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DNA Synthesis by The Isolated Nuclear Matrix and Its Regulatory Mechanism

Research Project

Project/Area Number 03833012
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field 分子細胞生物学
Research InstitutionOchanomizu University

Principal Investigator

MUROFUSHI Kimiko  Ochanomizu University, Department of Biology, Assistant Professor, 理学部, 講師 (00103557)

Project Period (FY) 1991 – 1993
Project Status Completed (Fiscal Year 1993)
Budget Amount *help
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1993: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1992: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1991: ¥800,000 (Direct Cost: ¥800,000)
KeywordsNuclear matrix / DNA synthesis / DNA polymerase / Microtubule-associated proteins (MAPs) / DNA replication machinery / DNAポリメラーゼα
Research Abstract

The nuclear matrix plays a role as the site of DNA replication in eukaryotic cells. It was found that multi-enzyme complexes including DNA polymerase alpha, one of the replicative enzymes of eukaryotes, were associated with the matrix, and the matrix isolated from a true slime mold, Physarum polycephalum, was able to catalyze the formation of replication intermediates in vitro. Similar stimulation occurred in the nuclear matrices isolated from HeLa cells and rat ascites hepatoma cells. DNA polymerase alpha bound to a MAP-immobilized column, whereas preincubation of the enzyme with unbound MAPs prevented binding to the column. Kinetic analyzes revealed that MAPs decreased the Km value of the polymerase for deoxyribonucleoside triphosphates, irrespective of the species of template-primer. Product analyzes showed that MAPs did not alter the processivity of the polymerase and the increment of Vmax is considered to be due to an increase in the frequency of initiation of DNA synthesis. These findings indicate that a putative DNA replication machinery including DNA polymerase alpha exists on the matrix.
MAPs, which are the general term for the accessory proteins associated with microtubules, one of the major cytoskeletal components, stimulated DNA synthesis catalyzed by the nuclear matrix isolated from Physarum polycephalum in the presence of activated DNA as exogenous templates. MAPs also stimulated DNA polymerase alpha activity solubilized from nuclei, but not DNA polymerase beta activity. MAPs stimulates DNA synthesis by interacting with the putative DNA replication machinery including DNA polymerase alpha bound to the matrix. Kinetic analyzes showed that MAPs decreases the Km value of the matrix for deoxyribonucleoside triphosphates. Comparison of the Km values of active- and latent-type DNA replication machineries of Physarum suggested a possible role for MAPs or MAP-like proteins in DNA replication.

Report

(4 results)
  • 1993 Annual Research Report   Final Research Report Summary
  • 1992 Annual Research Report
  • 1991 Annual Research Report
  • Research Products

    (14 results)

All Other

All Publications (14 results)

  • [Publications] Okuhara,K.,et al.: "Initiation of DNA synthesis in a high molecular weight fraction of Xenopus egg extract." Cell Biology International. 17. 275-282 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Shioda,M.,et al.: "Modulation of DNA synthesis by microtubule-associated proteins in the nuclear matrix isolated from Physarum polycephalum." Biochemistry and Molecular Biology International. 31. 905-910 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Uchiyama,N.,et al.: "Characterization of nuclear,and nuclear matrix-bound DNA polymerases of normal rat liver." Natural Science Report of the Ochanomizu Univrsity. 45(印刷中). (1994)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Shioda, M., Okuhara, K., Murofushi, H., Mori, A., Sakai, H., Murakami-murofushi, K., Suzuki, M., and Yoshida, S.: "Stimulation of DNA polymerase alpha activity by microtubule-associated proteins." Biochemistry. 30. 11403-11412 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Shimada, Y., Murakami-Murofushi, K., Ohta, J., and Shioda, M.: "Extracellular polysaccharide from a true slime mold, Physarum polycphalum." Nat.Sci.REp.Ochanomizu Univ.42. 49-56 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Okuhara, K., Shioda, M., Shiokawa, K., Murakami-Murofushi, K., Seyama, Y., and Murofushi, H.: "Initiation of DNA synthesis in a high molecular weight fraction of Xenopus egg extract." Cell Biol.Int.17. 275-282 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Shioda, M., Okuhara, K., Murakami-Murofushi, K., and Murofushi, H.: "Modulation of DNA synthesis by microtubule-associated proteins in the nuclear matrix isolated from Physarum polycephalum." Biochem.Mol.Biol.Int.31. 905-910 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Uchiyama, N., Kohyama, N., Shimada, Y., and Murakami-Murofushi, K.: "Characterization of nuclear, and nuclear matrix-bound DNA polymerases of normal rat liver." Nat.Sci.Rep.Ochanomizu Univ.45 (in press).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] Okuhara,K.,et al.: "Initiation of DNA synthesis in a high molecular weight fraction of Xenopus egg extract." Cell Biology International. 17. 275-282 (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] Shioda,M.,et al.: "Modulation of DNA synthesis by microtubule-associated proteins in the nuuclear matrix isolated from Physarum polycephalum." Biochemistry and Molecular Biology International. 31. 905-910 (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] Uchiyama,N.,et al.: "Characterization of nuclear,and nuclear matrix-bound DNA polymerases of normal rat liver." Natural Science Report of the Ochanomizu Univrsity. 45(印刷中). (1994)

    • Related Report
      1993 Annual Research Report
  • [Publications] Murakami-Murofushi,K.,et al: "Inhibition of Eukaryotic DNA polymeraseα with A Novel Lysophosphatidic Acid (PHYLPA) Isolated from Myxoamoelae of Physurum polycephalum." J.Biol,Chem.267. 21512-21517 (1992)

    • Related Report
      1992 Annual Research Report
  • [Publications] Okuhara,K.,et al: "Initiation of DNA Syutlesis in A High Molecular Weight Fraction of Xenopus Egg Extract." Cell Biol.Int,Rep.(1993)

    • Related Report
      1992 Annual Research Report
  • [Publications] Shioda,M.et al: "Stimulation of DNA polymerase α activity by microtubuleーassociated proteins." Biochemistry. (1991)

    • Related Report
      1991 Annual Research Report

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Published: 1991-04-01   Modified: 2016-04-21  

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