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- Takusagawa Mari
- Graduate School of Humanities and Sciences, Nara Women's University
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- Hayashi Tomomi
- Department of Biology, Faculty of Science, Nara Women's University
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- Takano Hiroyoshi
- Graduate School of Science and Technology, Kumamoto University Bioelectrics Research Center, Kumamoto University
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- Sakai Atsushi
- Department of Biology, Faculty of Science, Nara Women's University
抄録
The molecular organization of mitochondrial-nucleoids (mt-nucleoids) isolated from BY-2 cultured tobacco (Nicotiana tabacum L.) cells was analyzed. Fluorescence microscopy using 4′,6-diamidino-2-phenylindole (DAPI) revealed that isolated mt-nucleoids retained the compact structural organization as that observed in vivo. Treatments of mt-nucleoids with DNase I, proteinase K and 2 M NaCl resulted in the disappearance, partial swelling, or complete dispersion of their DAPI-fluorescence, respectively, whereas treatment with RNase A did not affect their compact appearance. These results suggest that the compact structure of mt-nucleoids is maintained by electrostatic interaction between DNA and proteins. When mt-nucleoids that were treated with micrococcal nuclease (MNase) were analyzed by agarose gel electrophoresis, a ladder-like electrophoretic pattern of DNA, whose minimum fragment size was about 75 bp, was observed. This result suggests the presence of nucleosome-like, repetitive structures in the mt-nucleoids. Treatment of mt-nucleoids with increasing concentrations of NaCl gradually solubilized various proteins, including those with DNA-binding activities, which was accompanied by gradual dispersion of the mt-nucleoid structure. This result suggests that a variety of DNA-binding proteins with differing degrees of binding strength are present in the mt-nucleoids, and are involved in the compact organization of DNA-protein complexes at various levels. Detailed analyses of mt-nucleoids by Southwestern blotting, SDS-DNA PAGE, and DNA-cellulose affinity chromatography revealed the presence of many different DNA-binding proteins in the 2 M NaCl-soluble fraction of mt-nucleoids, which are expected to be involved in the compact organization of mt-nucleoids at various levels.
収録刊行物
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- CYTOLOGIA
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CYTOLOGIA 74 (3), 329-341, 2009
公益財団法人 日本メンデル協会
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詳細情報 詳細情報について
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- CRID
- 1390001204108866688
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- NII論文ID
- 130004448063
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- ISSN
- 13487019
- 00114545
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- 本文言語コード
- en
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- データソース種別
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- JaLC
- Crossref
- CiNii Articles
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- 抄録ライセンスフラグ
- 使用不可