Collagen processing and molecular chaperones : molecular anatomy based on the domain structures

胶原蛋白分子的翻译后加工与分子伴侣的功能有关。我们首先研究了热休克蛋白47（一种胶原特异性分子伴侣）在瘢痕形成中的作用，即由创伤引发的过度和异常的胶原合成。我们发现，热休克蛋白47以及I型胶原在胎鼠伤口中没有诱导，相反，它们在新生大鼠伤口中的增强。因此，我们试图通过抗治疗治疗来抑制胶原沉积。其结果是，新生大鼠创伤后的瘢痕形成有效地防止了针对Hsp 47的反义寡核苷酸在体外（原代培养的成纤维细胞）和体内（背部伤口）。这些结果表明，Hsp 47可能是一个潜在的目标，防止瘢痕形成的外科手术，如腭裂。我们还探讨了Hsp 90的功能机制。E.大肠杆菌HtpG是哺乳动物Hsp 90的同源物， ...更多信息 在一级结构水平上与人Hsp 90的结构域相同。N端、中间和C端结构域分别称为N、M和C结构域。Hsp 90的客户端结合活性主要定位于N结构域。结构域之间存在两种相互作用：N和M结构域之间的分子内相互作用; M和C结构域之间的分子间相互作用。后者的相互作用介导的热休克蛋白90的二聚体形成。前一种相互作用的释放伴随着热休克蛋白90分子伴侣的客户端结合活性的高温诱导的激活。也就是说，位于N结构域的客户端结合位点被M结构域隐藏，但热休克破坏了这种相互作用。通过表达M结构域不能与N结构域相互作用的异常酵母HSP 90（Hsc 82），证实了N结构域和M结构域相互作用的重要性。因此，我们提出的热诱导激活的热休克蛋白90分子伴侣的分子内相互作用的解放的机制。少

Post-translational processing of collagen molecules has been investigated in relation to the function of molecular chaperones. We first investigated the role of Hsp47, a collagen specific molecular chaperone, in scar formation, i.e. excessive and aberrant collagen synthesis triggered by the wounding. We found that Hsp47 as well as type I collagen was not induced in fetal rat wound, in contrast to their enhancement in neonatal rat wound. Hence, we tried to suppress collagen deposition by anti-therapeutic treatment. As a result, scar formation after wounding of neonatal rats was efficiently prevented by an anti-sense oligonucleotide against Hsp47 in vitro (primary-cultured fibroblasts) and in vivo (back wound). These findings strongly suggested that Hsp47 could be a potential target for prevention of scar formation on surgical operations, such as cleft palate.We also investigated the functional mechanism of Hsp90. E. coli HtpG, a bacterial homologue of mammalian Hsp90, was composed of th … More ree domains at the primary structure level as those of human Hsp90. The N-terminal, middle and C-terminal domains were referred to N, M and C domains, respectively. The client-binding activity of Hsp90 was primarily localized in N domain. There were two interactions between the domains : an intramolecular interaction between N and M domains ; and an intermolecular interaction between M and C domains. The latter interaction mediated dimer formation of HSP90. Liberation of the former interaction accompanied the high temperature-induced activation of the client-binding activity of Hsp90 molecular chaperone. That is, the client-binding site located in N domain was concealed by M domain, but heat shock disrupted the interaction. Importance of the interaction between N and M domains was confirmed by expression of aberrant yeast HSP90 (Hsc82), of which M domain could not interact with N domain. We therefore propose the liberation of the intra-molecular interaction as the mechanism of heat-induced activation of Hsp90 molecular chaperone. Less