著者

Yoshimura Shige H. Kumeta Masahiro Takeyasu Kunio

出版者

Elsevier Ltd.

雑誌

Structure (ISSN:09692126)

巻号頁・発行日

vol.22, no.12, pp.1699-1710, 2014-11

被引用文献数

28

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タンパク質が核膜孔を通り抜ける際の構造変化を解明 -細胞核内部への遺伝子導入技術への応用に期待-. 京都大学プレスリリース. 2014-11-27.

著者

Uemura Tomohiro Ueda Takashi Ohniwa Ryosuke L. Nakano Akihiko Takeyasu Kunio Sato Masa H.

出版者

日本細胞生物学会

雑誌

Cell Structure and Function

巻号頁・発行日

vol.29, no.2, pp.49-65, 2004

被引用文献数

448

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In all eucaryotic cells, specific vesicle fusion during vesicular transport is mediated by membrane-associated proteins called SNAREs (soluble N-ethyl-maleimide sensitive factor attachment protein receptors).<br> Sequence analysis identified a total of 54 SNARE genes (18 Qa-SNAREs/Syntaxins, 11 Qb-SNAREs, 8 Qc-SNAREs, 14 R-SNAREs/VAMPs and 3 SNAP-25) in the <i>Arabidopsis</i> genome. Almost all of them were ubiquitously expressed through out all tissues examined. A series of transient expression assays using green fluorescent protein (GFP) fused proteins revealed that most of the SNARE proteins were located on specific intracellular compartments: 6 in the endoplasmic reticulum, 9 in the Golgi apparatus, 4 in the <i>trans</i>-Golgi network (TGN), 2 in endosomes, 17 on the plasma membrane, 7 in both the prevacuolar compartment (PVC) and vacuoles, 2 in TGN/PVC/vacuoles, and 1 in TGN/PVC/plasma membrane.<br> Some SNARE proteins showed multiple localization patterns in two or more different organelles, suggesting that these SNAREs shuttle between the organelles. Furthermore, the SYP41/SYP61-residing compartment, which was defined as the TGN, was not always located along with the Golgi apparatus, suggesting that this compartment is an independent organelle distinct from the Golgi apparatus. We propose possible combinations of SNARE proteins on all subcellular compartments, and suggest the complexity of the post-Golgi membrane traffic in higher plant cells.<br>

著者

Yoshikawa Yuko Hizume Kohji Oda Yoshiko Takeyasu Kunio Araki Sumiko Yoshikawa Kenichi

出版者

Biophysical Society

雑誌

Biophysical Journal (ISSN:00063495)

巻号頁・発行日

vol.90, no.3, pp.993-999, 2006-02

被引用文献数

36

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Direct attack to genomic DNA by reactive oxygen species causes various types of lesions, including base modi. cations and strand breaks. The most significant lesion is considered to be an unrepaired double-strand break that can lead to fatal cell damage. We directly observed double-strand breaks of DNA in reconstituted chromatin stained by a fluorescent cyanine dye, YOYO (quinolinium, 1, 1 '-[1, 3-propanediylbis[(dimethyliminio)-3, 1- propanediyl]]bis[4-[(3-methyl-2(3H)-benzoxazolylidene) methyl]]-, tetraiodide), in solution, where YOYO is known to have the ability to photo-cleave DNAs by generating reactive oxygen species. Reconstituted chromatin was assembled from large circular DNA (106 kbp) with core histone proteins. We also investigated the effect of vitamin C ( ascorbic acid) on preventing photo-induced double-strand breaks in a quantitative manner. We found that DNA is protected against double-strand breaks by the addition of ascorbic acid, and this protective effect is dose dependent. The effective kinetic constant of the breakage reaction in the presence of 5 mM ascorbic acid is 20 times lower than that in the absence of ascorbic acid. This protective effect of ascorbic acid in reconstituted chromatin is discussed in relation to the highly compacted polynucleosomal structure. The results highlight the fact that single-molecule observation is a useful tool for studying double-strand breaks in giant DNA and chromatin.