activity in DNA replication and repair, the formation of Pol δ3 in response to DNA damage opens the prospect that pleiotropic effects may ensue. This opens the horizons for future exploration of how this novel response to DNA damage contributes to genomic stability.
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Affiliation(s)
- Marietta Y W T Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
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Hu Z, Perumal SK, Yue H, Benkovic SJ. The human lagging strand DNA polymerase δ holoenzyme is distributive. J Biol Chem 2012; 287:38442-8. [PMID: 22942285 DOI: 10.1074/jbc.m112.404319] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polymerase δ is widely accepted as the lagging strand replicative DNA polymerase in eukaryotic cells. It forms a replication complex in the presence of replication factor C and proliferating cell nuclear antigen to perform efficient DNA synthesis in vivo. In this study, the human lagging strand holoenzyme was reconstituted in vitro. The rate of DNA synthesis of this holoenzyme, measured with a singly primed ssM13 DNA substrate, is 4.0 ± 0.4 nucleotides. Results from adenosine 5'-(3-thiotriphosphate) tetralithium salt (ATPγS) inhibition experiments revealed the nonprocessive characteristic of the human DNA polymerase (Pol δ) holoenzyme (150 bp for one binding event), consistent with data from chase experiments with catalytically inactive mutant Pol δ(AA). The ATPase activity of replication factor C was characterized and found to be stimulated ∼10-fold in the presence of both proliferating cell nuclear antigen and DNA, but the activity was not shut down by Pol δ in accord with rapid association/dissociation of the holoenzyme to/from DNA. It is noted that high concentrations of ATP inhibit the holoenzyme DNA synthesis activity, most likely due to its inhibition of the clamp loading process.
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Affiliation(s)
- Zhenxin Hu
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Wang JL, Guo HL, Wang PC, Liu CG. Age-dependent down-regulation of DNA polymerase δ1 in human lymphocytes. Mol Cell Biochem 2012; 371:157-63. [PMID: 22915169 DOI: 10.1007/s11010-012-1432-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Accepted: 08/03/2012] [Indexed: 01/19/2023]
Abstract
Aging progress and degeneracy of functional activity are mainly attributed to the decreased DNA repair potential. DNA polymerase (pol) δ activity plays an essential role in genome stability by virtue of its crucial DNA replication and repair capacity. To order to clarify the role of DNA pol δ in aging progression, we firstly examined the expressions of its catalytic subunit named DNA pol δ1 in human lymphocytes at different age stages, respectively, and then observed the effect of diseases on DNA pol δ1 in vivo and of nutriture on its expressions in 2BS cells in vitro. Blood samples from the healthy subjects and patients with diabetes mellitus and coronary heart disease were collected, respectively, for analysis of transcription and protein expressions of DNA pol δ1 by RT-PCR and western blot. 2BS cells of PD30 and PD47 were incubated in both normal medium and other mediums of different nutritures for verifying the differential expressions of DNA pol δ1. Results showed that the mRNA expression of DNA pol δ1 decreased substantially with age and the protein levels were well consistent with gene levels. Furthermore, there were no significant differences in DNA pol δ1 expressions between the groups of healthy individuals and the age matched patients. In addition, DNA pol δ1 gene expression levels were not affected by nutritional status in vitro. Our findings collectively confirmed that the down-regulations of DNA pol δ1 are age-related and have little bearing on diseases and nutritures. DNA pol δ1 has great potential for a new biomarker of aging.
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Affiliation(s)
- Jin-Ling Wang
- Department of Clinical Laboratory, Xuanwu Hospital, Capital Medical University, Beijing 100053, People's Republic of China
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39
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Zhou Y, Meng X, Zhang S, Lee EYC, Lee MYWT. Characterization of human DNA polymerase delta and its subassemblies reconstituted by expression in the MultiBac system. PLoS One 2012; 7:e39156. [PMID: 22723953 PMCID: PMC3377666 DOI: 10.1371/journal.pone.0039156] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 05/18/2012] [Indexed: 11/18/2022] Open
Abstract
Mammalian DNA polymerase δ (Pol δ), a four-subunit enzyme, plays a crucial and versatile role in DNA replication and DNA repair processes. We have reconstituted human Pol δ complexes in insect cells infected with a single baculovirus into which one or more subunits were assembled. This system allowed for the efficient expression of the tetrameric Pol δ holoenzyme, the p125/p50 core dimer, the core+p68 trimer and the core+p12 trimer, as well as the p125 catalytic subunit. These were isolated in milligram amounts with reproducible purity and specific activities by a highly standardized protocol. We have systematically compared their activities in order to gain insights into the roles of the p12 and p68 subunits, as well as their responses to PCNA. The relative specific activities (apparent k(cat)) of the Pol δ holoenzyme, core+p68, core+p12 and p125/p50 core were 100, 109, 40, and 29. The corresponding apparent K(d)'s for PCNA were 7.1, 8.7, 9.3 and 73 nM. Our results support the hypothesis that Pol δ interacts with PCNA through multiple interactions, and that there may be a redundancy in binding interactions that may permit Pol δ to adopt flexible configurations with PCNA. The abilities of the Pol δ complexes to fully extend singly primed M13 DNA were examined. All the subassemblies except the core+p68 were defective in their abilities to completely extend the primer, showing that the p68 subunit has an important function in synthesis of long stretches of DNA in this assay. The core+p68 trimer could be reconstituted by addition of p12.
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Affiliation(s)
- Yajing Zhou
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
| | - Xiao Meng
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Ernest Y. C. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Marietta Y. W. T. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
- * E-mail:
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40
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Abstract
DNA polymerase δ (Pol δ) is a member of the B-family DNA polymerases and is one of the major replicative DNA polymerases in eukaryotes. In addition to chromosomal DNA replication it is also involved in DNA repair and recombination. Pol δ is a multi-subunit complex comprised of a catalytic subunit and accessory subunits. The latter subunits play a critical role in the regulation of Pol δ functions. Recent progress in the structural characterization of Pol δ, together with a vast number of biochemical and functional studies, provides the basis for understanding the intriguing mechanisms of its regulation during DNA replication, repair and recombination. In this chapter we review the current state of the Pol δ structure-function relationship with an emphasis on the role of its accessory subunits.
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Affiliation(s)
- Tahir H Tahirov
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198-7696, USA,
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41
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Rahmeh AA, Zhou Y, Xie B, Li H, Lee EYC, Lee MYWT. Phosphorylation of the p68 Subunit of Pol δ Acts as a Molecular Switch To Regulate Its Interaction with PCNA. Biochemistry 2011; 51:416-24. [DOI: 10.1021/bi201638e] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Amal A. Rahmeh
- Department
of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, United States
| | - Yajing Zhou
- Department
of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, United States
| | - Bin Xie
- Department
of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, United States
| | - Hao Li
- Department
of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, United States
| | - Ernest Y. C. Lee
- Department
of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, United States
| | - Marietta Y. W. T. Lee
- Department
of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, United States
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42
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Wang Y, Zhang Q, Chen H, Li X, Mai W, Chen K, Zhang S, Lee EYC, Lee MYWT, Zhou Y. P50, the small subunit of DNA polymerase delta, is required for mediation of the interaction of polymerase delta subassemblies with PCNA. PLoS One 2011; 6:e27092. [PMID: 22073260 PMCID: PMC3206906 DOI: 10.1371/journal.pone.0027092] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 10/10/2011] [Indexed: 11/18/2022] Open
Abstract
Mammalian DNA polymerase δ (pol δ), a four-subunit enzyme, plays a crucial and versatile role in DNA replication and various DNA repair processes. Its function as a chromosomal DNA polymerase is dependent on the association with proliferating cell nuclear antigen (PCNA) which functions as a molecular sliding clamp. All four of the pol δ subunits (p125, p50, p68, and p12) have been reported to bind to PCNA. However, the identity of the subunit of pol δ that directly interacts with PCNA and is therefore primarily responsible for the processivity of the enzyme still remains controversial. Previous model for the network of protein-protein interactions of the pol δ-PCNA complex showed that pol δ might be able to interact with a single molecule of PCNA homotrimer through its three subunits, p125, p68, and p12 in which the p50 was not included in. Here, we have confirmed that the small subunit p50 of human pol δ truthfully interacts with PCNA by the use of far-Western analysis, quantitative ELISA assay, and subcellular co-localization. P50 is required for mediation of the interaction between pol δ subassemblies and PCNA homotrimer. Thus, pol δ interacts with PCNA via its four subunits.
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Affiliation(s)
- Yujue Wang
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
| | - Qian Zhang
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
| | - Huiqing Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
| | - Xiao Li
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
| | - Weijun Mai
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
| | - Keping Chen
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Ernest Y. C. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Marietta Y. W. T. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Yajing Zhou
- Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, People's Republic of China
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43
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Production of recombinant human DNA polymerase delta in a Bombyx mori bioreactor. PLoS One 2011; 6:e22224. [PMID: 21789240 PMCID: PMC3137619 DOI: 10.1371/journal.pone.0022224] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 06/21/2011] [Indexed: 11/30/2022] Open
Abstract
Eukaryotic DNA polymerase δ (pol δ) plays a crucial role in chromosomal DNA replication and various DNA repair processes. It is thought to consist of p125, p66 (p68), p50 and p12 subunits. However, rigorous isolation of mammalian pol δ from natural sources has usually yielded two-subunit preparations containing only p125 and p50 polypeptides. While recombinant pol δ isolated from infected insect cells have some problems of consistency in the quality of the preparations, and the yields are much lower. To address these deficiencies, we have constructed recombinant BmNPV baculoviruses using MultiBac system. This method makes the generation of recombinant forms of pol δ containing mutations in any one of the subunits or combinations thereof extremely facile. From about 350 infected larvae, we obtained as much as 4 mg of pol δ four-subunit complex. Highly purified enzyme behaved like the one of native form by rigorous characterization and comparison of its activities on poly(dA)/oligo(dT) template-primer and singly primed M13 DNA, and its homogeneity on FPLC gel filtration. In vitro base excision repair (BER) assays showed that pol δ plays a significant role in uracil-intiated BER and is more likely to mediate LP BER, while the trimer lacking p12 is more likely to mediate SN BER. It seems likely that loss of p12 modulates the rate of SN BER and LP BER during the repair process. Thus, this work provides a simple, fast, reliable and economic way for the large-scale production of human DNA polymerase δ with a high activity and purity, setting up a new platform for our further research on the biochemical properties of pol δ, its regulation and the integration of its functions, and how alterations in pol δ function could contribute to the etiology of human cancer or other diseases that can result from loss of genomic stability.
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Ruan XL, Li YJ, Wu Q, Liao LF, Xu H. P21 suppresses cell proliferation and down-regulates POLD1 expression in human gastric cancer cell line MGC-803. Shijie Huaren Xiaohua Zazhi 2011; 19:1990-1995. [DOI: 10.11569/wcjd.v19.i19.1990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate whether and how P21 regulates POLD1 expression in human gastric cancer cell line MGC-803 and to find new clues to blocking the malignant proliferation of cancer cells.
METHODS: MGC-803 cells were divided into three groups: blank control group (untransfected cells), negative control group (cells transfected with an empty vector pXJ41-neo), and experimental group (cells transfected with a eukaryotic expression plasmid pXJ41-p21). After transfection, cell proliferation was detected by MTT assay; cell apoptosis was detected by flow cytometry; and the mRNA and protein expression was detected by quantitative real-time PCR and Western blot, respectively.
RESULTS: Compared to the two control groups, cell proliferation was significantly inhibited, cell apoptosis was increased (11.36 ± 0.51 vs 7.39 ± 0.17, 7.69 ± 0.47, F = 85.338, P < 0.05), and the mRNA and protein expression of POLD1 was inhibited in the experimental group. In addition, the relative expression levels of cyclin E and Rb1 increased, that of CDK2 decreased, and that of c-myc showed little change in the experimental group when compared to the two control groups.
CONCLUSION: P21 can suppress cell proliferation and promote apoptosis in human gastric cancer cell line MGC-803. P21 can also suppress POLD1 expression possibly by regulating the expression of CDK2, cyclin E, Rb1 or other cell cycle factors in MGC-803 cells.
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45
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Brocas C, Charbonnier JB, Dhérin C, Gangloff S, Maloisel L. Stable interactions between DNA polymerase δ catalytic and structural subunits are essential for efficient DNA repair. DNA Repair (Amst) 2010; 9:1098-111. [PMID: 20813592 DOI: 10.1016/j.dnarep.2010.07.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 07/19/2010] [Accepted: 07/23/2010] [Indexed: 11/24/2022]
Abstract
Eukaryotic DNA polymerase δ (Pol δ) activity is crucial for chromosome replication and DNA repair and thus, plays an essential role in genome stability. In Saccharomyces cerevisiae, Pol δ is a heterotrimeric complex composed of the catalytic subunit Pol3, the structural B subunit Pol31, and Pol32, an additional auxiliary subunit. Pol3 interacts with Pol31 thanks to its C-terminal domain (CTD) and this interaction is of functional importance both in DNA replication and DNA repair. Interestingly, deletion of the last four C-terminal Pol3 residues, LSKW, in the pol3-ct mutant does not affect DNA replication but leads to defects in homologous recombination and in break-induced replication (BIR) repair pathways. The defect associated with pol3-ct could result from a defective interaction between Pol δ and a protein involved in recombination. However, we show that the LSKW motif is required for the interaction between Pol3 C-terminal end and Pol31. This loss of interaction is relevant in vivo since we found that pol3-ct confers HU sensitivity on its own and synthetic lethality with a POL32 deletion. Moreover, pol3-ct shows genetic interactions, both suppression and synthetic lethality, with POL31 mutant alleles. Structural analyses indicate that the B subunit of Pol δ displays a major conserved region at its surface and that pol31 alleles interacting with pol3-ct, correspond to substitutions of Pol31 amino acids that are situated in this particular region. Superimposition of our Pol31 model on the 3D architecture of the phylogenetically related DNA polymerase α (Pol α) suggests that Pol3 CTD interacts with the conserved region of Pol31, thus providing a molecular basis to understand the defects associated with pol3-ct. Taken together, our data highlight a stringent dependence on Pol δ complex stability in DNA repair.
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Affiliation(s)
- Clémentine Brocas
- CEA, DSV, iRCM, Bâtiment 05/BP6, Fontenay-aux-Roses, F-92265, France
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46
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Meng X, Zhou Y, Lee EYC, Lee MYWT, Frick DN. The p12 subunit of human polymerase delta modulates the rate and fidelity of DNA synthesis. Biochemistry 2010; 49:3545-54. [PMID: 20334433 PMCID: PMC2860660 DOI: 10.1021/bi100042b] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study examines the role of the p12 subunit in the function of the human DNA polymerase delta (Pol delta) holoenzyme by comparing the kinetics of DNA synthesis and degradation catalyzed by the four-subunit complex, the three-subunit complex lacking p12, and site-directed mutants of each lacking proofreading exonuclease activity. Results show that p12 modulates the rate and fidelity of DNA synthesis by Pol delta. All four complexes synthesize DNA in a rapid burst phase and a slower, more linear phase. In the presence of p12, the burst rates of DNA synthesis are approximately 5 times faster, while the affinity of the enzyme for its DNA and dNTP substrates appears unchanged. The p12 subunit alters Pol delta fidelity by modulating the proofreading 3' to 5' exonuclease activity. In the absence of p12, Pol delta is more likely to proofread DNA synthesis because it cleaves single-stranded DNA twice as fast and transfers mismatched DNA from the polymerase to the exonuclease sites 9 times faster. Pol delta also extends mismatched primers 3 times more slowly in the absence of p12. Taken together, the changes that p12 exerts on Pol delta are ones that can modulate its fidelity of DNA synthesis. The loss of p12, which occurs in cells upon exposure to DNA-damaging agents, converts Pol delta to a form that has an increased capacity for proofreading.
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Affiliation(s)
- Xiao Meng
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Yajing Zhou
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Ernest Y. C. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - Marietta Y. W. T. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
| | - David N. Frick
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595
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47
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Balakrishnan L, Gloor JW, Bambara RA. Reconstitution of eukaryotic lagging strand DNA replication. Methods 2010; 51:347-57. [PMID: 20178844 DOI: 10.1016/j.ymeth.2010.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Revised: 02/15/2010] [Accepted: 02/17/2010] [Indexed: 11/17/2022] Open
Abstract
Eukaryotic DNA replication is a complex process requiring the proper functioning of a multitude of proteins to create error-free daughter DNA strands and maintain genome integrity. Even though synthesis and joining of Okazaki fragments on the lagging strand involves only half the DNA in the nucleus, the complexity associated with processing these fragments is about twice that needed for leading strand synthesis. Flap endonuclease 1 (FEN1) is the central component of the Okazaki fragment maturation pathway. FEN1 cleaves flaps that are displaced by DNA polymerase delta (pol delta), to create a nick that is effectively joined by DNA ligase I. The Pif1 helicase and Dna2 helicase/nuclease contribute to the maturation process by elongating the flap displaced by pol delta. Though the reason for generating long flaps is still a matter of debate, genetic studies have shown that Dna2 and Pif1 are both important components of DNA replication. Our current knowledge of the exact enzymatic steps that govern Okazaki fragment maturation has heavily derived from reconstitution reactions in vitro, which have augmented genetic information, to yield current mechanistic models. In this review, we describe both the design of specific DNA substrates that simulate intermediates of fragment maturation and protocols for reconstituting partial and complete lagging strand replication.
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Affiliation(s)
- Lata Balakrishnan
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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48
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Huang QM, Akashi T, Masuda Y, Kamiya K, Takahashi T, Suzuki M. Roles of POLD4, smallest subunit of DNA polymerase delta, in nuclear structures and genomic stability of human cells. Biochem Biophys Res Commun 2009; 391:542-6. [PMID: 19931513 DOI: 10.1016/j.bbrc.2009.11.094] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 11/16/2009] [Indexed: 01/04/2023]
Abstract
Mammalian DNA polymerase delta (pol delta) is essential for DNA replication, though the functions of this smallest subunit of POLD4 have been elusive. We investigated pol delta activities in vitro and found that it was less active in the absence of POLD4, irrespective of the presence of the accessory protein PCNA. shRNA-mediated reduction of POLD4 resulted in a marked decrease in colony formation activity by Calu6, ACC-LC-319, and PC-10 cells. We also found that POLD4 reduction was associated with an increased population of karyomere-like cells, which may be an indication of DNA replication stress and/or DNA damage. The karyomere-like cells retained an ability to progress through the cell cycle, suggesting that POLD4 reduction induces modest genomic instability, while allowing cells to grow until DNA damage reaches an intolerant level. Our results indicate that POLD4 is required for the in vitro pol delta activity, and that it functions in cell proliferation and maintenance of genomic stability of human cells.
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Affiliation(s)
- Qin Miao Huang
- Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
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49
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Gao Y, Zhou Y, Xie B, Zhang S, Rahmeh A, Huang HS, Lee MYWT, Lee EYC. Protein Phosphatase-1 Is Targeted to DNA Polymerase δ via an Interaction with the p68 Subunit. Biochemistry 2008; 47:11367-76. [DOI: 10.1021/bi801122t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yan Gao
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Yajing Zhou
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Bin Xie
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Amal Rahmeh
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Hua-shan Huang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Marietta Y. W. T. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Ernest Y. C. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
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50
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Baranovskiy AG, Babayeva ND, Pavlov YI, Tahirov TH. Crystallization and preliminary crystallographic analysis of the complex of the second and third regulatory subunits of human Pol delta. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:822-4. [PMID: 18765914 DOI: 10.1107/s1744309108025086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 08/04/2008] [Indexed: 11/10/2022]
Abstract
Human DNA polymerase delta (Pol delta) consists of four subunits: p125, p50, p66 and p12. A heterodimer containing a His-tagged p50 subunit (p50) and a p50-interacting domain of the p66 subunit (p66(N)) was crystallized. The crystal was in the form of a prism with a rhombic cross-section and belonged to space group P2(1). The crystal had unit-cell parameters a = 95.13, b = 248.54, c = 103.46 A, beta = 106.94 degrees and diffracted to a resolution of 3 A. Four molecules of p50-p66(N) in an asymmetric unit corresponded to a crystal solvent content of 72.2%.
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Affiliation(s)
- Andrey G Baranovskiy
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-7696, USA
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