Marszalek Jaroslaw, Craig Elizabeth A
Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland.
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States.
Front Mol Biosci. 2022 Oct 12;9:1034453. doi: 10.3389/fmolb.2022.1034453. eCollection 2022.
In cells molecular chaperone systems consisting of Hsp70 and its obligatory J-domain protein (JDP) co-chaperones transiently interact with a myriad of client proteins-with JDPs typically recruiting their partner Hsp70 to interact with particular clients. The fundamentals of this cyclical interactions between JDP/Hsp70 systems and clients are well established. Much less is known about other aspects of JDP/Hsp70 system function, including how such systems evolved over time. Here we discuss the JDP/Hsp70 system involved in the biogenesis of iron-sulfur (FeS) clusters. Interaction between the client protein, the scaffold on which clusters are built, and its specialized JDP Hsc20 has stayed constant. However, the system's Hsp70 has changed at least twice. In some species Hsc20's Hsp70 partner interacts only with the scaffold, in others it has many JDP partners in addition to Hsc20 and interacts with many client proteins. Analysis of this switching of Hsp70 partners has provided insight into the insulation of JDP/Hsp70 systems from one another that can occur when more than one Hsp70 is present in a cellular compartment, as well as how competition among JDPs is balanced when an Hsp70 partner is shared amongst a number of JDPs. Of particularly broad relevance, even though the scaffold's interactions with Hsc20 and Hsp70 are functionally critical for the biogenesis of FeS cluster-containing proteins, it is the modulation of the Hsc20-Hsp70 interaction that allows Hsc20 to function with such different Hsp70 partners.
在细胞中，由热休克蛋白70（Hsp70）及其必需的J结构域蛋白（JDP）共伴侣组成的分子伴侣系统与众多客户蛋白发生瞬时相互作用，其中JDP通常会招募其伴侣Hsp70与特定客户蛋白相互作用。JDP/Hsp70系统与客户蛋白之间这种循环相互作用的基本原理已得到充分确立。对于JDP/Hsp70系统功能的其他方面，包括这些系统如何随时间演变，人们了解得要少得多。在这里，我们讨论参与铁硫（FeS）簇生物合成的JDP/Hsp70系统。客户蛋白（即构建簇的支架）与其专门的JDP Hsc20之间的相互作用一直保持不变。然而，该系统的Hsp70至少发生了两次变化。在某些物种中，Hsc20的Hsp70伴侣仅与支架相互作用，而在其他物种中，它除了与Hsc20相互作用外，还有许多JDP伴侣，并与许多客户蛋白相互作用。对Hsp70伴侣这种切换的分析，有助于深入了解当细胞区室中存在不止一种Hsp70时，JDP/Hsp70系统之间可能发生的相互隔离，以及当一个Hsp70伴侣被多个JDP共享时，JDP之间的竞争是如何平衡的。特别具有广泛相关性的是，尽管支架与Hsc20和Hsp70的相互作用对于含FeS簇蛋白的生物合成在功能上至关重要，但正是Hsc20-Hsp70相互作用的调节使得Hsc20能够与如此不同的Hsp70伴侣发挥作用。
