title: Inhibition of the functional interplay between endoplasmic reticulum (ER) oxidoreduclin-1α (Ero1α) and protein-disulfide isomerase (PDI) by the endocrine disruptor bisphenol A.
abstract: Bisphenol A (BPA) is an endocrine disruptor that may have adverse effects on human health. We recently isolated protein-disulfide isomerase (PDI) as a BPA-binding protein from rat brain homogenates and found that BPA markedly inhibited PDI activity. To elucidate mechanisms of this inhibition, detailed structural, biophysical, and functional analyses of PDI were performed in the presence of BPA. BPA binding to PDI induced significant rearrangement of the N-terminal thioredoxin domain of PDI, resulting in more compact overall structure. This conformational change led to closure of the substrate-binding pocket in b' domain, preventing PDI from binding to unfolded proteins. The b' domain also plays an essential role in the interplay between PDI and ER oxidoreduclin 1α (Ero1α), a flavoenzyme responsible for reoxidation of PDI. We show that BPA inhibited Ero1α-catalyzed PDI oxidation presumably by inhibiting the interaction between the b' domain of PDI and Ero1α; the phenol groups of BPA probably compete with a highly conserved tryptophan residue, located in the protruding β-hairpin of Ero1α, for binding to PDI. Consistently, BPA slowed down the reoxidation of PDI and caused the reduction of PDI in HeLa cells, indicating that BPA has a great impact on the redox homeostasis of PDI within cells. However, BPA had no effect on the interaction between PDI and peroxiredoxin-4 (Prx4), another PDI family oxidase, suggesting that the interaction between Prx4 and PDI is different from that of Ero1α and PDI. These results indicate that BPA, a widely distributed and potentially harmful chemical, inhibits Ero1-PDI-mediated disulfide bond formation.
authors.affiliation: School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan,; Division of Protein Chemistry, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan,; RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan,; School Faculty of Science and Engineering, Kinki University, Kowakae 3-4-1, Higashi-Osaka, Osaka 577-8502, Japan,; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan. Electronic address: okmasaki@mail.tagen.tohoku.ac.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Okumura
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kadokura
authors.affiliation: School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Hashimoto
authors.affiliation: RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Yutani
authors.affiliation: School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan,; RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan,; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Kanemura
authors.affiliation: RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Hikima
authors.affiliation: School Faculty of Science and Engineering, Kinki University, Kowakae 3-4-1, Higashi-Osaka, Osaka 577-8502, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hidaka
authors.affiliation: School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan.
authors.forename: Len
authors.initials: L
authors.lastname: Ito
authors.affiliation: ProCube Business Division, Sysmex Corporation, 1-1-2, Murotani, Nishi-ku, Kobe, Hyogo, 651-2241, Japan, and.
authors.forename: Kohei
authors.initials: K
authors.lastname: Shiba
authors.affiliation: Division of Protein Chemistry, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan,; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Masui
authors.affiliation: School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan,; RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Imai
authors.affiliation: School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Imaoka
authors.affiliation: School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan,; RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan,. Electronic address: hiroshi@kwansei.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamaguchi
authors.affiliation: Division of Protein Chemistry, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan,; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan. Electronic address: kinaba@tagen.tohoku.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Inaba
mesh_terms: D000818:Animals; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism; D010636:Phenols / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051381:Rats; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D004968:Estrogens, Non-Steroidal; D008562:Membrane Glycoproteins; D010088:Oxidoreductases; D054464:Peroxiredoxins; D010636:Phenols; D019704:Protein Disulfide-Isomerases; C485766:Ero1a protein, rat; C405327:ERO1A protein, human; C515980:PRDX4 protein, human; C515982:Prdx4 protein, rat; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Endoplasmic Reticulum (ER); Enzyme Inhibitor; Protein Conformation; Protein Folding; Protein Isomerase