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Liu R, Li J, Shao J, Lee JH, Qiu X, Xiao Y, Zhang B, Hao Y, Li M, Chen Q. Innate immune response orchestrates phosphoribosyl pyrophosphate synthetases to support DNA repair. Cell Metab 2021; 33:2076-2089.e9. [PMID: 34343500 DOI: 10.1016/j.cmet.2021.07.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/09/2021] [Accepted: 06/12/2021] [Indexed: 02/08/2023]
Abstract
Ionizing radiation-induced DNA damages cause genome instability and are highly cytotoxic. Deoxyribonucleotide metabolism provides building blocks for DNA repair. Nevertheless, how deoxyribonucleotide metabolism is timely regulated to coordinate with DNA repair remains elusive. Here, we show that ionizing radiation results in TBK1-mediated phosphorylation of phosphoribosyl pyrophosphate synthetase (PRPS)1/2 at T228, thereby enhancing PRPS1/2 catalytic activity and promoting deoxyribonucleotide synthesis. DNA damage-elicited activation of cGAS/STING axis and ATM-mediated PRPS1/2 S16 phosphorylation are required for PRPS1/2 T228 phosphorylation under ionizing radiation. Furthermore, T228 phosphorylation overrides allosteric regulator-mediated effects and preserves PRPS1/2 with high activity. The expression of non-phosphorylatable PRPS1/2 mutants or inhibition of cGAS/STING axis counteracts ionizing radiation-induced PRPS1/2 activation, deoxyribonucleotide synthesis, and DNA repair, and further impairs cell viability. This study highlights a novel and important mechanism underlying an innate immune response-guided deoxyribonucleotide metabolism, which supports DNA repair.
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Affiliation(s)
- Rui Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China.
| | - Jingyi Li
- The Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, Chengdu, Sichuan 610051, China; School of Biological Sciences and Technology, Chengdu Medical College, Chengdu 610599, China
| | - Jichun Shao
- The Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, Chengdu, Sichuan 610051, China
| | - Jong-Ho Lee
- Department of Health Sciences, The Graduate School of Dong-A University, Busan 49315, Republic of Korea; Department of Biological Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Xuemei Qiu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Yanxuan Xiao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Bowen Zhang
- The Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, Chengdu, Sichuan 610051, China
| | - Yilong Hao
- Key Laboratory of Oral Biomedical Research of Zhejiang Province, and the Affiliated Hospital of Stomatology, School of Stomatology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Mi Li
- UTHealth Graduate School of Biomedical Sciences, Houston, TX 77225, USA
| | - Qianming Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China.
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Life in the serendipitous lane: excitement and gratification in studying DNA repair. DNA Repair (Amst) 2012; 11:595-605. [PMID: 22870513 DOI: 10.1016/j.dnarep.2011.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Interactions of replication versus repair DNA substrates with the Pol I DNA polymerases from Escherichia coli and Thermus aquaticus. Biophys Chem 2011; 159:188-93. [PMID: 21742429 DOI: 10.1016/j.bpc.2011.06.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 06/12/2011] [Accepted: 06/15/2011] [Indexed: 11/21/2022]
Abstract
Different DNA polymerases partition differently between replication and repair pathways. In this study we examine if two Pol I family polymerases from evolutionarily distant organisms also differ in their preferences for replication versus repair substrates. The DNA binding preferences of Klenow and Klentaq DNA polymerases, from Escherichia coli and Thermus aquaticus respectively, have been studied using a fluorescence competition binding assay. Klenow polymerase binds primed-template DNA (the replication substrate) with up to 50× higher affinity than it binds to nicked DNA, DNA with a 2 base single-stranded gap, blunt-ended DNA, or to a DNA end with a 3' overhang. In contrast, Klentaq binds all of these DNAs almost identically, indicating that Klenow has a stronger ability to discriminate between replication and repair substrates than Klentaq. In contrast, both polymerases bind mismatched primed-template and blunt-ended DNA tighter than they bind matched primed-template DNA, suggesting that these two proteins may share a similar mechanism to identify mismatched DNA, despite the fact that Klentaq has no proofreading ability. In addition, the presence or absence of 5'- or 3'-phosphates has slightly different effects on DNA binding by the two polymerases, but again reinforce Klenow's more effective substrate discrimination capability.
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Sobol RW. DNA polymerase beta null mouse embryonic fibroblasts harbor a homozygous null mutation in DNA polymerase iota. DNA Repair (Amst) 2006; 6:3-7. [PMID: 16979388 PMCID: PMC1868419 DOI: 10.1016/j.dnarep.2006.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Accepted: 08/16/2006] [Indexed: 02/06/2023]
Affiliation(s)
- Robert W. Sobol
- *To whom correspondence should be addressed: Robert W. Sobol, Hillman Cancer Center, University of Pittsburgh Cancer Institute, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863, Phone: 412-623-7764, Fax: 412-623-7761, e-mail:
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Sanderson RJ, Bennett SE, Sung JS, Mosbaugh DW. Uracil-initiated base excision DNA repair synthesis fidelity in human colon adenocarcinoma LoVo and Escherichia coli cell extracts. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2002; 68:165-88. [PMID: 11554295 DOI: 10.1016/s0079-6603(01)68098-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The error frequency of uracil-initiated base excision repair (BER) DNA synthesis in human and Escherichia coli cell-free extracts was determined by an M13mp2 lacZ alpha DNA-based reversion assay. Heteroduplex M13mp2 DNA was constructed that contained a site-specific uracil target located opposite the first nucleotide position of opal codon 14 in the lacZ alpha gene. Human glioblastoma U251 and colon adenocarcinoma LoVo whole-cell extracts repaired the uracil residue to produce form I DNA that was resistant to subsequent in vitro cleavage by E. coli uracil-DNA glycosylase (Ung) and endonuclease IV, indicating that complete uracil-initiated BER repair had occurred. Characterization of the BER reactions revealed that (1) the majority of uracil-DNA repair was initiated by a uracil-DNA glycosylase-sensitive to Ugi (uracil-DNA glycosylase inhibitor protein), (2) the addition of aphidicolin did not significantly inhibit BER DNA synthesis, and (3) the BER patch size ranged from 1 to 8 nucleotides. The misincorporation frequency of BER DNA synthesis at the target site was 5.2 x 10(-4) in U251 extracts and 5.4 x 10(-4) in LoVo extracts. The most frequent base substitution errors in the U251 and LoVo mutational spectrum were T to G > T to A >> T to C. Uracil-initiated BER DNA synthesis in extracts of E. coli BH156 (ung) BH157 (dug), and BH158 (ung, dug) was also examined. Efficient BER occurred in extracts of the BH157 strain with a misincorporation frequency of 5.6 x 10(-4). A reduced, but detectable level of BER was observed in extracts of E. coli BH156 cells; however, the mutation frequency of BER DNA synthesis was elevated 6.4-fold.
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Affiliation(s)
- R J Sanderson
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, USA
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6
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Bennett SE, Sung JS, Mosbaugh DW. Fidelity of uracil-initiated base excision DNA repair in DNA polymerase beta-proficient and -deficient mouse embryonic fibroblast cell extracts. J Biol Chem 2001; 276:42588-600. [PMID: 11551933 DOI: 10.1074/jbc.m106212200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Uracil-initiated base excision DNA repair was conducted using homozygous mouse embryonic fibroblast DNA polymerase beta (+/+) and (-/-) cells to determine the error frequency and mutational specificity associated with the completed repair process. Form I DNA substrates were constructed with site-specific uracil residues at U.A, U.G, and U.T targets contained within the lacZalpha gene of M13mp2 DNA. Efficient repair was observed in both DNA polymerase beta (+/+) and (-/-) cell-free extracts. Repair was largely dependent on uracil-DNA glycosylase activity because addition of the PBS-2 uracil-DNA glycosylase inhibitor (Ugi) protein reduced ( approximately 88%) the initial rate of repair in both types of cell-free extracts. In each case, the DNA repair patch size was primarily distributed between 1 and 8 nucleotides in length with 1 nucleotide repair patch constituting approximately 20% of the repair events. Addition of p21 peptide or protein to DNA polymerase beta (+/+) cell-free extracts increased the frequency of short-patch (1 nucleotide) repair by approximately 2-fold. The base substitution reversion frequency associated with uracil-DNA repair of M13mp2op14 (U.T) DNA was determined to be 5.7-7.2 x 10(-4) when using DNA polymerase beta (+/+) and (-/-) cell-free extracts. In these two cases, the error frequency was very similar, but the mutational spectrum was noticeably different. The presence or absence of Ugi did not dramatically influence either the error rate or mutational specificity. In contrast, the combination of Ugi and p21 protein promoted an increase in the mutation frequency associated with repair of M13mp2 (U.G) DNA. Examination of the mutational spectra generated by a forward mutation assay revealed that errors in DNA repair synthesis occurred predominantly at the position of the U.G target and frequently involved a 1-base deletion or incorporation of dTMP.
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Affiliation(s)
- S E Bennett
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331-7301, USA
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Fritz LK, Suquet C, Smerdon MJ. Strand breaks are repaired efficiently in human ribosomal genes. J Biol Chem 1996; 271:12972-6. [PMID: 8662972 DOI: 10.1074/jbc.271.22.12972] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We examined repair of DNA strand breaks induced by the anti-cancer drug bleomycin in both Pol I and Pol II transcribed genes in permeabilized human fibroblasts. The majority of these breaks (>80%) are single strand breaks (SSBs) thought to be repaired by base excision repair enzymes. Repair was examined in each strand of a 7. 2-kilobase fragment, completely within the Pol I transcribed region of ribosomal DNA (rDNA) and an 8.3-kilobase fragment completely within the Pol II transcribed region of the dihydrofolate reductase (DHFR) gene. Bleomycin dose-response studies revealed no bias for SSBs in either strand of the rDNA fragment. Furthermore, repair of SSBs is rapid (approximately 80% resealed in 60 min) in both the transcribed and nontranscribed strands of rDNA. Rapid repair of SSBs is also observed in both strands of the DHFR gene (approximately 60% resealed in 60 min). In contrast, little (or no) repair of UV photodimers occurs in either strand of human rDNA, regardless of whether cells are confluent or actively growing. Thus, DNA lesions in human ribosomal genes may be more accessible to base excision repair enzymes than those involved in nucleotide excision repair.
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Affiliation(s)
- L K Fritz
- Department of Biochemistry and Biophysics, Washington State University, Pullman, Washington 99164-4660, USA
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Prasad R, Beard W, Wilson S. Studies of gapped DNA substrate binding by mammalian DNA polymerase beta. Dependence on 5'-phosphate group. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32422-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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9
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Mosbaugh DW, Bennett SE. Uracil-excision DNA repair. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1994; 48:315-70. [PMID: 7938553 DOI: 10.1016/s0079-6603(08)60859-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- D W Mosbaugh
- Department of Agricultural Chemistry, Biochemistry and Biophysics, Oregon State University, Corvallis 97331
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Niranjanakumari S, Gopinathan KP. DNA polymerase-beta from the pupal ovaries of Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 1993; 23:345-353. [PMID: 8485527 DOI: 10.1016/0965-1748(93)90018-n] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The silk glands of Bombyx mori, a highly replicative tissue contains high levels of DNA polymerases alpha, delta and epsilon but not DNA polymerase-beta. However, we detected the latter activity in the gonadal tissues, viz. the pupal ovaries and testes of B. mori. The enzyme has been purified to homogeneity from the pupal ovaries by a series of column chromatographic and affinity purification steps. The enzyme satisfied the criteria to be designated as DNA polymerase-beta based on its small size, requirement for high concentration of monovalent cations for catalytic activity, sensitivity to ddTTP and insensitivity to aphidicolin. It is a monomeric polypeptide of M(r) 40 kDa, and the Km for dNTPs ranges between 8-20 microM. DNA polymerase-beta is biochemically and immunologically distinct from DNA polymerase-alpha from the silk glands of B. mori. The enzyme showed a preference for gapped DNA, and could not elongate ultraviolet irradiated template beyond the pyrimidine dimers. The absence of any associated primase and exonuclease activities from this enzyme, and its conspicuous absence in the highly replicative tissue, imply that it is unlikely to participate in the DNA endoreplication process.
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Affiliation(s)
- S Niranjanakumari
- Microbiology and Cell Biology Department, Indian Institute of Science, Bangalore
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11
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Park IS, Park JK, Koh HY, Park SD. DNA single stranded gaps formed during DNA repair synthesis induced by methyl methanesulfonate are filled by sequential action of aphidicolin- and dideoxythymidine sensitive DNA polymerases in HeLa cells. Cell Biol Toxicol 1991; 7:49-58. [PMID: 1905189 DOI: 10.1007/bf00121329] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
DNA repair synthesis induced by methyl methanesulfonate in preconditioned HeLa cells in which DNA replicative synthesis had been highly suppressed was inhibited by aphidicolin (an inhibitor of DNA polymerases alpha and delta) and dideoxythymidine (ddThR, an inhibitor of DNA polymerase beta). Incomplete repair patches sensitive to exonuclease III were accumulated in the presence of aphidicolin while not in the presence of ddThR. These patches were comopleted by the combined action of Klenow fragment and T4 DNA ligase, indicating that the single-stranded gaps were formed during the repair synthesis. Moreover, ddThR had little effect on the repair synthesis in the presence of aphidicolin. Thus, the results suggest that the single-stranded gaps may be sealed first by aphidicolin-sensitive polymerase followed by ddThR-sensitive DNA polymerase on the same site of the repair patch.
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Affiliation(s)
- I S Park
- Department of Zoology, College of Natural Sciences, Seoul National University, Republic of Korea
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12
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Davey SK, Faust EA. Murine DNA polymerase alpha fills gaps to completion in a direct assay. Altered kinetics of de novo DNA synthesis at single nucleotide gaps. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39707-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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13
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Park IS, Koh HY, Park JK, Park SD. Two different mechanisms are involved for the bleomycin-induced DNA repair synthesis in permeabilized HeLa cells. Biochem Biophys Res Commun 1989; 164:1226-33. [PMID: 2480115 DOI: 10.1016/0006-291x(89)91800-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Bleomycin-induced DNA repair synthesis in the permeabilized HeLa cells was sensitive to aphidicolin, an inhibitor of DNA polymerase alpha and delta, and to dideoxythymidine triphosphate (ddTTP), a specific inhibitor of DNA polymerase beta. Upon combined treatment with these inhibitors, the DNA repair synthesis was inhibited to an even higher degree. This indicated that the aphidicolin- and ddTTP-sensitive DNA repair syntheses may occur by independent mechanisms. The structure of incomplete repair patches being accumulated in the presence of these inhibitors was investigated by digestion of DNA with exonuclease III after incubation with Klenow fragment and T4 DNA ligase. The results have suggested that the patch accumulating in the presence of aphidicolin is a single-stranded gap made by excision enzyme(s), whereas that accumulating in the presence of ddTTP may be generated by strand displacement.
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Affiliation(s)
- I S Park
- Department of Zoology, College of Natural Sciences, Seoul National University, Republic of Korea
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14
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Jutras D, Marion M, Denizeau F. The effects of putative DNA repair inhibitors on DNA adduct levels and unscheduled DNA synthesis in rat hepatocytes exposed to 2-acetylaminofluorene. Mutat Res 1989; 216:35-42. [PMID: 2537461 DOI: 10.1016/0165-1161(89)90021-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The enzymology of DNA repair is currently under active investigation. The purpose of the present study was to examine the involvement of a number of enzymes (DNA polymerase alpha and beta, DNA topoisomerase II and ribonucleotide reductase) in the repair of chemically induced DNA damage in a mammalian cell system. This was done by studying the effects of inhibitors of these enzymes on the levels of 2-acetylaminofluorene (2-AAF)-DNA adducts and on the induction of UDS in primary cultures of rat hepatocytes exposed to the carcinogen in vitro. The results obtained with aphidicolin (an inhibitor of DNA polymerase alpha) show that the binding of 2-AAF to cellular DNA was significantly higher in samples exposed to this compound. Moreover, induction of UDS by 2-AAF was completely blocked in the presence of this compound. Dideoxythymidine, a DNA polymerase beta inhibitor, led to complex results. It produced a reduced DNA-specific activity due to [3H]2-AAF adduct formation as well as a diminished but still detectable UDS response in the presence of 2-AAF. Inhibitors of DNA topoisomerase II (nalidixic acid) and ribonucleotide reductase (hydroxyurea) did not cause any statistically significant change in the accumulation of 2-AAF adducts nor did they affect the induction of UDS. The data clearly suggest that DNA polymerase alpha participates in the repair of 2-AAF adducts in hepatocytes. In addition, neither DNA topoisomerase II activity, nor limitations in the precursor nucleotide pools appear to be critical factors in this process.
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Affiliation(s)
- D Jutras
- Department of Chemistry, Université du Québec à Montréal, Canada
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van Rensburg EJ, Louw WK, Engelbrecht RI, Izatt HL. Aphidicolin inhibition of gamma-radiation-induced DNA repair in human lymphocyte subpopulations. GENERAL PHARMACOLOGY 1989; 20:433-6. [PMID: 2502469 DOI: 10.1016/0306-3623(89)90192-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. DNA repair was measured in 3 Gy gamma-irradiated human peripheral lymphocyte subpopulations by means of nucleoid sedimentation. 2. The influence of aphidicolin (an inhibitor of DNA polymerase) on the repair process was investigated. 3. Repair of 40-44% of the DNA lesions induced by gamma-irradiation was blocked by aphidicolin. 4. Enriched B- and T-lymphocyte fractions were affected by aphidicolin to the same extent.
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Affiliation(s)
- E J van Rensburg
- AEC Institute for Life Sciences, University of Pretoria, South Africa
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Busbee D, Sylvia V, Curtin G, Peng S, Srivastava V, Tilley R. Age-related changes in DNA polymerase alpha expression. Exp Gerontol 1989; 24:395-413. [PMID: 2561101 DOI: 10.1016/0531-5565(89)90047-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
DNA polymerase alpha isozymes differing in specific activity and affinity of binding to DNA were purified from human fibroblasts derived from donors of different ages. Fetal-derived fibroblasts expressed a single, high-activity enzyme (A2), with high affinity of binding to DNA. Adult-derived fibroblasts exhibited two forms of DNA polymerase alpha, one identical to the fetal enzyme, and a second with about tenfold less activity showing low affinity of binding to DNA (A1). The ratio of DNA polymerase A2/A1 decreased dramatically with age, from 100% A2 in fetal-derived fibroblasts to about 94% A1 in fibroblasts derived from a 66-year-old donor. The DNA binding affinity of polymerase alpha A1 from adult-derived fibroblasts increased concomitant with a significant increase in activity when the enzyme was treated with phosphatidylinositol-4-monophosphate (PIP), or with inositol-1, 4-bisphosphate (I(1,4)P2). The enzyme reverted back to a less active form, with loss of the noncovalently bound I(1,4)P2, as a function of time. When permeabilized human fibroblasts with low DNA excision repair capacity were treated with 7,8-dihydrodiol-9,10-epoxybenzo(a)-pyrene (BPDE) in the presence of 32P-ATP, phosphatidylinositol, and cycloheximide, excision repair was initiated and 32P-labeled DNA polymerase alpha was recovered in the absence of de novo protein synthesis. DNA synthesis associated with either scheduled DNA synthesis or BPDE-initiated excision repair declined as a function of increased age in human cells. The data suggest that the decline in both DNA excision repair-associated and mitogen-activated DNA synthesis may be correlated with decreased total intracellular levels of DNA polymerase and with the decline in polymerase alpha activity as a function of age, that DNA repair-associated initiation of DNA synthesis in adult-derived cells may increase with activation of a pool of low activity DNA polymerase alpha, and that DNA polymerase alpha activity increases as a function of enzyme interaction with a component of the PI phosphorylation cascade.
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Affiliation(s)
- D Busbee
- Department of Anatomy, College of Veterinary Medicine, Texas A&M University, College Station 77843
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17
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Sylvia VL, Norman JO, Curtin GM, Stec J, Busbee DL. Purification of Norman Murine Sarcoma DNA polymerase alpha forms with different DNA template primer binding affinity and different specific activity. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1989; 21:203-8. [PMID: 2744201 DOI: 10.1016/0020-711x(89)90110-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
1. DNA polymerase alpha was isolated from Norman Murine Myxosarcoma cells using ion exchange, immunoaffinity, and DNA affinity chromatography, showing two distinct enzyme forms designated A1 and A2. 2. Chromatographic analysis of polymerase alpha forms A1 and A2 indicate a charge difference and a difference in affinity of binding to DNA between polymerase alpha forms which were equally reactive to anti-DNA polymerase alpha monoclonal IgG. 3. Polymerase A1 specific activity was about 3600 U/mg while A2 specific activity was about 40,000 U/mg.
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Affiliation(s)
- V L Sylvia
- Department of Anatomy, College of Veterinary Medicine, Texas A&M University, College Station 77843
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18
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Wang Z, Mosbaugh DW. Uracil-DNA Glycosylase Inhibitor Gene of Bacteriophage PBS2 Encodes a Binding Protein Specific for Uracil-DNA Glycosylase. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)85067-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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19
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Sylvia VL, Joe CO, Norman JO, Curtin GM, Tilley RD, Busbee DL. Interaction of phosphatidylinositol-4-monophosphate with a low activity form of DNA polymerase alpha: a potential mechanism for enzyme activation. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1989; 21:347-53. [PMID: 2545477 DOI: 10.1016/0020-711x(89)90357-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
1. DNA polymerase alpha isolated from Norman murine myxosarcoma exhibited two isozyme forms, one with low specific activity and low DNA binding affinity (A1), and one with high specific activity and high DNA binding affinity (A2). 2. DNA polymerase alpha A1, but not A2, showed a significant increase in specific activity after treatment with phosphatidylinositol, ATP and phosphatidylinositol kinase, or with phosphatidylinositol-4-monophosphate. 3. Treatment of DNA polymerase alpha A1 with the phospholipase C hydrolysis product of phosphatidylinositol-4-monophosphate, inositol-1,4-bisphosphate, was sufficient to effect the transient increase in activity of polymerase A1 to a form not chromatographically distinguishable from isozyme form A2.
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Affiliation(s)
- V L Sylvia
- Department of Anatomy, College of Veterinary Medicine, Texas A & M University, College Station 77843
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20
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Randahl H, Elliott GC, Linn S. DNA-repair reactions by purified HeLa DNA polymerases and exonucleases. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37744-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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21
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Baker JC, Ames BN. Alterations in levels of 5'-adenyl dinucleotides following DNA damage in normal human fibroblasts and fibroblasts derived from patients with xeroderma pigmentosum. Mutat Res 1988; 208:87-93. [PMID: 2454402 DOI: 10.1016/s0165-7992(98)90005-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Levels of 5'-adenyl dinucleotides, measured as diadenosine-5',5'''-P1,P4-tetraphosphate (Ap4A), were found to accumulate in cultured human fibroblasts following treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), the radiomimetic drug bleomycin, and nitroquinoline-1-oxide (NQO) or UV-irradiation in the presence of cytosine arabinofuranoside (araC). In contrast, cells derived from patients with xeroderma pigmentosum complementation group A (XP-A) did not demonstrate an increase in DNA-strand breaks following UV irradiation or NQO in the presence of araC nor an increase in Ap4A levels. Ap4A accumulation did occur in XP-A cells following treatment with MNNG. Cells derived from patients characterized as XP variants, which are incision repair-proficient, accumulated 5'-dinucleotides following bleomycin, MNNG and UV or NQO in the presence of araC. Taken together, these data suggest that Ap4A accumulates as a response to DNA-strand breaks.
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Affiliation(s)
- J C Baker
- Department of Biochemistry, University of California, Berkeley 94720
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Krauss S, Mochly-Rosen D, Koshland D, Linn S. Exposure of HeLa DNA polymerase alpha to protein kinase C affects its catalytic properties. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61368-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Abstract
In ciliates there are examples of cells which have different proliferation potential in the macronucleus. Those species with limited macronuclear proliferation potential require sex to activate the reserve nucleus. In terms of the capital investment theory, some ciliates invested in their spare nucleus without loss of their original potential, while others accumulated debts and needed the reserve account to maintain life. Other cells neglected maintenance of their reserve account and failed unless their venture capital account was not a self-sustaining venture. Sex provided access to the reserve account and had to occur before deterioration of the reserve account. The question is not when cellular immortality was lost, but rather when immortality was partitioned from a mortal segment. The separation provided the option both for senescence and evolution in multicellular organisms. In colonial flagellates, separation of cells with infinite and finite cell lifespan potential occurred in some species, while in others the separation did not involve loss of immortality. In colonial flagellates, sex did not become an obligate stage. The immortal cells are haploid and could not accumulate damage and live (in contrast with the diploids in the ciliated protozoans). The present theory predicts that differences between species or cells with infinite versus finite lifespan potential may reveal differences in the critical determinants of longevity. Senescence could arise as an accident, as well as a design of nuclear differentiation. Cells therefore may have a much greater reserve for totipotency than would be predicted if they were assumed to lose immortality simply by the act of differentiation.
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Affiliation(s)
- J Smith-Sonneborn
- Department of Zoology and Physiology, University of Wyoming, Laramie 82071
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Kozu T, Seno T, Yagura T. Activity levels of mouse DNA polymerase alpha-primase complex (DNA replicase) and DNA polymerase alpha, free from primase activity in synchronized cells, and a comparison of their catalytic properties. EUROPEAN JOURNAL OF BIOCHEMISTRY 1986; 157:251-9. [PMID: 3086093 DOI: 10.1111/j.1432-1033.1986.tb09663.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To asses the possible roles of the two active forms of mouse DNA polymerase alpha: primase--DNA-polymerase alpha complex (DNA replicase) and DNA polymerase alpha free from primase activity (7.3S polymerase), in nuclear DNA replication the correlation of their activity levels with the rate of nuclear DNA replication was determined and a comparison made of their catalytic properties. The experiments using either C3H2K cells, synchronized by serum starvation, or Ehrlich culture cells, arrested at the S phase by aphidicolin, showed DNA replicase to increase in cells in the S phase to at least six times that of the G0-phase cells but 7.3S polymerase to increase but slightly in this phase. This increase in DNA replicase activity most likely resulted from synthesis of a new enzyme, as shown by experiments using a specific monoclonal antibody, aphidicolin and cycloheximide. Not only with respect to the presence or absence of primase activity, but in other points as well the catalytic properties of these two forms were found to differ; DNA replicase preferred the activated calf thymus DNA with wide gaps of about 100 nucleotides long as a template-primer, while the optimal gap size for 7.3S polymerase was 40-50 nucleotides long. Size analysis of the products synthesized on M13 single-stranded circular DNA with a single 17-nucleotide primer by DNA replicase and 7.3S polymerase suggested the ability of DNA replicase to overcome a secondary structure formed in single-stranded DNA to be greater than that of 7.3S polymerase.
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Structural and enzymological characterization of immunoaffinity-purified DNA polymerase alpha.DNA primase complex from KB cells. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(19)57496-8] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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26
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Sono A, Sakaguchi K. The influence of a protein synthesis inhibitor on sister-chromatid exchange in the plant Vicia faba. Mutat Res 1986; 173:257-61. [PMID: 3081803 DOI: 10.1016/0165-7992(86)90020-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cycloheximide strongly antagonizes the induction of sister-chromatid exchange by mitomycin C in Vicia faba root tips. This behavior is analogous to that previously observed in mammalian cells (Sono and Sakaguchi, 1981) and suggests that newly synthesized protein is also required for recombination between sister DNA molecules in plants. Conversely hydroxyurea is shown to increase the frequency of both spontaneous and induced sister-chromatid exchange. Based on these results, possible mechanisms underlying sister-chromatid exchange formation in plants are discussed with special emphasis on the absence of DNA polymerase beta in somatic tissues.
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Sylvia VL, Joe CO, Norman JO, Curtin GM, Busbee DL. Phosphatidylinositol-dependent activation of DNA polymerase alpha. Biochem Biophys Res Commun 1986; 135:880-5. [PMID: 3964278 DOI: 10.1016/0006-291x(86)91010-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
DNA polymerase alpha was activated in vitro by cAMP-independent, phospholipid-dependent, protein kinase catalytic subunit. Of the phospholipids examined, phosphatidylinositol showed the greatest potential for interaction with protein kinase and ATP to activate DNA polymerase alpha in vitro. DNA polymerase alpha was directly activated by phosphorylated phosphatidylinositol in the absence of protein kinase and ATP. Activation of DNA polymerase alpha as a function of phosphorylation was demonstrated using 32P-ATP as the phosphate donor. In vitro treatment of the enzyme with phosphatidylinositol produced Linweaver-Burk plots showing noncompetitive kinetics of enzyme activation, suggesting that activation occurs prior to binding of the enzyme to DNA template/primer. These data indicate that DNA polymerase alpha may be activated in vitro in the presence of protein kinase, ATP, and phosphatidylinositol, and suggest that phosphorylation of the enzyme may constitute an intracellular mechanism of enzyme activation.
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Trosko JE, Chang CC. Role of intercellular communication in modifying the consequences of mutations in somatic cells. BASIC LIFE SCIENCES 1986; 39:439-56. [PMID: 3767847 DOI: 10.1007/978-1-4684-5182-5_39] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Loeb LA, Liu PK, Fry M. DNA polymerase-alpha: enzymology, function, fidelity, and mutagenesis. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1986; 33:57-110. [PMID: 3797680 DOI: 10.1016/s0079-6603(08)60020-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Krauss SW, Linn S. Studies of DNA polymerases alpha and beta from cultured human cells in various replicative states. J Cell Physiol 1986; 126:99-106. [PMID: 3944201 DOI: 10.1002/jcp.1041260114] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
DNA polymerase activities from HeLa cells and from cultured diploid human fibroblasts in various growth states were compared. alpha-Polymerase activities from log phase fibroblasts treated with sodium butyrate and from stationary phase HeLa cells had DEAE-cellulose elution patterns that differed from those of polymerases from dividing cells. Moreover, alpha- and beta-polymerases from nondividing cells replicated synthetic polymers less faithfully. Although similar changes were observed previously for polymerases from late-passage and postconfluent early passage fibroblasts, amounts of alpha-polymerase activity recovered from nondividing cells in this study did not dramatically decline as they had in the former cases. The alpha-polymerase activities from HeLa cells and fibroblasts in various growth states sedimented near 7.5S in 0.4 M KCI and could be inhibited by a monoclonal IgG fraction prepared against KB cell alpha-polymerase. By several criteria, there was no significant differences in levels of UV-stimulated repair synthesis observed in early or late-passage postconfluent fibroblasts or in log phase fibroblasts treated with sodium butyrate. In summary, levels of alpha-polymerase do not necessarily correlate either with replicative activity or with apparent levels of repair synthesis. However, cells with decreased replicative activity always yielded enzyme with decreased fidelity in vitro and altered chromatographic behavior. It appears, therefore, that the alterations observed for alpha-polymerase from late-passage cells may be attributed more generally to the nondividing nature of these cells.
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Abstract
A number of enzymes thought to be involved in DNA replication have been identified in the brain. These include single-stranded DNA-binding proteins, topoisomerases I and II, DNA polymerase alpha, a protein that binds Ap4A and might be classified as a DNA polymerase alpha accessory protein, RNase H, DNA polymerase beta, DNA ligase, an endo- and an exonuclease of unknown function, DNA methyl transferase and poly(ADPR) synthase. In contrast, little is known about the enzymology of DNA repair in brain. The few enzymes identified comprise uracil-DNA glycosylase, DNA polymerase beta, DNA polymerase alpha (which in neurons is present only at immature stages), DNA ligase, poly(ADPR) synthase, and O6-alkylguanine-DNA alkyltransferase. In addition, an exonuclease acting on depurinated single-stranded DNA (tentatively listed here as 3'----5' exonuclease), an endonuclease of unknown function as well as ill-defined acid and alkaline deoxyribonucleases also occur in brain.
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The mutational specificity of DNA polymerases-alpha and -gamma during in vitro DNA synthesis. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(17)38958-5] [Citation(s) in RCA: 114] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Effects of aphidicolin and/or 2‘,3‘-dideoxythymidine on DNA repair induced in HeLa cells by four types of DNA-damaging agents. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(19)85098-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Keyse SM, Tyrrell RM. Excision repair in permeable arrested human skin fibroblasts damaged by UV (254 nm) radiation: evidence that alpha- and beta-polymerases act sequentially at the repolymerisation step. Mutat Res 1985; 146:109-19. [PMID: 4000149 DOI: 10.1016/0167-8817(85)90061-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have characterised far-ultraviolet-radiation-induced DNA-repair synthesis in permeabilised arrested (non-dividing) primary human skin fibroblasts. Approximately half the maximum repair synthesis is seen after a UV fluence of 4.0 Jm-2 and little additional incorporation was observed at fluences above 20.0 Jm-2. UV-damaged permeable cells were treated with specific inhibitors of DNA polymerase alpha and beta, both alone and in combination. The degree of inhibition of repair incorporation by aphidicolin indicates that polymerase alpha is involved in the majority (85-90%) of repair synthesis after both high and low (less than 4.0 Jm-2) UV fluences. Dideoxythymidine triphosphate seems able to inhibit DNA-repair synthesis only when polymerase alpha is fully or almost fully functional, indicating that polymerase beta is unable to substitute in repair for an alpha polymerase blocked by aphidicolin. These data suggest that the two enzymes may act sequentially to complete repair patches rather than acting independently.
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