Novel Roles of the Non-catalytic Elements of Yeast Protein-disulfide Isomerase in Its Interplay with Endoplasmic Reticulum Oxidoreductin 1
Novel Roles of the Non-catalytic Elements of Yeast Protein-disulfide Isomerase in Its Interplay with Endoplasmic Reticulum Oxidoreductin 1
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酵母蛋白二硫键异构酶非催化元件在其与内质网氧化还原素相互作用中的新作用1。
DOI：
10.1074/jbc.m115.694257
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发表时间：
2016
影响因子：
4.8
通讯作者：
Wang Lei
中科院分区：
文献类型：
--
作者：
Niu Yingbo;Zhang Lihui;Yu Jiaojiao;Wang Chih-chen;Wang Lei
真核细胞内质网 (ER) 中二硫键的形成由巯基氧化酶、ER 氧化还原素 1 (Ero1) 和蛋白质二硫键异构酶 (PDI) 催化。 PDI被Ero1氧化，不断向底物引入二硫化物，并通过操纵Ero1的调节性二硫化物反馈调节Ero1活性。在这项研究中，我们发现酵母Ero1p即使在其调节二硫键完整的情况下也具有酶活性，并且通过还原调节二硫键进一步激活Ero1p需要还原Pdi1p中的非催化Cys90-Cys97二硫键。 Pdi1pb' 域中的主要客户端结合位点不仅对于功能性 Ero1p-Pdi1p 二硫键中继是必需的，而且对于 Ero1p 的激活也是必需的。我们还通过互补激活测定证明，Ero1p 中的调节二硫键比人类 Ero1α 中的调节二硫键稳定得多。这些关于酵母 Ero1p-Pdi1p 相互作用的新发现揭示了与我们之前确定的人类 Ero1α-PDI 相互作用模式的显着差异，并为真核氧化蛋白折叠途径的进化提供了见解。
The formation of disulfide bonds in the endoplasmic reticulum (ER) of eukaryotic cells is catalyzed by the sulfhydryl oxidase, ER oxidoreductin 1 (Ero1), and protein-disulfide isomerase (PDI). PDI is oxidized by Ero1 to continuously introduce disulfides into substrates, and feedback regulates Ero1 activity by manipulating the regulatory disulfides of Ero1. In this study we find that yeast Ero1p is enzymatically active even with its regulatory disulfides intact, and further activation of Ero1p by reduction of the regulatory disulfides requires the reduction of non-catalytic Cys90-Cys97disulfide in Pdi1p. The principal client-binding site in the Pdi1pb′ domain is necessary not only for the functional Ero1p-Pdi1p disulfide relay but also for the activation of Ero1p. We also demonstrate by complementary activation assays that the regulatory disulfides in Ero1p are much more stable than those in human Ero1α. These new findings on yeast Ero1p-Pdi1p interplay reveal significant differences from our previously identified mode of human Ero1α-PDI interplay and provide insights into the evolution of the eukaryotic oxidative protein folding pathway.