Mechanisms of the disassembly and reassembly of organelles during mitosis

有丝分裂过程中细胞器分解和重组的机制

• 批准号: 09480165
• 负责人: TAGAYA Mitsuo
• 金额: $ 8.45万
• 依托单位: Tokyo University of Pharmacy and Life Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09480165/
• 关键词: endoplasmic reticulum; Golgi apparatus; mitosis; membrane fusion; NSF; muclear envelope; trimeric GTP-binding protein; VCP; 核膜; N-エチルマレイミド感受性因子

At the onset of mitosis vesicle-mediated protein transport is inhibited, and organelles such as the Golgi and nuclear envelope are disassembled into small vesicles. At telophase the small vesicles are fused each other to form intact organelles. Although recent studies revealed that NSF and VCP are involved in the fusion of Golgi-derived vesicles, the mechanisms of the assembly and disassembly of organelles have not been fully understood. In the present study we studied the mechanism of the biogenesis of organelles including the nuclear envelope, Golgi apparatus, and endoplasmic reticulum. The followings are the results obtained.1. NSF is associated with the membrane-embedded SNARE complex via SNAP.NSF is localized not only at the Golgi apparatus but also at the nuclear envelope. An antibody against a subunit of the SNARE complex, SNAP-25, inhibits the fusion of nuclear membrane vesicles in vitro, suggesting the involvement of the NSF-SNAP-SNARE complex in the nuclear membrane fusion.2. The Golgi apparatus is disassembled by nordihydroguaiaretic acid in a mechanism dependent on trimeric GTP-binding proteins. This disassembly was suppressed by overexpression of alpha_<12> or alpha_2, but not other species, suggesting the involvement of specific alpha subunits in the organization of this organelle.3. A novel syntaxin species (syntaxin 18) was identified. Syntaxin 18 is most likely a homologue of yeast Ufe1p, a protein involved in the fusion of nuclear or endoplasmic reticulum membranes. The role of syntaxin 18 in the organization of the endoplasmic reticulum is under investigation.

在有丝分裂开始时，囊泡介导的蛋白质运输被抑制，细胞器如高尔基体和核膜被分解成小囊泡。在末期，小泡相互融合形成完整的细胞器。虽然最近的研究表明NSF和VCP参与了高尔基衍生囊泡的融合，但细胞器组装和拆卸的机制尚未完全了解。本文研究了核膜、高尔基体和内质网等细胞器的生物发生机制。得到的结果如下：NSF通过SNAP与膜内的SNARE复合体相关联。NSF不仅局限于高尔基体，而且也局限于核包膜。针对SNARE复合物亚基SNAP-25的抗体在体外抑制核膜囊泡的融合，表明NSF-SNAP-SNARE复合物参与了核膜融合。高尔基体被去二氢愈创木酸分解，其机制依赖于三聚体gtp结合蛋白。α α <12>或α α _2的过表达抑制了这种分解，而其他物种则没有，这表明α α亚基参与了该细胞器的组织。鉴定出一种新的syntaxin （syntaxin 18）。Syntaxin 18很可能是酵母Ufe1p的同源物，Ufe1p是一种参与核膜或内质网膜融合的蛋白质。syntaxin 18在内质网组织中的作用正在研究中。

项目成果

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Mori 等人：“SecA 的氨基末端区域参与 SecG 将蛋白质易位到大肠杆菌膜囊泡中的功能。”

Igarashi, M.et al.: "The soluble N-ethylmaleimide-sensitive factor attached protein receptor complex in growth cones : molecular aspects of the axon terminal development." J.Neurosci.17. 1460-1470 (1997)

Igarashi, M.等人：“生长锥中可溶性 N-乙基马来酰亚胺敏感因子附着蛋白受体复合物：轴突末端发育的分子方面。”

Takuma, et al.: "Evidence for the putative docking/fusion complex of exocytosis in parotid acinar cells." FEBS Lett.404. 34-36 (1997)

Takuma 等人：“腮腺腺泡细胞胞吐作用的假定对接/融合复合物的证据。”

Tani et al.: "Hypothetical protein KIAA0079 is a mammalian homologue of yeast Sec24p." FEBS Letters in press. (in press).

Tani 等人：“假设蛋白 KIAA0079 是酵母 Sec24p 的哺乳动物同源物。”

Yamaguchi, et al.: "Possible involvment of heterotrimeric G proteins in the organization of the Golgi apparatuts." J.Biol.Chem. 272. 25260-25266 (1997)

Yamaguchi 等人：“异源三聚体 G 蛋白可能参与高尔基体的组织。”