Studies on dynamics of nascent proteins upon folding

新生蛋白质折叠动力学研究

• 批准号: 12480183
• 负责人: WADA Ikuo
• 金额: $ 8.06万
• 依托单位: Sapporo Medical University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12480183/
• 关键词: Endoplasmic reticulum; Folding; COP II; Quality control; Membrane dynamics; 酸化; 構造形成; チロシナーゼ; COPII顆粒

1. Some misfolded proteins in the secretory pathway are degraded at the level of the endoplasmic reticulum (ER) by proteasome. We reported that a novel protein, EDEM, accelerates the proteasoome-mediated degradation. Because EDEM is likely an inactive form of ER mannosidasel, we suggested that EDEM may be a receptor for misfolded proteins bearing Man8 oligosaccharides.2. Folded secretory proteins are exported from the transitional elements of the ER (tER). We reported that the process is inhibited by diacylglycerol kinase delta (DGKd) whose functon had not been assigned. The action appeared to be mediated by attachment of COPII coat to tER. Targetting of DGKd requires C-terminus SAM domain, and, suprisingly, does not require the enzyme activity but depends on N-termmus PH domain.3.Oculocytanous albinism type I (OCA I) is caused by mutations of tyrosinase. We reported that tyrosinase OCAI mutants are retained-in the ER until dissociation from calnexin and immediately degraded by proteasome. Furthermore, we reported that wild type tyrosinase is retained in the ER by mutations in tyrosinase-related protein-1, which seems to a molecular basis for OGA3.4. We found that the degradtion accelarated by EDEM does not involve recycling through ERGIC but the one stimulated by ER mannosidase I requires recycling.

1. 分泌途径中的一些错误折叠的蛋白质在内质网（ER）水平被蛋白酶体降解。我们报道了一种新的蛋白质 EDEM，可以加速蛋白酶体介导的降解。由于EDEM可能是ER甘露糖苷酶的无活性形式，我们认为EDEM可能是含有Man8寡糖的错误折叠蛋白的受体。2．折叠的分泌蛋白从 ER 的过渡元件 (tER) 输出。我们报道了该过程被二酰基甘油激酶δ（DGKd）抑制，其功能尚未指定。该作用似乎是通过 COPII 外壳与 tER 的附着介导的。 DGKd的靶向需要C端SAM结构域，令人惊讶的是，它不需要酶活性，而是依赖于N端PH结构域。3.眼细胞白化病I型(OCA I)是由酪氨酸酶突变引起的。我们报道了酪氨酸酶 OCAI 突变体保留在 ER 中，直到与钙联蛋白解离并立即被蛋白酶体降解。此外，我们报道野生型酪氨酸酶通过酪氨酸酶相关蛋白1的突变保留在ER中，这似乎是OGA3.4的分子基础。我们发现 EDEM 加速的降解不涉及通过 ERGIC 的回收，但 ER 甘露糖苷酶 I 刺激的降解需要回收。

项目成果

Oyadomari, S. et al.: "Nitric oxide-induced apoptosis in pancreatic -cells is mediated by the endoplasmic reticulum stress pathway"Proc.Natl.Acad.Sci.U.S.A.. 98. 10845-10850 (2001)

Oyadomari，S.等人：“一氧化氮诱导的胰腺细胞凋亡是由内质网应激途径介导的”Proc.Natl.Acad.Sci.U.S.A.. 98. 10845-10850 (2001)

Taniguchi, T. et al.: "A critical role for the carboxy terminal region of the proprotein convertase, PACE4A, in the regulation of its autocatalytic activation coupled with secretion"Biochem, Biophys. Res. Com.. 290(2). 878-884 (2002)

Taniguchi, T. 等人：“前蛋白转化酶 PACE4A 的羧基末端区域在调节其自催化激活和分泌方面发挥着关键作用”Biochem，Biophys。

Ikawa, M. et al.: "Calmegin is required for fertilin alpha/beta heterodimerization and sperm fertility"Dev.Biol.. 240. 254-261 (2001)

Ikawa, M. 等人：“Calmegin 是生育素 α/β 异二聚化和精子生育能力所必需的”Dev.Biol.. 240. 254-261 (2001)

Toyofuku, K. et al.: "Oculocutaneous albinism types 1 and 3 are ER retention diseases: mutation of tyrosinase or tyrpl can affect the processing of both mutant and wild-type proteins"FASEB J.. 15・12. 2149-2161 (2001)

Toyofuku, K. 等人：“1 型和 3 型眼皮肤白化病是 ER 滞留疾病：酪氨酸酶或 tyrp1 的突变会影响突变型和野生型蛋白质的加工”FASEB J.. 15・12（ 2001）

Toyofuku, K. et al.: "Oculocutaneous albinism types 1 and 3 are ER retention diseases: mutation of tyrosinase or tyrp 1 can affect the processing of both mutant and wild-type proteins."FASEB J.. 15(12). 2149-2161 (2001)

Toyofuku, K. 等人：“1 型和 3 型眼皮肤白化病是 ER 滞留疾病：酪氨酸酶或酪氨酸 1 的突变可以影响突变型和野生型蛋白质的加工。”FASEB J.. 15(12)。