Two novel chaperone-like proteins involved in ER quality control mechanism

两种新型伴侣蛋白参与 ER 质量控制机制

• 批准号: 13308042
• 负责人: NAGATA Kazuhiro
• 金额: $ 33.95万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13308042/
• 关键词: Molecular Chaperone; Quality control of proteins; ER associated degradation; EDEM; ER mannosidase; HSP47; collagen

We found and cloned the gene of a novel stress protein HSP47 which resides in the endoplasmic reticulum (ER) acting as a collagen-specific molecular chaperone in the pathway of collagen biosynthesis, processing and secretion. HSP47 specifically and transiently binds to various types of collagen in the ER. We already succeeded in making knockout mice lacking hsp47 gene, which result in causing the embryonic lethality at 10.5 dpc in hsp47-/-homozygotic mice. In these homozygotic mice, the maturation of type I and type IV collagens was abnormal and the formation of collagen fibrils and basement membranes was impaired suggesting that HSP47 is essential molecular chaperone for collagen.We are also working on ER quality control mechanism, especially on mouse EDEM protein that we have cloned. It is known that misfolded or abnormal proteins accumulated in the ER are retrotranslocated to the cytosol for degradation, and EDEM is expected to play an important role in this process. EDEM recognize only misfolded proteins as substrates in collaboration with calnexin, a molecular chaperone in the ER, and accelerate their degradation. We recently found and cloned the functional homologues of EDEM, soluble EDEM and EDEM3, and now analyzing their functions in ER associated degradation.

我们发现并克隆了一种新的应激蛋白HSP 47的基因，它位于内质网（ER）中，在胶原的生物合成、加工和分泌过程中起胶原特异性分子伴侣的作用。HSP 47特异性地和瞬时地结合ER中的各种类型的胶原。我们已经成功地制造了hsp 47基因敲除小鼠，导致hsp 47-/-纯合子小鼠在10.5 dpc时胚胎死亡。在这些纯合子小鼠中，I型和IV型胶原的成熟异常，胶原纤维和基底膜的形成受损，这表明HSP 47是胶原的必需分子伴侣。研究表明，错误折叠或异常的蛋白质在内质网中聚集后会被逆向转运到胞质中降解，而EDEM在这一过程中可能发挥重要作用。EDEM仅识别错误折叠的蛋白质作为与钙连接蛋白（ER中的分子伴侣）协作的底物，并加速其降解。我们最近发现并克隆了EDEM的功能同源物，可溶性EDEM和EDEM 3，并正在分析它们在ER相关降解中的功能。

项目成果

S.OHASHI: "Advanced glycation end products increase collagen-specific chaperone protein in mouse diabetic nephropathy"J.Biol.Chem.. (in press).

S.OHASHI：“高级糖基化终末产物增加小鼠糖尿病肾病中胶原蛋白特异性伴侣蛋白”J.Biol.Chem..（出版中）。

K.NAGATA: "HSP47 as a collagen-specific molecular chaperone : function and expression in normal mouse development"Seminars in Cell and Developmental Biology. 14. 275-282 (2003)

K.NAGATA：“HSP47 作为胶原蛋白特异性分子伴侣：正常小鼠发育中的功能和表达”细胞和发育生物学研讨会。

S.MURAKAMI: "Heat shock protein(HSP)47 and collagen are upregulated during neointimal formation in the balloon-injured rat carotid artery"Atherosclerosis. 157. 361-368 (2001)

S.MURAKAMI：“热休克蛋白 (HSP)47 和胶原蛋白在球囊损伤的大鼠颈动脉的新内膜形成过程中上调”动脉粥样硬化。

H.YOSHIDA, T.MATSUI, N.HOSOKAWA, R.J.KAUFMAN, K.NAGATA, K.MORI: "A. time-dependent phase shift in the mammalian unfolded proten response"Develop.Cell.. 4(2). 265-271 (2003)

H.YOSHIDA、T.Matsui、N.Hosokawa、R.J.KAUFMAN、K.NAGATA、K.MORI：“哺乳动物未折叠蛋白反应中的时间依赖性相移”Develop.Cell.. 4(2)。

M.KIKUCHI: "A single chain Fv fragment 2A3 specific for native lysozyme : Isolation from a human synthetic phage display antibody library and characterization"J. Biochem.. 129. 237-242 (2001)

M.KIKUCHI：“对天然溶菌酶具有特异性的单链 Fv 片段 2A3：从人类合成噬菌体展示抗体库中分离并表征”J.