title: Cytoplasmic localization and redox cysteine residue of APE1/Ref-1 are associated with its anti-inflammatory activity in cultured endothelial cells.
abstract: Apurinic/apyrimidinic endonuclease1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in base excision DNA repair and transcriptional regulation of gene expression. APE1/Ref-1 is mainly localized in the nucleus, but cytoplasmic localization has also been reported. However, the functional role of cytoplasmic APE1/Ref-1 and its redox cysteine residue are still unknown. We investigated the role of cytoplasmic APE1/Ref-1 on tumor necrosis factor-α (TNF-α)-induced vascular cell adhesion molecule-1 (VCAM-1) expressions in endothelial cells. Endogenous APE1/Ref-1 was mainly observed in the nucleus, however, cytoplasmic APE1/Ref-1 was increased by TNF-α. Cytoplasmic APE1/Ref-1 expression was not blunted by cycloheximide, a protein synthesis inhibitor, suggesting cytoplasmic translocation of APE1/Ref-1. Transfection of an N-terminus deletion mutant APE1/Ref-1(29-318) inhibited TNF-α-induced VCAM-1 expression, indicating an anti-inflammatory role for APE1/Ref-1 in the cytoplasm. In contrast, redox mutant of APE1/Ref-1 (C65A/C93A) transfection led to increased TNF-α-induced VCAM-1 expression. Our findings suggest cytoplasmic APE1/Ref-1 localization and redox cysteine residues of APE1/Ref-1 are associated with its anti-inflammatory activity in endothelial cells.
authors.affiliation: Department of Physiology, School of Medicine, Chungnam National University, Daejeon, 301-747, Korea.
authors.forename: Myoung Soo
authors.initials: MS
authors.lastname: Park
authors.forename: Cuk-Seong
authors.initials: CS
authors.lastname: Kim
authors.forename: Hee Kyoung
authors.initials: HK
authors.lastname: Joo
authors.forename: Yu Ran
authors.initials: YR
authors.lastname: Lee
authors.forename: Gun
authors.initials: G
authors.lastname: Kang
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Sunga
authors.initials: S
authors.lastname: Choi
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Lee
authors.forename: Jin Bong
authors.initials: JB
authors.lastname: Park
authors.forename: Byeong Hwa
authors.initials: BH
authors.lastname: Jeon
mesh_terms: D000893:Anti-Inflammatory Agents / Q000378:metabolism*; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D003545:Cysteine / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D009154:Mutation; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
chemical_list: D000893:Anti-Inflammatory Agents; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D003513:Cycloheximide; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D003545:Cysteine