title: Novel Roles of the Non-catalytic Elements of Yeast Protein-disulfide Isomerase in Its Interplay with Endoplasmic Reticulum Oxidoreductin 1.
abstract: 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 Cys(90)-Cys(97)disulfide 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.
authors: From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 and the University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Yingbo
authors: Y
authors: Niu
authors: From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 and the University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Lihui
authors: L
authors: Zhang
authors: From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 and the University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Jiaojiao
authors: J
authors: Yu
authors: From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 and chihwang@sun5.ibp.ac.cn.
authors: Chih-Chen
authors: CC
authors: Wang
authors: From the National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 and wanglei@moon.ibp.ac.cn.
authors: Lei
authors: L
authors: Wang
mesh_terms: D004220:Disulfides / Q000737:chemistry / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010084:Oxidation-Reduction; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry / Q000378:metabolism*; D019704:Protein Disulfide-Isomerases / Q000737:chemistry / Q000378:metabolism*; D060066:Protein Interaction Maps; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004220:Disulfides; D006023:Glycoproteins; C080576:PDI1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C113186:ERO1 protein, S cerevisiae; D019704:Protein Disulfide-Isomerases
keywords: Ero1; disulfide; endoplasmic reticulum (ER); oxidative protein folding; protein-disulfide isomerase; protein-protein interaction; redox regulation; regulatory disulfide