Journal articles: 'Polymerase alpha'

1

Gibbs, J. S., K. Weisshart, P. Digard, A. deBruynKops, D. M. Knipe, and D. M. Coen. "Polymerization activity of an alpha-like DNA polymerase requires a conserved 3'-5' exonuclease active site." Molecular and Cellular Biology 11, no. 9 (September 1991): 4786–95. http://dx.doi.org/10.1128/mcb.11.9.4786-4795.1991.

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Most DNA polymerases are multifunctional proteins that possess both polymerizing and exonucleolytic activities. For Escherichia coli DNA polymerase I and its relatives, polymerase and exonuclease activities reside on distinct, separable domains of the same polypeptide. The catalytic subunits of the alpha-like DNA polymerase family share regions of sequence homology with the 3'-5' exonuclease active site of DNA polymerase I; in certain alpha-like DNA polymerases, these regions of homology have been shown to be important for exonuclease activity. This finding has led to the hypothesis that alpha-like DNA polymerases also contain a distinct 3'-5' exonuclease domain. We have introduced conservative substitutions into a 3'-5' exonuclease active site homology in the gene encoding herpes simplex virus DNA polymerase, an alpha-like polymerase. Two mutants were severely impaired for viral DNA replication and polymerase activity. The mutants were not detectably affected in the ability of the polymerase to interact with its accessory protein, UL42, or to colocalize in infected cell nuclei with the major viral DNA-binding protein, ICP8, suggesting that the mutation did not exert global effects on protein folding. The results raise the possibility that there is a fundamental difference between alpha-like DNA polymerases and E. coli DNA polymerase I, with less distinction between 3'-5' exonuclease and polymerase functions in alpha-like DNA polymerases.

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2

Gibbs, J. S., K. Weisshart, P. Digard, A. deBruynKops, D. M. Knipe, and D. M. Coen. "Polymerization activity of an alpha-like DNA polymerase requires a conserved 3'-5' exonuclease active site." Molecular and Cellular Biology 11, no. 9 (September 1991): 4786–95. http://dx.doi.org/10.1128/mcb.11.9.4786.

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Most DNA polymerases are multifunctional proteins that possess both polymerizing and exonucleolytic activities. For Escherichia coli DNA polymerase I and its relatives, polymerase and exonuclease activities reside on distinct, separable domains of the same polypeptide. The catalytic subunits of the alpha-like DNA polymerase family share regions of sequence homology with the 3'-5' exonuclease active site of DNA polymerase I; in certain alpha-like DNA polymerases, these regions of homology have been shown to be important for exonuclease activity. This finding has led to the hypothesis that alpha-like DNA polymerases also contain a distinct 3'-5' exonuclease domain. We have introduced conservative substitutions into a 3'-5' exonuclease active site homology in the gene encoding herpes simplex virus DNA polymerase, an alpha-like polymerase. Two mutants were severely impaired for viral DNA replication and polymerase activity. The mutants were not detectably affected in the ability of the polymerase to interact with its accessory protein, UL42, or to colocalize in infected cell nuclei with the major viral DNA-binding protein, ICP8, suggesting that the mutation did not exert global effects on protein folding. The results raise the possibility that there is a fundamental difference between alpha-like DNA polymerases and E. coli DNA polymerase I, with less distinction between 3'-5' exonuclease and polymerase functions in alpha-like DNA polymerases.

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3

Herschbach, B. M., and A. D. Johnson. "The yeast alpha 2 protein can repress transcription by RNA polymerases I and II but not III." Molecular and Cellular Biology 13, no. 7 (July 1993): 4029–38. http://dx.doi.org/10.1128/mcb.13.7.4029-4038.1993.

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The alpha 2 protein of the yeast Saccharomyces cerevisiae normally represses a set of cell-type-specific genes (the a-specific genes) that are transcribed by RNA polymerase II. In this study, we determined whether alpha 2 can affect transcription by other RNA polymerases. We find that alpha 2 can repress transcription by RNA polymerase I but not by RNA polymerase III. Additional experiments indicate that alpha 2 represses RNA polymerase I transcription through the same pathway that it uses to repress RNA polymerase II transcription. These results implicate conserved components of the transcription machinery as mediators of alpha 2 repression and exclude several alternate models.

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4

Herschbach, B. M., and A. D. Johnson. "The yeast alpha 2 protein can repress transcription by RNA polymerases I and II but not III." Molecular and Cellular Biology 13, no. 7 (July 1993): 4029–38. http://dx.doi.org/10.1128/mcb.13.7.4029.

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The alpha 2 protein of the yeast Saccharomyces cerevisiae normally represses a set of cell-type-specific genes (the a-specific genes) that are transcribed by RNA polymerase II. In this study, we determined whether alpha 2 can affect transcription by other RNA polymerases. We find that alpha 2 can repress transcription by RNA polymerase I but not by RNA polymerase III. Additional experiments indicate that alpha 2 represses RNA polymerase I transcription through the same pathway that it uses to repress RNA polymerase II transcription. These results implicate conserved components of the transcription machinery as mediators of alpha 2 repression and exclude several alternate models.

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5

Moses, K., and C. Prives. "A unique subpopulation of murine DNA polymerase alpha/primase specifically interacts with polyomavirus T antigen and stimulates DNA replication." Molecular and Cellular Biology 14, no. 4 (April 1994): 2767–76. http://dx.doi.org/10.1128/mcb.14.4.2767-2776.1994.

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Murine cells or cell extracts support the replication of plasmids containing the replication origin (ori-DNA) of polyomavirus (Py) but not that of simian virus 40 (SV40), whereas human cells or cell extracts support the replication of SV40 ori-DNA but not that of Py ori-DNA. It was shown previously that fractions containing DNA polymerase alpha/primase from permissive cells allow viral ori-DNA replication to proceed in extracts of nonpermissive cells. To extend these observations, the binding of Py T antigen to both the permissive and nonpermissive DNA polymerase alpha/primase was examined. Py T antigen was retained by a murine DNA polymerase alpha/primase but not by a human DNA polymerase alpha/primase affinity column. Likewise, a Py T antigen affinity column retained DNA polymerase alpha/primase activity from murine cells but not from human cells. The murine fraction which bound to the Py T antigen column was able to stimulate Py ori-DNA replication in the nonpermissive extract. However, the DNA polymerase alpha/primase activity in this murine fraction constituted only a relatively small proportion (approximately 20 to 40%) of the total murine DNA polymerase alpha/primase that had been applied to the column. The DNA polymerase alpha/primase purified from the nonbound murine fraction, although far more replete in this activity, was incapable of supporting Py DNA replication. The two forms of murine DNA polymerase alpha/primase also differed in their interactions with Py T antigen. Our data thus demonstrate that there are two distinct populations of DNA polymerase alpha/primase in murine cells and that species-specific interactions between T antigen and DNA polymerases can be identified. They may also provide the basis for initiating a novel means of characterizing unique subpopulations of DNA polymerase alpha/primase.

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6

Moses, K., and C. Prives. "A unique subpopulation of murine DNA polymerase alpha/primase specifically interacts with polyomavirus T antigen and stimulates DNA replication." Molecular and Cellular Biology 14, no. 4 (April 1994): 2767–76. http://dx.doi.org/10.1128/mcb.14.4.2767.

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Murine cells or cell extracts support the replication of plasmids containing the replication origin (ori-DNA) of polyomavirus (Py) but not that of simian virus 40 (SV40), whereas human cells or cell extracts support the replication of SV40 ori-DNA but not that of Py ori-DNA. It was shown previously that fractions containing DNA polymerase alpha/primase from permissive cells allow viral ori-DNA replication to proceed in extracts of nonpermissive cells. To extend these observations, the binding of Py T antigen to both the permissive and nonpermissive DNA polymerase alpha/primase was examined. Py T antigen was retained by a murine DNA polymerase alpha/primase but not by a human DNA polymerase alpha/primase affinity column. Likewise, a Py T antigen affinity column retained DNA polymerase alpha/primase activity from murine cells but not from human cells. The murine fraction which bound to the Py T antigen column was able to stimulate Py ori-DNA replication in the nonpermissive extract. However, the DNA polymerase alpha/primase activity in this murine fraction constituted only a relatively small proportion (approximately 20 to 40%) of the total murine DNA polymerase alpha/primase that had been applied to the column. The DNA polymerase alpha/primase purified from the nonbound murine fraction, although far more replete in this activity, was incapable of supporting Py DNA replication. The two forms of murine DNA polymerase alpha/primase also differed in their interactions with Py T antigen. Our data thus demonstrate that there are two distinct populations of DNA polymerase alpha/primase in murine cells and that species-specific interactions between T antigen and DNA polymerases can be identified. They may also provide the basis for initiating a novel means of characterizing unique subpopulations of DNA polymerase alpha/primase.

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7

Zuber, M., E. M. Tan, and M. Ryoji. "Involvement of proliferating cell nuclear antigen (cyclin) in DNA replication in living cells." Molecular and Cellular Biology 9, no. 1 (January 1989): 57–66. http://dx.doi.org/10.1128/mcb.9.1.57-66.1989.

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Proliferating cell nuclear antigen (PCNA) (also called cyclin) is known to stimulate the activity of DNA polymerase delta but not the other DNA polymerases in vitro. We injected a human autoimmune antibody against PCNA into unfertilized eggs of Xenopus laevis and examined the effects of this antibody on the replication of injected plasmid DNA as well as egg chromosomes. The anti-PCNA antibody inhibited plasmid replication by up to 67%, demonstrating that PCNA is involved in plasmid replication in living cells. This result further implies that DNA polymerase delta is necessary for plasmid replication in vivo. Anti-PCNA antibody alone did not block plasmid replication completely, but the residual replication was abolished by coinjection of a monoclonal antibody against DNA polymerase alpha. Anti-DNA polymerase alpha alone inhibited plasmid replication by 63%. Thus, DNA polymerase alpha is also required for plasmid replication in this system. In similar studies on the replication of egg chromosomes, the inhibition by anti-PCNA antibody was only 30%, while anti-DNA polymerase alpha antibody blocked 73% of replication. We concluded that the replication machineries of chromosomes and plasmid differ in their relative content of DNA polymerase delta. In addition, we obtained evidence through the use of phenylbutyl deoxyguanosine, an inhibitor of DNA polymerase alpha, that the structure of DNA polymerase alpha holoenzyme for chromosome replication is significantly different from that for plasmid replication.

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8

Zuber, M., E. M. Tan, and M. Ryoji. "Involvement of proliferating cell nuclear antigen (cyclin) in DNA replication in living cells." Molecular and Cellular Biology 9, no. 1 (January 1989): 57–66. http://dx.doi.org/10.1128/mcb.9.1.57.

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Proliferating cell nuclear antigen (PCNA) (also called cyclin) is known to stimulate the activity of DNA polymerase delta but not the other DNA polymerases in vitro. We injected a human autoimmune antibody against PCNA into unfertilized eggs of Xenopus laevis and examined the effects of this antibody on the replication of injected plasmid DNA as well as egg chromosomes. The anti-PCNA antibody inhibited plasmid replication by up to 67%, demonstrating that PCNA is involved in plasmid replication in living cells. This result further implies that DNA polymerase delta is necessary for plasmid replication in vivo. Anti-PCNA antibody alone did not block plasmid replication completely, but the residual replication was abolished by coinjection of a monoclonal antibody against DNA polymerase alpha. Anti-DNA polymerase alpha alone inhibited plasmid replication by 63%. Thus, DNA polymerase alpha is also required for plasmid replication in this system. In similar studies on the replication of egg chromosomes, the inhibition by anti-PCNA antibody was only 30%, while anti-DNA polymerase alpha antibody blocked 73% of replication. We concluded that the replication machineries of chromosomes and plasmid differ in their relative content of DNA polymerase delta. In addition, we obtained evidence through the use of phenylbutyl deoxyguanosine, an inhibitor of DNA polymerase alpha, that the structure of DNA polymerase alpha holoenzyme for chromosome replication is significantly different from that for plasmid replication.

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9

Rowe-Magnus, Dean A., Mario Mencía, Fernando Rojo, Margarita Salas, and George B. Spiegelman. "Transcriptional Activation of the Bacillus subtilis spoIIG Promoter by the Response Regulator Spo0A Is Independent of the C-Terminal Domain of the RNA Polymerase Alpha Subunit." Journal of Bacteriology 180, no. 17 (September 1, 1998): 4760–63. http://dx.doi.org/10.1128/jb.180.17.4760-4763.1998.

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ABSTRACT In vitro transcription from the spoIIG promoter byBacillus subtilis RNA polymerase reconstituted with wild-type alpha subunits and with C-terminal deletion mutants of the alpha subunit was equally stimulated by the response regulator Spo0A. Some differences in the structure of open complexes formed by RNA polymerase containing alpha subunit mutants were noted, although the wild-type and mutant polymerases appeared to use the same initiation mechanism.

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10

Hałas, A., A. Ciesielski, and J. Zuk. "Involvement of the essential yeast DNA polymerases in induced gene conversion." Acta Biochimica Polonica 46, no. 4 (December 31, 1999): 862–72. http://dx.doi.org/10.18388/abp.1999_4107.

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In the yeast Saccharomyces cerevisiae three different DNA polymerases alpha, delta and epsilon are involved in DNA replication. DNA polymerase alpha is responsible for initiation of DNA synthesis and polymerases delta and epsilon are required for elongation of DNA strand during replication. DNA polymerases delta and epsilon are also involved in DNA repair. In this work we studied the role of these three DNA polymerases in the process of recombinational synthesis. Using thermo-sensitive heteroallelic mutants in genes encoding DNA polymerases we studied their role in the process of induced gene conversion. Mutant strains were treated with mutagens, incubated under permissive or restrictive conditions and the numbers of convertants obtained were compared. A very high difference in the number of convertants between restrictive and permissive conditions was observed for polymerases alpha and delta, which suggests that these two polymerases play an important role in DNA synthesis during mitotic gene conversion. Marginal dependence of gene conversion on the activity of polymerase epsilon indicates that this DNA polymerase may be involved in this process but rather as an auxiliary enzyme.

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11

Sui, Yang, Lei Qi, Ke Zhang, Natalie Saini, Leszek J. Klimczak, Cynthia J. Sakofsky, Dmitry A. Gordenin, Thomas D. Petes, and Dao-Qiong Zheng. "Analysis of APOBEC-induced mutations in yeast strains with low levels of replicative DNA polymerases." Proceedings of the National Academy of Sciences 117, no. 17 (April 10, 2020): 9440–50. http://dx.doi.org/10.1073/pnas.1922472117.

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Yeast strains with low levels of the replicative DNA polymerases (alpha, delta, and epsilon) have high levels of chromosome deletions, duplications, and translocations. By examining the patterns of mutations induced in strains with low levels of DNA polymerase by the human protein APOBEC3B (a protein that deaminates cytosine in single-stranded DNA), we show dramatically elevated amounts of single-stranded DNA relative to a wild-type strain. During DNA replication, one strand (defined as the leading strand) is replicated processively by DNA polymerase epsilon and the other (the lagging strand) is replicated as short fragments initiated by DNA polymerase alpha and extended by DNA polymerase delta. In the low DNA polymerase alpha and delta strains, the APOBEC-induced mutations are concentrated on the lagging-strand template, whereas in the low DNA polymerase epsilon strain, mutations occur on the leading- and lagging-strand templates with similar frequencies. In addition, for most genes, the transcribed strand is mutagenized more frequently than the nontranscribed strand. Lastly, some of the APOBEC-induced clusters in strains with low levels of DNA polymerase alpha or delta are greater than 10 kb in length.

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12

Budd, M. E., and J. L. Campbell. "DNA polymerases delta and epsilon are required for chromosomal replication in Saccharomyces cerevisiae." Molecular and Cellular Biology 13, no. 1 (January 1993): 496–505. http://dx.doi.org/10.1128/mcb.13.1.496-505.1993.

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Three DNA polymerases, alpha, delta, and epsilon are required for viability in Saccharomyces cerevisiae. We have investigated whether DNA polymerases epsilon and delta are required for DNA replication. Two temperature-sensitive mutations in the POL2 gene, encoding DNA polymerase epsilon, have been identified by using the plasmid shuffle technique. Alkaline sucrose gradient analysis of DNA synthesis products in the mutant strains shows that no chromosomal-size DNA is formed after shift of an asynchronous culture to the nonpermissive temperature. The only DNA synthesis observed is a reduced quantity of short DNA fragments. The DNA profiles of replication intermediates from these mutants are similar to those observed with DNA synthesized in mutants deficient in DNA polymerase alpha under the same conditions. The finding that DNA replication stops upon shift to the nonpermissive temperature in both DNA polymerase alpha- and DNA polymerase epsilon- deficient strains shows that both DNA polymerases are involved in elongation. By contrast, previous studies on pol3 mutants, deficient in DNA polymerase delta, suggested that there was considerable residual DNA synthesis at the nonpermissive temperature. We have reinvestigated the nature of DNA synthesis in pol3 mutants. We find that pol3 strains are defective in the synthesis of chromosomal-size DNA at the restrictive temperature after release from a hydroxyurea block. These results demonstrate that yeast DNA polymerase delta is also required at the replication fork.

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13

Budd, M. E., and J. L. Campbell. "DNA polymerases delta and epsilon are required for chromosomal replication in Saccharomyces cerevisiae." Molecular and Cellular Biology 13, no. 1 (January 1993): 496–505. http://dx.doi.org/10.1128/mcb.13.1.496.

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Three DNA polymerases, alpha, delta, and epsilon are required for viability in Saccharomyces cerevisiae. We have investigated whether DNA polymerases epsilon and delta are required for DNA replication. Two temperature-sensitive mutations in the POL2 gene, encoding DNA polymerase epsilon, have been identified by using the plasmid shuffle technique. Alkaline sucrose gradient analysis of DNA synthesis products in the mutant strains shows that no chromosomal-size DNA is formed after shift of an asynchronous culture to the nonpermissive temperature. The only DNA synthesis observed is a reduced quantity of short DNA fragments. The DNA profiles of replication intermediates from these mutants are similar to those observed with DNA synthesized in mutants deficient in DNA polymerase alpha under the same conditions. The finding that DNA replication stops upon shift to the nonpermissive temperature in both DNA polymerase alpha- and DNA polymerase epsilon- deficient strains shows that both DNA polymerases are involved in elongation. By contrast, previous studies on pol3 mutants, deficient in DNA polymerase delta, suggested that there was considerable residual DNA synthesis at the nonpermissive temperature. We have reinvestigated the nature of DNA synthesis in pol3 mutants. We find that pol3 strains are defective in the synthesis of chromosomal-size DNA at the restrictive temperature after release from a hydroxyurea block. These results demonstrate that yeast DNA polymerase delta is also required at the replication fork.

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14

Budd, M. E., and J. L. Campbell. "DNA polymerases required for repair of UV-induced damage in Saccharomyces cerevisiae." Molecular and Cellular Biology 15, no. 4 (April 1995): 2173–79. http://dx.doi.org/10.1128/mcb.15.4.2173.

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The ability of yeast DNA polymerase mutant strains to carry out repair synthesis after UV irradiation was studied by analysis of postirradiation molecular weight changes in cellular DNA. Neither DNA polymerase alpha, delta, epsilon, nor Rev3 single mutants evidenced a defect in repair. A mutant defective in all four of these DNA polymerases, however, showed accumulation of single-strand breaks, indicating defective repair. Pairwise combination of polymerase mutations revealed a repair defect only in DNA polymerase delta and epsilon double mutants. The extent of repair in the double mutant was no greater than that in the quadruple mutant, suggesting that DNA polymerases alpha and Rev3p play very minor, if any, roles. Taken together, the data suggest that DNA polymerases delta and epsilon are both potentially able to perform repair synthesis and that in the absence of one, the other can efficiently substitute. Thus, two of the DNA polymerases involved in DNA replication are also involved in DNA repair, adding to the accumulating evidence that the two processes are coupled.

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15

Schneider, C., K. Weisshart, L. A. Guarino, I. Dornreiter, and E. Fanning. "Species-specific functional interactions of DNA polymerase alpha-primase with simian virus 40 (SV40) T antigen require SV40 origin DNA." Molecular and Cellular Biology 14, no. 5 (May 1994): 3176–85. http://dx.doi.org/10.1128/mcb.14.5.3176-3185.1994.

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Physical and functional interactions of simian virus 40 (SV40) and polyomavirus large-T antigens with DNA polymerase alpha-primase were analyzed to elucidate the molecular basis for the species specificity of polymerase alpha-primase in viral DNA replication. SV40 T antigen associated more efficiently with polymerase alpha-primase in crude human extracts than in mouse extracts, while polyomavirus T antigen interacted preferentially with polymerase alpha-primase in mouse extracts. The apparent species specificity of complex formation was not observed when purified polymerase alpha-primases were substituted for the crude extracts. Several functional interactions between T antigen and purified polymerase alpha-primase, including stimulation of primer synthesis and primer elongation on M13 DNA in the presence or absence of the single-stranded DNA binding protein RP-A, also proved to be independent of the species from which polymerase alpha-primase had been purified. However, the human DNA polymerase alpha-primase was specifically required for primosome assembly and primer synthesis on SV40 origin DNA in the presence of T antigen and RP-A.

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16

Schneider, C., K. Weisshart, L. A. Guarino, I. Dornreiter, and E. Fanning. "Species-specific functional interactions of DNA polymerase alpha-primase with simian virus 40 (SV40) T antigen require SV40 origin DNA." Molecular and Cellular Biology 14, no. 5 (May 1994): 3176–85. http://dx.doi.org/10.1128/mcb.14.5.3176.

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Physical and functional interactions of simian virus 40 (SV40) and polyomavirus large-T antigens with DNA polymerase alpha-primase were analyzed to elucidate the molecular basis for the species specificity of polymerase alpha-primase in viral DNA replication. SV40 T antigen associated more efficiently with polymerase alpha-primase in crude human extracts than in mouse extracts, while polyomavirus T antigen interacted preferentially with polymerase alpha-primase in mouse extracts. The apparent species specificity of complex formation was not observed when purified polymerase alpha-primases were substituted for the crude extracts. Several functional interactions between T antigen and purified polymerase alpha-primase, including stimulation of primer synthesis and primer elongation on M13 DNA in the presence or absence of the single-stranded DNA binding protein RP-A, also proved to be independent of the species from which polymerase alpha-primase had been purified. However, the human DNA polymerase alpha-primase was specifically required for primosome assembly and primer synthesis on SV40 origin DNA in the presence of T antigen and RP-A.

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17

Gutierrez, C., Z. S. Guo, J. Farrell-Towt, G. Ju, and M. L. DePamphilis. "c-myc protein and DNA replication: separation of c-myc antibodies from an inhibitor of DNA synthesis." Molecular and Cellular Biology 7, no. 12 (December 1987): 4594–98. http://dx.doi.org/10.1128/mcb.7.12.4594-4598.1987.

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Antibodies against human c-myc protein have been reported to inhibit DNA polymerase activity and endogenous DNA synthesis in isolated nuclei, suggesting a role for c-myc in DNA replication. Using the same antibody preparations, we observed equivalent inhibition of simian virus 40 DNA replication and DNA polymerase alpha and delta activities in vitro, as well as inhibition of DNA synthesis in isolated nuclei. However, the c-myc antibodies could be completely separated from the DNA synthesis inhibition activity. c-myc antibodies prepared in other laboratories also did not interfere with initiation of simian virus 40 DNA replication, DNA synthesis at replication forks, or DNA polymerase alpha or delta activity. Therefore, the previously reported inhibition of DNA synthesis by some antibody preparations resulted from the presence of an unidentified inhibitor of DNA polymerases alpha and delta and not from the action of c-myc antibodies.

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18

Gutierrez, C., Z. S. Guo, J. Farrell-Towt, G. Ju, and M. L. DePamphilis. "c-myc protein and DNA replication: separation of c-myc antibodies from an inhibitor of DNA synthesis." Molecular and Cellular Biology 7, no. 12 (December 1987): 4594–98. http://dx.doi.org/10.1128/mcb.7.12.4594.

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Antibodies against human c-myc protein have been reported to inhibit DNA polymerase activity and endogenous DNA synthesis in isolated nuclei, suggesting a role for c-myc in DNA replication. Using the same antibody preparations, we observed equivalent inhibition of simian virus 40 DNA replication and DNA polymerase alpha and delta activities in vitro, as well as inhibition of DNA synthesis in isolated nuclei. However, the c-myc antibodies could be completely separated from the DNA synthesis inhibition activity. c-myc antibodies prepared in other laboratories also did not interfere with initiation of simian virus 40 DNA replication, DNA synthesis at replication forks, or DNA polymerase alpha or delta activity. Therefore, the previously reported inhibition of DNA synthesis by some antibody preparations resulted from the presence of an unidentified inhibitor of DNA polymerases alpha and delta and not from the action of c-myc antibodies.

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19

Enomoto, Takemi, Masashi Suzuki, Mikiko Takahashi, Katsumif Kawasaki, Yoshinari Watanabe, Kyosuke Nagata, Fumio Hanaoka, and Masa-atsu Yamada. "Purification and characterization of two forms of DNA polymerase .ALPHA. from mouse FM3A cells: A DNA polymerase .ALPHA.-primase complex and a free DNA polymerase .ALPHA.." Cell Structure and Function 10, no. 2 (1985): 161–71. http://dx.doi.org/10.1247/csf.10.161.

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20

Brückner, A., F. Stadlbauer, L. A. Guarino, A. Brunahl, C. Schneider, C. Rehfuess, C. Previes, E. Fanning, and H. P. Nasheuer. "The mouse DNA polymerase alpha-primase subunit p48 mediates species-specific replication of polyomavirus DNA in vitro." Molecular and Cellular Biology 15, no. 3 (March 1995): 1716–24. http://dx.doi.org/10.1128/mcb.15.3.1716.

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Mouse cell extracts support vigorous replication of polyomavirus (Py) DNA in vitro, while human cell extracts do not. However, the addition of purified mouse DNA polymerase alpha-primase to human cell extracts renders them permissive for Py DNA replication, suggesting that mouse polymerase alpha-primase determines the species specificity of Py DNA replication. We set out to identify the subunit of mouse polymerase alpha-primase that mediates this species specificity. To this end, we cloned and expressed cDNAs encoding all four subunits of mouse and human polymerase alpha-primase. Purified recombinant mouse polymerase alpha-primase and a hybrid DNA polymerase alpha-primase complex composed of human subunits p180 and p68 and mouse subunits p58 and p48 supported Py DNA replication in human cell extracts depleted of polymerase alpha-primase, suggesting that the primase heterodimer or one of its subunits controls host specificity. To determine whether both mouse primase subunits were required, recombinant hybrid polymerase alpha-primases containing only one mouse primase subunit, p48 or p58, together with three human subunits, were assayed for Py replication activity. Only the hybrid containing mouse p48 efficiently replicated Py DNA in depleted human cell extracts. Moreover, in a purified initiation assay containing Py T antigen, replication protein A (RP-A) and topoisomerase I, only the hybrid polymerase alpha-primase containing the mouse p48 subunit initiated primer synthesis on Py origin DNA. Together, these results indicate that the p48 subunit is primarily responsible for the species specificity of Py DNA replication in vitro. Specific physical association of Py T antigen with purified recombinant DNA polymerase alpha-primase, mouse DNA primase heterodimer, and mouse p48 suggested that direct interactions between Py T antigen and primase could play a role in species-specific initiation of Py replication.

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21

POPANDA, Odilia, and Heinz Walter THIELMANN. "DNA polymerase alpha from normal rat liver is different than DNA polymerases alpha from Morris hepatoma strains." European Journal of Biochemistry 183, no. 1 (July 1989): 5–13. http://dx.doi.org/10.1111/j.1432-1033.1989.tb14888.x.

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22

Simbulan, C. M., M. Suzuki, S. Izuta, T. Sakurai, E. Savoysky, K. Kojima, K. Miyahara, Y. Shizuta, and S. Yoshida. "Poly(ADP-ribose) polymerase stimulates DNA polymerase alpha by physical association." Journal of Biological Chemistry 268, no. 1 (January 1993): 93–99. http://dx.doi.org/10.1016/s0021-9258(18)54119-3.

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23

Hunting, Darel J., Bonnie J. Gowans, and Steven L. Dresler. "DNA polymerase delta mediates excision repair in growing cells damaged with ultraviolet radiation." Biochemistry and Cell Biology 69, no. 4 (April 1, 1991): 303–8. http://dx.doi.org/10.1139/o91-046.

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In confluent, stationary phase cells, an aphidicolin-sensitive DNA polymerase mediates UV-induced excision repair, but the situation in growing cells is still controversial. The sensitivity of repair synthesis to aphidicolin, an inhibitor of DNA polymerases alpha and delta, was determined in growth phase and confluent normal human fibroblasts (AG1518) using several techniques. Repair synthesis in confluent cells was always inhibited by aphidicolin, no matter which measurement technique was used. However, the inhibition of repair synthesis in growth-phase cells by aphidicolin was only detectable when techniques unaffected by changes in nucleotide metabolism were used. We conclude that UV-induced repair synthesis in growing cells is actually aphidicolin sensitive, but that this inhibition can be obscured by changes in nucleotide metabolism. Employing butylphenyl-deoxyguanosine triphosphate, a potent inhibitor of polymerase alpha and a weak inhibitor of delta, we have obtained evidence that polymerase delta is responsible for repair synthesis in growth-phase cells following UV irradiation.Key words: DNA polymerase, excision repair, ultraviolet radiation.

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24

Stokke, T., B. Erikstein, H. Holte, S. Funderud, and H. B. Steen. "Cell cycle-specific expression and nuclear binding of DNA polymerase alpha." Molecular and Cellular Biology 11, no. 6 (June 1991): 3384–89. http://dx.doi.org/10.1128/mcb.11.6.3384-3389.1991.

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The expression and distribution of DNA polymerase alpha was measured by cytometry and confocal laser scanning microscopy. Expression was proportional to DNA content in proliferating cells, while only S-phase cells retained DNA polymerase alpha after detergent extraction. Nuclear DNA polymerase alpha binding may be one of the key events of S-phase entry.

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25

Stokke, T., B. Erikstein, H. Holte, S. Funderud, and H. B. Steen. "Cell cycle-specific expression and nuclear binding of DNA polymerase alpha." Molecular and Cellular Biology 11, no. 6 (June 1991): 3384–89. http://dx.doi.org/10.1128/mcb.11.6.3384.

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The expression and distribution of DNA polymerase alpha was measured by cytometry and confocal laser scanning microscopy. Expression was proportional to DNA content in proliferating cells, while only S-phase cells retained DNA polymerase alpha after detergent extraction. Nuclear DNA polymerase alpha binding may be one of the key events of S-phase entry.

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26

Russo, F. D., and T. J. Silhavy. "Alpha: the Cinderella subunit of RNA polymerase." Journal of Biological Chemistry 267, no. 21 (July 1992): 14515–18. http://dx.doi.org/10.1016/s0021-9258(18)42065-0.

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27

Sylvia, V. L., C. O. Joe, J. O. Norman, G. M. Curtin, and D. L. Busbee. "Phosphatidylinositol-dependent activation of DNA polymerase alpha." Biochemical and Biophysical Research Communications 135, no. 3 (March 1986): 880–85. http://dx.doi.org/10.1016/0006-291x(86)91010-7.

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Wang, Z., X. Wu, and E. C. Friedberg. "DNA repair synthesis during base excision repair in vitro is catalyzed by DNA polymerase epsilon and is influenced by DNA polymerases alpha and delta in Saccharomyces cerevisiae." Molecular and Cellular Biology 13, no. 2 (February 1993): 1051–58. http://dx.doi.org/10.1128/mcb.13.2.1051-1058.1993.

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Base excision repair is an important mechanism for correcting DNA damage produced by many physical and chemical agents. We have examined the effects of the REV3 gene and the DNA polymerase genes POL1, POL2, and POL3 of Saccharomyces cerevisiae on DNA repair synthesis is nuclear extracts. Deletional inactivation of REV3 did not affect repair synthesis in the base excision repair pathway. Repair synthesis in nuclear extracts of pol1, pol2, and pol3 temperature-sensitive mutants was normal at permissive temperatures. However, repair synthesis in pol2 nuclear extracts was defective at the restrictive temperature of 37 degrees C and could be complemented by the addition of purified yeast DNA polymerase epsilon. Repair synthesis in pol1 nuclear extracts was proficient at the restrictive temperature unless DNA polymerase alpha was inactivated prior to the initiation of DNA repair. Thermal inactivation of DNA polymerase delta in pol3 nuclear extracts enhanced DNA repair synthesis approximately 2-fold, an effect which could be specifically reversed by the addition of purified yeast DNA polymerase delta to the extract. These results demonstrate that DNA repair synthesis in the yeast base excision repair pathway is catalyzed by DNA polymerase epsilon but is apparently modulated by the presence of DNA polymerases alpha and delta.

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Wang, Z., X. Wu, and E. C. Friedberg. "DNA repair synthesis during base excision repair in vitro is catalyzed by DNA polymerase epsilon and is influenced by DNA polymerases alpha and delta in Saccharomyces cerevisiae." Molecular and Cellular Biology 13, no. 2 (February 1993): 1051–58. http://dx.doi.org/10.1128/mcb.13.2.1051.

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Base excision repair is an important mechanism for correcting DNA damage produced by many physical and chemical agents. We have examined the effects of the REV3 gene and the DNA polymerase genes POL1, POL2, and POL3 of Saccharomyces cerevisiae on DNA repair synthesis is nuclear extracts. Deletional inactivation of REV3 did not affect repair synthesis in the base excision repair pathway. Repair synthesis in nuclear extracts of pol1, pol2, and pol3 temperature-sensitive mutants was normal at permissive temperatures. However, repair synthesis in pol2 nuclear extracts was defective at the restrictive temperature of 37 degrees C and could be complemented by the addition of purified yeast DNA polymerase epsilon. Repair synthesis in pol1 nuclear extracts was proficient at the restrictive temperature unless DNA polymerase alpha was inactivated prior to the initiation of DNA repair. Thermal inactivation of DNA polymerase delta in pol3 nuclear extracts enhanced DNA repair synthesis approximately 2-fold, an effect which could be specifically reversed by the addition of purified yeast DNA polymerase delta to the extract. These results demonstrate that DNA repair synthesis in the yeast base excision repair pathway is catalyzed by DNA polymerase epsilon but is apparently modulated by the presence of DNA polymerases alpha and delta.

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Dornreiter, I., W. C. Copeland, and T. S. Wang. "Initiation of simian virus 40 DNA replication requires the interaction of a specific domain of human DNA polymerase alpha with large T antigen." Molecular and Cellular Biology 13, no. 2 (February 1993): 809–20. http://dx.doi.org/10.1128/mcb.13.2.809-820.1993.

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Initiation of cell-free simian virus 40 (SV40) DNA replication requires the interaction of DNA polymerase alpha/primase with a preinitiation complex containing the viral T antigen and cellular proteins, replication protein A, and topoisomerase I or II. To further understand the molecular mechanisms of the transition from preinitiation to initiation, the intermolecular interaction between human DNA polymerase alpha and T antigen was investigated. We have demonstrated that the human DNA polymerase alpha catalytic polypeptide is able to associate with SV40 large T antigen directly under physiological conditions. A physical association between these two proteins was detected by coimmunoprecipitation with monoclonal antibodies from insect cells coinfected with recombinant baculoviruses. A domain of human polymerase alpha physically interacting with T antigen was identified within the amino-terminal region from residues 195 to 313. This domain of human polymerase alpha was able to form a nonproductive complex with T antigen, causing inhibition of the SV40 DNA replication in vitro. Kinetics of the inhibition indicated that this polymerase domain can inhibit viral replication only during the preinitiation stage. Extra molecules of T antigen could partially overcome the inhibition only prior to initiation complex formation. The data support the conclusion that initiation of SV40 DNA replication requires the physical interaction of T antigen in the preinitiation complex with the amino-terminal domain of human polymerase alpha from amino acid residues 195 to 313.

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Dornreiter, I., W. C. Copeland, and T. S. Wang. "Initiation of simian virus 40 DNA replication requires the interaction of a specific domain of human DNA polymerase alpha with large T antigen." Molecular and Cellular Biology 13, no. 2 (February 1993): 809–20. http://dx.doi.org/10.1128/mcb.13.2.809.

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Initiation of cell-free simian virus 40 (SV40) DNA replication requires the interaction of DNA polymerase alpha/primase with a preinitiation complex containing the viral T antigen and cellular proteins, replication protein A, and topoisomerase I or II. To further understand the molecular mechanisms of the transition from preinitiation to initiation, the intermolecular interaction between human DNA polymerase alpha and T antigen was investigated. We have demonstrated that the human DNA polymerase alpha catalytic polypeptide is able to associate with SV40 large T antigen directly under physiological conditions. A physical association between these two proteins was detected by coimmunoprecipitation with monoclonal antibodies from insect cells coinfected with recombinant baculoviruses. A domain of human polymerase alpha physically interacting with T antigen was identified within the amino-terminal region from residues 195 to 313. This domain of human polymerase alpha was able to form a nonproductive complex with T antigen, causing inhibition of the SV40 DNA replication in vitro. Kinetics of the inhibition indicated that this polymerase domain can inhibit viral replication only during the preinitiation stage. Extra molecules of T antigen could partially overcome the inhibition only prior to initiation complex formation. The data support the conclusion that initiation of SV40 DNA replication requires the physical interaction of T antigen in the preinitiation complex with the amino-terminal domain of human polymerase alpha from amino acid residues 195 to 313.

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32

Chen, H., C. B. Lawrence, S. K. Bryan, and R. E. Moses. "Aphidicolin inhibits DNA polymerase II ofEscherichia coli, an alpha-like DNA polymerase." Nucleic Acids Research 18, no. 23 (1990): 7185. http://dx.doi.org/10.1093/nar/18.23.7185.

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Collins, K. L., and T. J. Kelly. "Effects of T antigen and replication protein A on the initiation of DNA synthesis by DNA polymerase alpha-primase." Molecular and Cellular Biology 11, no. 4 (April 1991): 2108–15. http://dx.doi.org/10.1128/mcb.11.4.2108-2115.1991.

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Studies of simian virus 40 (SV40) DNA replication in a reconstituted cell-free system have established that T antigen and two cellular replication proteins, replication protein A (RP-A) and DNA polymerase alpha-primase complex, are necessary and sufficient for initiation of DNA synthesis on duplex templates containing the SV40 origin of DNA replication. To better understand the mechanism of initiation of DNA synthesis, we analyzed the functional interactions of T antigen, RP-A, and DNA polymerase alpha-primase on model single-stranded DNA templates. Purified DNA polymerase alpha-primase was capable of initiating DNA synthesis de novo on unprimed single-stranded DNA templates. This reaction involved the synthesis of a short oligoribonucleotide primer which was then extended into a DNA chain. We observed that the synthesis of ribonucleotide primers by DNA polymerase alpha-primase is dramatically stimulated by SV40 T antigen. The presence of T antigen also increased the average length of the DNA product synthesized on primed and unprimed single-stranded DNA templates. These stimulatory effects of T antigen required direct contact with DNA polymerase alpha-primase complex and were most marked at low template and polymerase concentrations. We also observed that the single-stranded DNA binding protein, RP-A, strongly inhibits the primase activity of DNA polymerase alpha-primase, probably by blocking access of the enzyme to the template. T antigen partially reversed the inhibition caused by RP-A. Our data support a model in which DNA priming is mediated by a complex between T antigen and DNA polymerase alpha-primase with the template, while RP-A acts to suppress nonspecific priming events.

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34

Collins, K. L., and T. J. Kelly. "Effects of T antigen and replication protein A on the initiation of DNA synthesis by DNA polymerase alpha-primase." Molecular and Cellular Biology 11, no. 4 (April 1991): 2108–15. http://dx.doi.org/10.1128/mcb.11.4.2108.

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Studies of simian virus 40 (SV40) DNA replication in a reconstituted cell-free system have established that T antigen and two cellular replication proteins, replication protein A (RP-A) and DNA polymerase alpha-primase complex, are necessary and sufficient for initiation of DNA synthesis on duplex templates containing the SV40 origin of DNA replication. To better understand the mechanism of initiation of DNA synthesis, we analyzed the functional interactions of T antigen, RP-A, and DNA polymerase alpha-primase on model single-stranded DNA templates. Purified DNA polymerase alpha-primase was capable of initiating DNA synthesis de novo on unprimed single-stranded DNA templates. This reaction involved the synthesis of a short oligoribonucleotide primer which was then extended into a DNA chain. We observed that the synthesis of ribonucleotide primers by DNA polymerase alpha-primase is dramatically stimulated by SV40 T antigen. The presence of T antigen also increased the average length of the DNA product synthesized on primed and unprimed single-stranded DNA templates. These stimulatory effects of T antigen required direct contact with DNA polymerase alpha-primase complex and were most marked at low template and polymerase concentrations. We also observed that the single-stranded DNA binding protein, RP-A, strongly inhibits the primase activity of DNA polymerase alpha-primase, probably by blocking access of the enzyme to the template. T antigen partially reversed the inhibition caused by RP-A. Our data support a model in which DNA priming is mediated by a complex between T antigen and DNA polymerase alpha-primase with the template, while RP-A acts to suppress nonspecific priming events.

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Fijalkowska, I. J., and R. M. Schaaper. "Antimutator mutations in the alpha subunit of Escherichia coli DNA polymerase III: identification of the responsible mutations and alignment with other DNA polymerases." Genetics 134, no. 4 (August 1, 1993): 1039–44. http://dx.doi.org/10.1093/genetics/134.4.1039.

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Abstract The dnaE gene of Escherichia coli encodes the DNA polymerase (alpha subunit) of the main replicative enzyme, DNA polymerase III holoenzyme. We have previously identified this gene as the site of a series of seven antimutator mutations that specifically decrease the level of DNA replication errors. Here we report the nucleotide sequence changes in each of the different antimutator dnaE alleles. For each a single, but different, amino acid substitution was found among the 1,160 amino acids of the protein. The observed substitutions are generally nonconservative. All affected residues are located in the central one-third of the protein. Some insight into the function of the regions of polymerase III containing the affected residues was obtained by amino acid alignment with other DNA polymerases. We followed the principles developed in 1990 by M. Delarue et al. who have identified in DNA polymerases from a large number of prokaryotic and eukaryotic sources three highly conserved sequence motifs, which are suggested to contain components of the polymerase active site. We succeeded in finding these three conserved motifs in polymerase III as well. However, none of the amino acid substitutions responsible for the antimutator phenotype occurred at these sites. This and other observations suggest that the effect of these mutations may be exerted indirectly through effects on polymerase conformation and/or DNA/polymerase interactions.

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Stadlbauer, F., C. Voitenleitner, A. Brückner, E. Fanning, and H. P. Nasheuer. "Species-specific replication of simian virus 40 DNA in vitro requires the p180 subunit of human DNA polymerase alpha-primase." Molecular and Cellular Biology 16, no. 1 (January 1996): 94–104. http://dx.doi.org/10.1128/mcb.16.1.94.

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Human cell extracts efficiently support replication of simian virus 40 (SV40) DNA in vitro, while mouse cell extracts do not. Since human DNA polymerase alpha-primase is the major species-specific factor, we set out to determine the subunit(s) of DNA polymerase alpha-primase required for this species specificity. Recombinant human, mouse, and hybrid human-mouse DNA polymerase alpha-primase complexes were expressed with baculovirus vectors and purified. All of the recombinant DNA polymerase alpha-primases showed enzymatic activity and efficiently synthesized the complementary strand on an M13 single-stranded DNA template. The human DNA polymerase alpha-primase (four subunits [HHHH]) and the hybrid DNA polymerase alpha-primase HHMM (two human subunits and two mouse subunits), containing human p180 and p68 and mouse primase, initiated SV40 DNA replication in a purified system. The human and the HHMM complex efficiently replicated SV40 DNA in mouse extracts from which DNA polymerase alpha-primase was deleted, while MMMM and the MMHH complex did not. To determine whether the human p180 or p68 subunit was required for SV40 DNA replication, hybrid complexes containing only one human subunit, p180 or p68, together with three mouse subunits (HMMM and MHMM) or three human subunits and one mouse subunit (MHHH and HMHH) were tested for SV40 DNA replication activity. The hybrid complexes HMMM and HMHH synthesized oligoribonucleotides in the SV40 initiation assay with purified proteins and replicated SV40 DNA in depleted mouse extracts. In contrast, the hybrid complexes containing mouse p180 were inactive in both assays. We conclude that the human p180 subunit determines host-specific replication of SV40 DNA in vitro.

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37

Niranjanakumari, S., and K. P. Gopinathan. "DNA polymerase α-primase complex from the silk glands of the non-mulberry silkworm Philosamia ricini." Biochemical Journal 298, no. 3 (March 15, 1994): 529–35. http://dx.doi.org/10.1042/bj2980529.

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The DNA content in the silk glands of the non-mulberry silkworm Philosamia ricini increases continuously during the fourth and fifth instars of larval development indicating high levels of DNA replication in this terminally differentiated tissue. Concomitantly, the DNA polymerase alpha activity also increases in the middle and the posterior silk glands during development, reaching maximal levels in the middle of the fifth larval instar. A comparable level of DNA polymerase delta/epsilon was also observed in this highly replicative tissue. The DNA polymerase alpha-primase complex from the silk glands of P. ricini has been purified to homogeneity by conventional column chromatography as well as by immunoaffinity techniques. The molecular mass of the native enzyme is 560 kDa and the enzyme comprises six non-identical subunits. The identity of the enzyme as DNA polymerase alpha has been established by its sensitivity to inhibitors such as aphidicolin, N-ethylmaleimide, butylphenyl-dGTP, butylanilino-dATP and antibodies to polymerase alpha. The enzyme possesses primase activity capable of initiating DNA synthesis on single-stranded DNA templates. The tight association of polymerase and primase activities at a constant ratio of 6:1 is observed through all the purification steps. The 180 kDa subunit harbours the polymerase activity, while the primase activity is associated with the 45 kDa subunit.

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38

Hockman, D. J., and M. C. Schultz. "Casein kinase II is required for efficient transcription by RNA polymerase III." Molecular and Cellular Biology 16, no. 3 (March 1996): 892–98. http://dx.doi.org/10.1128/mcb.16.3.892.

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Casein kinase II (CKII) is a ubiquitous and highly conserved serine/threonine protein kinase found in the nucleus and cytoplasm of most cells. Using a combined biochemical and genetic approach in the yeast Saccharomyces cerevisiae, we assessed the role of CKII in specific transcription by RNA polymerases I, II, and III. CKII is not required for basal transcription by RNA polymerases I and II but is important for polymerase III transcription. Polymerase III transcription is high in extracts with normal CKII activity but low in extracts from a temperature-sensitive mutant that has decreased CKII activity due to a lesion in the enzyme's catalytic alpha' subunit. Polymerase III transcription of 5S rRNA and tRNA templates in the temperature-sensitive extract is rescued by purified, wild-type CKII. An inhibitor of CKII represses polymerase III transcription in wild-type extract, and this repression is partly overcome by supplementing reaction mixtures with active CKII. Finally, we show that polymerase III transcription in vivo is impaired when CKII is inactivated. Our results demonstrate that CKII, an oncogenic protein kinase previously implicated in cell cycle and growth control, is required for high-level transcription by RNA polymerase III.

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39

Bialek, G., and F. Grosse. "An error-correcting proofreading exonuclease-polymerase that copurifies with DNA-polymerase-alpha-primase." Journal of Biological Chemistry 268, no. 8 (March 1993): 6024–33. http://dx.doi.org/10.1016/s0021-9258(18)53421-9.

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Park, H., S. Francesconi, and T. S. Wang. "Cell cycle expression of two replicative DNA polymerases alpha and delta from Schizosaccharomyces pombe." Molecular Biology of the Cell 4, no. 2 (February 1993): 145–57. http://dx.doi.org/10.1091/mbc.4.2.145.

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We have investigated the expression of two Schizosaccharomyces pombe replicative DNA polymerases alpha and delta during the cell cycle. The pol alpha+ and pol delta+ genes encoding DNA polymerases alpha and delta were isolated from S. pombe. Both pol alpha+ and pol delta+ genes are single copy genes in haploid cells and are essential for cell viability. In contrast to Saccharomyces cerevisiae homologs, the steady-state transcripts of both S. pombe pol alpha+ and pol delta+ genes were present throughout the cell cycle. Sequence analysis of the pol alpha+ and pol delta+ genes did not reveal the Mlu I motifs in their upstream sequences that are involved in cell cycle-dependent transcription of S. cerevisiae DNA synthesis genes as well as the S. pombe cdc22+ gene at the G1/S boundary. However, five near-match Mlu I motifs were found in the upstream region of the pol alpha+ gene. S. pombe DNA polymerases alpha and delta proteins were also expressed constantly throughout the cell cycle. In addition, the enzymatic activity of the S. pombe DNA polymerase alpha measured by in vitro assay was detected at all stages of the cell cycle. Thus, these S. pombe replicative DNA polymerases, like that of S. pombe cdc17+ gene, are expressed throughout the cell cycle at the transcriptional and protein level. These results indicate that S. pombe has at least two regulatory modes for the expression of genes involved in DNA replication and DNA precursor synthesis.

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Taricani, Lorena, Frances Shanahan, and David Parry. "Replication stress activates DNA polymerase alpha-associated Chk1." Cell Cycle 8, no. 3 (February 2009): 482–89. http://dx.doi.org/10.4161/cc.8.3.7661.

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42

Sheaff, Robert, Diane Ilsley, and Robert Kuchta. "Mechanism of DNA polymerase .alpha. inhibition by aphidicolin." Biochemistry 30, no. 35 (September 3, 1991): 8590–97. http://dx.doi.org/10.1021/bi00099a014.

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43

Nasheuer, Heinz Peter, and Frank Grosse. "Immunoaffinity-purified DNA polymerase .alpha. displays novel properties." Biochemistry 26, no. 25 (December 1987): 8458–66. http://dx.doi.org/10.1021/bi00399a064.

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44

Stec, Jan, and David Busbee. "DNA polymerase alpha activity in mitogen-activated lymphocytes." Biochemical and Biophysical Research Communications 153, no. 3 (June 1988): 1324–32. http://dx.doi.org/10.1016/s0006-291x(88)81373-1.

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45

Arabshahi, Lili, Neal Brown, Naseema Khan, and George Wright. "Inhibition of DNA polymerase alpha by aphidicolin derivatives." Nucleic Acids Research 16, no. 11 (1988): 5107–13. http://dx.doi.org/10.1093/nar/16.11.5107.

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46

NAKAYAMA, Masachi, and Masamichi KOHIYAMA. "An alpha-like DNA polymerase from Halobacterium halobium." European Journal of Biochemistry 152, no. 2 (October 1985): 293–97. http://dx.doi.org/10.1111/j.1432-1033.1985.tb09197.x.

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Floy, Kimberly M., Russell O. Hess, and Lorraine F. Meisner. "DNA polymerase alpha defect in the N syndrome." American Journal of Medical Genetics 35, no. 3 (March 1990): 301–5. http://dx.doi.org/10.1002/ajmg.1320350302.

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Miller, Michael R., Charles Seighman, and Roger G. Ulrich. "Inhibition of DNA replication and DNA polymerase .alpha. activity by monoclonal anti-(DNA polymerase .alpha.) IgG and F(ab) fragments." Biochemistry 24, no. 25 (December 1985): 7440–45. http://dx.doi.org/10.1021/bi00346a061.

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Job, C., D. Shire, V. Sure, and D. Job. "A DNA-dependent RNA synthesis by wheat-germ RNA polymerase II insensitive to the fungal toxin α-amanitin." Biochemical Journal 285, no. 1 (July 1, 1992): 85–90. http://dx.doi.org/10.1042/bj2850085.

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Wheat-germ RNA polymerase II is able to catalyse a DNA-dependent reaction of RNA synthesis in the presence of a high concentration (1 mg/ml) of the fungal toxin alpha-amanitin. This anomalous reaction is specifically directed by single-stranded or double-stranded homopolymer templates, such as poly(dC) or poly(dC).poly(dG), and occurs in the presence of either Mn2+ or Mg2+ as the bivalent metal cofactor. In contrast, the transcription of other synthetic templates, such as poly(dT), poly(dA).poly(dT) or poly[d(A-T)] is completely abolished in the presence of 1 microgram of alpha-amanitin/ml, in agreement with well-established biochemical properties of class II RNA polymerases. Size analysis of reaction products resulting from transcription of (dC)n templates of defined lengths suggests that polymerization of RNA chains proceeds through a slippage mechanism. The fact that alpha-amanitin does not impede this synthetic reaction implies that the amatoxin interferes with the translocation of wheat-germ RNA polymerase II along the DNA template.

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Takeoka, M., W. F. Ward, H. Pollack, D. W. Kamp, and R. J. Panos. "KGF facilitates repair of radiation-induced DNA damage in alveolar epithelial cells." American Journal of Physiology-Lung Cellular and Molecular Physiology 272, no. 6 (June 1, 1997): L1174—L1180. http://dx.doi.org/10.1152/ajplung.1997.272.6.l1174.

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Administration of exogenous keratinocyte growth factor (KGF) prevents or attenuates several forms of oxidant-mediated lung injury. Because DNA damage in epithelial cells is a component of radiation pneumotoxicity, we determined whether KGF ameliorated DNA strand breaks in irradiated A549 cells. Cells were exposed to 137Cs gamma rays, and DNA damage was measured by alkaline unwinding and ethidium bromide fluorescence after a 30-min recovery period. Radiation induced a dose-dependent increase in DNA strand breaks. The percentage of double-stranded DNA after exposure to 30 Gy increased from 44.6 +/- 3.5% in untreated control cells to 61.6 +/- 5.0% in cells cultured with 100 ng/ml KGF for 24 h (P < 0.05). No reduction in DNA damage occurred when the cells were cultured with KGF but maintained at 0 degree C during and after irradiation. The sparing effect of KGF on radiation-induced DNA damage was blocked by aphidicolin, an inhibitor of DNA polymerases-alpha, -delta, and -epsilon and by butylphenyl dGTP, which blocks DNA polymerase-alpha strongly and polymerases-delta and -epsilon less effectively. However, dideoxythymidine triphosphate, a specific inhibitor of DNA polymerase-beta, did not abrogate the KGF effect. Thus KGF increases DNA repair capacity in irradiated pulmonary epithelial cells, an effect mediated at least in part by DNA polymerases-alpha, -delta, and -epsilon. Enhancement of DNA repair capability after cell damage may be one mechanism by which KGF is able to ameliorate oxidant-mediated alveolar epithelial injury.

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Journal articles on the topic 'Polymerase alpha'

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