The role of collagen-specific molecular chaperone HSP47

胶原蛋白特异性分子伴侣HSP47的作用

基本信息

批准号：
06044125
负责人：
NAGATA Kazuhiro
金额：
$ 5.44万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06044125/
关键词：
stress protein HSP47 procollagen molecular chaperone コラーゲン細胞内輸送

项目摘要

HSP47 was originally identified as a collagen-specific stress protein located in the endoplasmic reticulum (ER). HSP47 binds to procollagen in the ER immediately after the nascent chain of procollagen enters the ER and dissociates from it in the cis-Golgi network. Binding affinity of HSP47 to various types of collagens including types I to V was revealed to be similar using BIAcore biosensor. The expression of HSP47 closely correlates with that of collagens including types I to IV in various cell lines and during the development of mouse embryos. Both HSP47 and types I and III collagens were also induced in some pathological conditions such as during the progression of liver fibrosis caused by the administration of carbon tetrachrolide into rats.We showed the results of the transfection of antisense RNA for HSP47 into BALB c/3T3 cells. We obtained several stable transfectants where the synthesis and accumulation of HSP47 were inhibited moderately and almost completely. The expression of procollagen was observed to be inhibited at levels of both protein synthesis and mRNA accumulation in the cells containing low level of HSP47. In addition to the inhibition of collagen synthesis, the secretion of procollagen was inhibited in these cells although the inhibition was not so evident because of the low level of collagen synthesis. Next, we tried to transfect the cDNA encoding al chain of type I collagen into the HSP47-antisense transfected cells. In this double transfectants, the level of HSP47 was low while the amount of procollagen al chain was comparable with that of control cells. In these cells, we found that procollagen was recovered in the detergent-insoluble fraction, indicating that HSP47 is involved in the solubility of a chains of procollagen in the ER.

HSP47最初被鉴定为位于内质网（ER）中的胶原特异性应激蛋白。 HSP47在procollagen的新生链进入ER并在CIS-Golgi网络中分离出来后立即与ER中的Procollagen结合。 HSP47与包括I型V到V（V型）的各种胶原的结合亲和力相似，使用biacore BioSensor。 HSP47的表达与胶原蛋白的表达与包括I型至IV的胶原蛋白的表达密切相关，在各种细胞系和小鼠胚胎的发展过程中。 HSP47和I型和III型胶原蛋白也在某些病理条件下也被诱导，例如在肝纤维化的过程中，由四酚碳施用到大鼠中引起的肝纤维化进展。我们显示了HSP47对BALB C/3T3细胞的抗义RNA转染的结果。我们获得了几种稳定的转染物，其中HSP47的合成和积累几乎完全抑制。观察到在蛋白质合成的水平和含有低水平HSP47水平的细胞中的蛋白质合成水平和mRNA积累水平上，胶原素的表达被抑制。除了抑制胶原蛋白合成外，这些细胞的分泌在这些细胞中被抑制，尽管由于胶原蛋白的合成水平较低，因此抑制作用并不那么明显。接下来，我们试图将编码I型胶原蛋白链的cDNA转染到HSP47抗抗转染的细胞中。在此双重转染剂中，HSP47的水平较低，而procollagen al链的量与对照细胞的链含量相当。在这些细胞中，我们发现在洗涤剂不溶的部分中回收了胶原素，这表明HSP47参与了ER中Procollagen链的溶解度。