Baindur-Hudson Swati, Edkins Adrienne L, Blatch Gregory L
College of Health and Biomedicine, Victoria University, VIC 8001, Melbourne, Australia,
Subcell Biochem. 2015;78:69-90. doi: 10.1007/978-3-319-11731-7_3.
The Hsp70/Hsp90 organising protein (Hop), also known as stress-inducible protein 1 (STI1), has received considerable attention for diverse cellular functions in both healthy and diseased states. There is extensive evidence that intracellular Hop is a co-chaperone of the major chaperones Hsp70 and Hsp90, playing an important role in the productive folding of Hsp90 client proteins. Consequently, Hop is implicated in a number of key signalling pathways, including aberrant pathways leading to cancer. However, Hop is also secreted and it is now well established that Hop also serves as a receptor for the prion protein, PrP(C). The intracellular and extracellular forms of Hop most likely represent two different isoforms, although the molecular determinants of these divergent functions are yet to be identified. There is also a growing body of research that reports the involvement of Hop in cellular activities that appear independent of either chaperones or PrP(C). While Hop has been shown to have various cellular functions, its biological function remains elusive. However, recent knockout studies in mammals suggest that Hop has an important role in embryonic development. This review provides a critical overview of the latest molecular, cellular and biological research on Hop, critically evaluating its function in healthy systems and how this function is adapted in diseases states.
热休克蛋白70/热休克蛋白90组织蛋白（Hop），也被称为应激诱导蛋白1（STI1），因其在健康和疾病状态下的多种细胞功能而受到广泛关注。有大量证据表明，细胞内的Hop是主要伴侣蛋白热休克蛋白70（Hsp70）和热休克蛋白90（Hsp90）的共伴侣蛋白，在Hsp90客户蛋白的有效折叠中发挥重要作用。因此，Hop与许多关键信号通路有关，包括导致癌症的异常通路。然而，Hop也会分泌，并且现在已经明确Hop还作为朊病毒蛋白PrP(C)的受体。Hop的细胞内和细胞外形式很可能代表两种不同的异构体，尽管这些不同功能的分子决定因素尚未确定。也有越来越多的研究报道Hop参与了一些似乎独立于伴侣蛋白或PrP(C)的细胞活动。虽然Hop已被证明具有多种细胞功能，但其生物学功能仍然难以捉摸。然而，最近在哺乳动物中的基因敲除研究表明，Hop在胚胎发育中起重要作用。本综述对Hop的最新分子、细胞和生物学研究进行了批判性概述，严格评估了其在健康系统中的功能以及这种功能在疾病状态下是如何变化的。
