A Search for a new chaperone proteins on the endoplasmic retical

在内质网上寻找新的伴侣蛋白

• 批准号: 11680695
• 负责人: HOSOKAWA Nobuko
• 金额: $ 1.66万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 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/grant/KAKENHI-PROJECT-11680695/
• 关键词: Endoplasmic Reticulum; ERADC Endoplasmic reticulum associated degradation; d-Mannosidase; Quality Control of the Endoplasmic Reticulum; Glycoprotein; 小胞体関係連分解; 分子シャペロン; 品質管理機構; 小胞体関連蛋白質分解

In cells, most of the secretory and membrane proteins are synthesized in the endoplasmic reticulum (ER), and only correctly folded proteins are transported to the Golgi apparatus for further processing. There are chaperone proteins such as GRP78, GRP94, calnexin, and calreticulin in the ER, and they assist the folding of newly synthesized or misfolded proteins. Still, it is expected that important chaperone proteins remains to be recovered in the ER.In this study, I searched for new chaperone proteins in the ER, and analyzed its function to clarify the mechanisms of protein folding and the quality control in the ER.To clone new chaperone proteins, I employed supression subtractive hybridization (SSH) method from cells treated with ER stress, because chapereone proteins are expected to be upregulated by ER stress. I focused on an EST clone which was similar to α-mannosidase. After cloning the whole gene of this EST clone, I analyzed the fundction of this gene product in the cells, and named it as EDEM (ER degradation enhancing α-mannosidase-like protein). EDEM accelerated the degradation of misfolded glycoprotein in the ER, depending on the extent of mannose trimming of N-linked oligosaccharides, and expected to be the key molecule of the ER associated degradation or ER quality control.

在细胞中，大多数分泌蛋白和膜蛋白在内质网（ER）中合成，只有正确折叠的蛋白才会被转运到高尔基体进行进一步处理。内质网中有GRP78、GRP94、钙联蛋白和钙网蛋白等伴侣蛋白，它们协助新合成或错误折叠的蛋白质的折叠。尽管如此，预计内质网中仍有重要的伴侣蛋白有待回收。在本研究中，我在内质网中寻找新的伴侣蛋白，并分析其功能，以阐明内质网中蛋白质折叠的机制和质量控制。为了克隆新的伴侣蛋白，我采用抑制消减杂交（SSH）方法从经内质网应激处理的细胞中克隆，因为伴侣蛋白预计会上调 通过 ER 压力。我关注的是与 α-甘露糖苷酶类似的 EST 克隆。在克隆了这个EST克隆的完整基因后，我分析了该基因产物在细胞中的功能，并将其命名为EDEM（ER降解增强α-甘露糖苷酶样蛋白）。 EDEM 加速了 ER 中错误折叠糖蛋白的降解，具体取决于 N-连接寡糖的甘露糖修剪程度，并且有望成为 ER 相关降解或 ER 质量控制的关键分子。

项目成果

Murakami Y, Toda T, Seiki T, Munetomi E, Kondo Y, Sakurai T, Fukukawa Y, Natsuyama M, Nagate T, Hosokawa N, Nagata K.: "Heat shock protein (HSP) 47 and collagen are upregulated during neointimal formation in the baloon-injured rat carotid artery."Atherosc

Murakami Y、Toda T、Seiki T、Munetomi E、Kondo Y、Sakurai T、Fukukawa Y、Natsuyama M、Nagate T、Hosokawa N、Nagata K.：“热休克蛋白 (HSP) 47 和胶原蛋白在新生内膜形成过程中上调

Naitoh M, Hosokawa N, Kubota H, Tanaka T, Shirane H, Sawada M, Nishimura Y, Nagata K.: "Upregulation of HSP47 and collagen type III in the dermal fibrotic disease, keloid."Biochem.Biophys.Res.Commun.. 280. 1316-1322 (2001)

Naitoh M、Hosokawa N、Kubota H、Tanaka T、Shirane H、Sawada M、Nishimura Y、Nagata K.：“真皮纤维化疾病、疤痕疙瘩中 HSP47 和 III 型胶原蛋白的上调。”Biochem.Biophys.Res.Commun。

Nagai N. et al.: "Embryonic lithality of molecular ihaperone Hsp47 knockout mice is associated with defects in collagen biosynthesis."J.Cell Biol.. 150・6. 1499-1505 (2000)

Nagai N. 等人：“分子 ihaperone Hsp47 敲除小鼠的胚胎密度与胶原蛋白生物合成缺陷有关。”J.Cell Biol. 150・6 (2000)。

Matsuda M. et al.: "Molecular cloning of a novel inbiyuitin-like proteiu, UBIN, that binds to ER targeting signal sequences."Biochem.Biophys.Res.Commun.. 280. 535-540 (2001)

Matsuda M. 等人：“分子克隆一种新型 inbiyuitin 样蛋白 UBIN，它与 ER 靶向信号序列结合。”Biochem.Biophys.Res.Commun.. 280. 535-540 (2001)

Naitoh M. et al.: "Upregulation of molecular chaperone HSP47 and collagen typeIII in keloid."Biochem.Biophys.Res,Commun.. (in press). (2001)

Naitoh M. 等人：“疤痕疙瘩中分子伴侣 HSP47 和 III 型胶原蛋白的上调。”Biochem.Biophys.Res,Commun..（出版中）。