The β6/β7 region of the Hsp70 substrate-binding domain mediates heat-shock response and prion propagation.
The β6/β7 region of the Hsp70 substrate-binding domain mediates heat-shock response and prion propagation.
复制标题
Hsp70 底物结合域的 β6/β7 区域介导热冲击反应和朊病毒传播
DOI：
10.1007/s00018-017-2698-3
复制
发表时间：
2018-04
期刊：
影响因子：
--
通讯作者：
Jones GW
中科院分区：
文献类型：
--
作者：
Xu L;Gong W;Cusack SA;Wu H;Loovers HM;Zhang H;Perrett S;Jones GW
Hsp70是一种高度保守的伴侣蛋白，除了提供必要的细胞功能和帮助细胞在各种应激下存活外，也是朊病毒繁殖的关键调节剂。Hsp70由核苷酸结合域（NBD）和底物结合域（SBD）组成。Hsp70的关键功能是通过一个协调atp酶活性和底物结合活性的变构通讯网络受到严格调节。Hsp70构象变化与导致热休克和朊病毒相关表型的功能变化之间的关系尚不清楚。在这里，我们利用酵母[PSI +]系统，结合SBD靶向诱变，研究了Hsp70 SBD关键结构区域的变抗性变化如何导致蛋白质的功能变化，从而转化为朊病毒繁殖和高温生长能力的表型缺陷。我们发现，在SBD的β6和β7区域突变的变体在朊病毒繁殖和热休克表型上存在缺陷，这是由于SBD内部的构象改变。突变体的结构分析确定了潜在的NBD:SBD界面和可能在域间信号转导中起重要作用的关键残基。由于破坏了β6/β7区域和整个SBD， Hsp70表现出多种功能变化，包括atp酶活性失调，蛋白质重组能力降低以及与特定共伴侣和蛋白质底物的相互作用亲和力改变。我们的研究结果将Hsp70的特定结构变化与支撑体内重要表型变化的功能特性的特定变化联系起来。深入了解Hsp70调控的分子机制以及特异性修饰如何导致表型改变，对于开发靶向Hsp70的治疗新药至关重要。本文的在线版本（10.1007/s00018-017-2698-3）包含补充资料，仅供授权用户使用。
Hsp70 is a highly conserved chaperone that in addition to providing essential cellular functions and aiding in cell survival following exposure to a variety of stresses is also a key modulator of prion propagation. Hsp70 is composed of a nucleotide-binding domain (NBD) and substrate-binding domain (SBD). The key functions of Hsp70 are tightly regulated through an allosteric communication network that coordinates ATPase activity with substrate-binding activity. How Hsp70 conformational changes relate to functional change that results in heat shock and prion-related phenotypes is poorly understood. Here, we utilised the yeast [PSI +] system, coupled with SBD-targeted mutagenesis, to investigate how allosteric changes within key structural regions of the Hsp70 SBD result in functional changes in the protein that translate to phenotypic defects in prion propagation and ability to grow at elevated temperatures. We find that variants mutated within the β6 and β7 region of the SBD are defective in prion propagation and heat-shock phenotypes, due to conformational changes within the SBD. Structural analysis of the mutants identifies a potential NBD:SBD interface and key residues that may play important roles in signal transduction between domains. As a consequence of disrupting the β6/β7 region and the SBD overall, Hsp70 exhibits a variety of functional changes including dysregulation of ATPase activity, reduction in ability to refold proteins and changes to interaction affinity with specific co-chaperones and protein substrates. Our findings relate specific structural changes in Hsp70 to specific changes in functional properties that underpin important phenotypic changes in vivo. A thorough understanding of the molecular mechanisms of Hsp70 regulation and how specific modifications result in phenotypic change is essential for the development of new drugs targeting Hsp70 for therapeutic purposes. The online version of this article (10.1007/s00018-017-2698-3) contains supplementary material, which is available to authorized users.
登录
查看更多内容
表达SSA1，SSA2，SSA3或SSA4的酵母细胞的全局转录本和表型分析是胞质HSP70-SSA伴侣活性的唯一来源。
影响因子：
4.4
作者：
Hasin N;Cusack SA;Ali SS;Fitzpatrick DA;Jones GW
通讯作者：
Jones GW
影响因子：
16
作者：
Kityk, Roman;Kopp, Juergen;Mayer, Matthias P.
通讯作者：
Mayer, Matthias P.
影响因子：
64.5
作者：
Albanèse, V;Yam, AYW;Frydman, J
通讯作者：
Frydman, J
新发现的朊病毒与酿酒酵母中染色质重塑因子 Swi1 相关
影响因子：
30.8
作者：
Du, Zhiqiang;Park, Kyung-Won;Li, Liming
通讯作者：
Li, Liming
影响因子：
10.5
作者：
KAMADA, Y;JUNG, US;LEVIN, DE
通讯作者：
LEVIN, DE