title: Identification of a redox-modulatory interaction between selenoprotein W and 14-3-3 protein.
abstract: Selenoprotein W (SelW) contains a selenocysteine (Sec, U) in a conserved CXXU motif corresponding to the CXXC redox motif of thioredoxin, suggesting a putative redox function of SelW. We have previously reported that the binding of 14-3-3 protein to its target proteins, including CDC25B, Rictor and TAZ, is inhibited by the interaction of 14-3-3 protein with SelW. However, the binding mechanism is unclear. In this study, we sought to determine the binding site of SelW to understand the regulatory mechanism of the interaction between SelW and 14-3-3 and its biological effects. Phosphorylated Ser(pS) or Thr(pT) residues in RSXpSXP or RXXXp(S/T)XP motifs are well-known common 14-3-3-binding sites, but Thr41, Ser59, and T69 of SelW, which are computationally predicted to serve are phosphorylation sites, were neither phosphorylation sites nor sites involved in the interaction. A mutant SelW in which Sec13 is changed to Ser (U13S) was unable to interact with 14-3-3 protein and thus did not inhibit the interaction of 14-3-3 to other target proteins. However, other Cys mutants of SelW(C10S, C33S and C37S) normally interacted with 14-3-3 protein. The interaction of SelW to 14-3-3 protein was enhanced by diamide or H2O2 and decreased by dithiothreitol (DTT). Taken together, these findings demonstrate that the Sec of SelW is involved in its interaction with 14-3-3 protein and that this interaction is increased under oxidative stress conditions. Thus, SelW may have a regulatory function in redox cell signaling by interacting with 14-3-3 protein.
authors.affiliation: Laboratory of Cellular and Molecular Biochemistry, Division of Life Sciences, Korea University, 1, 5-Ka, Anam-Dong, Sungbuk-Ku, Seoul 136-701, Republic of Korea.
authors.forename: Yeong Ha
authors.initials: YH
authors.lastname: Jeon
authors.affiliation: Laboratory of Cellular and Molecular Biochemistry, Division of Life Sciences, Korea University, 1, 5-Ka, Anam-Dong, Sungbuk-Ku, Seoul 136-701, Republic of Korea.
authors.forename: Kwan Young
authors.initials: KY
authors.lastname: Ko
authors.affiliation: Laboratory of Cellular and Molecular Biochemistry, Division of Life Sciences, Korea University, 1, 5-Ka, Anam-Dong, Sungbuk-Ku, Seoul 136-701, Republic of Korea.
authors.forename: Jea Hwang
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Laboratory of Cellular and Molecular Biochemistry, Division of Life Sciences, Korea University, 1, 5-Ka, Anam-Dong, Sungbuk-Ku, Seoul 136-701, Republic of Korea.
authors.forename: Ki Jun
authors.initials: KJ
authors.lastname: Park
authors.affiliation: Laboratory of Cellular and Molecular Biochemistry, Division of Life Sciences, Korea University, 1, 5-Ka, Anam-Dong, Sungbuk-Ku, Seoul 136-701, Republic of Korea.
authors.forename: Jun Ki
authors.initials: JK
authors.lastname: Jang
authors.affiliation: Laboratory of Cellular and Molecular Biochemistry, Division of Life Sciences, Korea University, 1, 5-Ka, Anam-Dong, Sungbuk-Ku, Seoul 136-701, Republic of Korea. Electronic address: ickkim@korea.ac.kr.
authors.forename: Ick Young
authors.initials: IY
authors.lastname: Kim
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism*; D020816:Amino Acid Motifs; D004229:Dithiothreitol / Q000494:pharmacology; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D061986:MCF-7 Cells; D020125:Mutation, Missense; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D051151:Selenoprotein W / Q000235:genetics / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; C495240:SELENOW protein, human; D051151:Selenoprotein W; D006861:Hydrogen Peroxide; D004229:Dithiothreitol
keywords: 14-3-3; SelW; Selenocysteine; Selenoproteins