Mechanism for the Organization of the Golgi apparatus

高尔基体的组织机制

• 批准号: 11480183
• 负责人: TAGAYA Mitsuo
• 金额: $ 8.9万
• 依托单位: Tokyo University of Pharmacy & 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: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11480183/
• 关键词: Golgi apparatus; retrograde transport; trimeric GTP-binding protein; endoplasmic reticulum; ceramide; phospholipase; membrane fusion; 膜融合syntaxin

The Golgi apparatus consisting of stacks of cisternae is a station for the transit of secretory proteins. Membranes flow into and out from the Golgi apparatus as secretary proteins are transported from the endoplasmic reticulum to the plasma membrane through this organelle. In addition, membrane efflux occurs in accordance with retrograde transport from the Golgi to the endoplasmic reticulum. In spite of massive membrane flow, the structure of the Golgi apparatus is maintained during the interphase of mammalian cells. The purpose of the present project is to elucidate the mechanism of the organization of the Golgi apparatus, and to identify new proteins involved in vesicular transport in the early secretory pathway. The following results were obtained.1. Nordihydroguaiaretic acid-induced Golgi disassembly was prevented by overexpression of Gαi2 or Gαz, but not other Gα species. Expression of RGS (regulator of G-protein signaling) proteins specific for Gαz also caused Golgi disassembly, suggesting that the active form of Gαz plays a role in the maintenance of the Golgi apparatus.2. Short chain ceramide blocked Golgi disassembly caused by Golgi-disrupting reagents such as brefeldin A, whereas long chain ceramide enhanced their effects. This suggests that sphingolipid metabolism is implicated in the stability of the Golgi apparatus.3. A novel protein termed p125 that can interact with a subunit of COPII, Sec23p, was isolated. It possesses a Pro-rich region and a phospholipase A domain. p125 was colocalized with a tethering protein, p115. A data base search revealed the presence of a protein (KIAA0725p) which shows high similarity to p125.4. A novel syntaxin species (syntaxin 18) localized in the endoplasmic reticulum was identified. Syntaxin 18 is possibly involved in the retrograde transport. Several syntaxin 18-binding proteins were identified and their characterization is now in progress.

由库斯特纳（Cisternae）组成的高尔基体是一个用于秘密蛋白质过境的站点。膜从高尔基体从高尔基体流入和流出来，因为秘书蛋白通过该细胞器从内质网传输到质膜。此外，膜外排是根据从高尔基体到内质网的逆行转运而发生的。尽管有巨大的膜流，但在哺乳动物细胞的相间，高尔基体的结构仍保持。本项目的目的是阐明高尔基体组织的机制，并确定在早期秘密途径中参与水泡运输的新蛋白质。获得以下结果1。通过过度表达GαI2或GαZ，而不是其他Gα物种，可以防止北多糖蛋白酸诱导的高尔基体拆卸。针对GαZ的RGS（G蛋白信号传导调节剂）的表达也引起了高尔基体拆卸，这表明GαZ的活性形式在维持高尔基体设备中起作用。2。短链神经酰胺阻止了由诸如Brefeldin A之类的高尔基脱离试剂引起的高尔基体拆卸，而长链神经酰胺则增强了其作用。这表明高尔基体的稳定性暗示了鞘脂代谢3。一种称为p125的新型蛋白质可以与Copii亚基Sec23p相互作用。它具有富含亲磷脂的区域和磷脂酶A结构域。 P125与束缚蛋白P115共定位。数据库搜索揭示了与P125.4相似的蛋白质（KIAA0725P）的存在。鉴定了一种局部在内质网中的新型义话素种（语法18）。语法18可能参与逆行运输。鉴定了几种索引素18结合蛋白，并且它们的表征正在进行中。

项目成果

Kuroiwa,K. et al.: "Arachidonyltrifluoromethy ketone, a phospholipase A_2 antagonist, induces dispersal of both Golgi stack-and trans Golgi network-resident proteins throughout the cytoplasm."Biochem.Biophys.Res.Commun.. 281. 582-588 (2000)

黑岩，K.

Yamaguchi,T.et al.: "Regulation of the Golgi structure by the a-subunits of heterotrimeric G proteins"FEBS Lett.. (in press).

Yamaguchi,T.et al.：“异源三聚体 G 蛋白的 a 亚基对高尔基体结构的调节”FEBS Lett..（出版中）。

Mizoguchi,T. et al.: "Determination of functional regions of p125, a novel mammalian Sec23p-interacting protein."Biochem.Biophys.Res.Commun.. 279. 144-149 (2000)

沟口，T.

Tani, K.et al.: "p125 is a novel mammalian Sec23p-interacting protein with structural similarity to phospholipid-modifying proteins."J.Biol.Chem.. 274. 20505-50512 (1999)

Tani, K. 等人：“p125 是一种新型哺乳动物 Sec23p 相互作用蛋白，其结构与磷脂修饰蛋白相似。”J.Biol.Chem.. 274. 20505-50512 (1999)

Hatsuzawa,K.et al.: "Syntaxin 18:a SNARE that functions in the ER,intermediate compartment,and cis-Golgi vesicle trafficking"J.Biol.Chem.. (in press).

Hatsuzawa,K.et al.：“Syntaxin 18：在 ER、中间室和顺式高尔基体囊泡运输中发挥作用的 SNARE”J.Biol.Chem..（出版中）。