title: Apurinic/apyrimidinic endonuclease 1 inhibits protein kinase C-mediated p66shc phosphorylation and vasoconstriction.
abstract: OBJECTIVE
  Phosphorylation of the adaptor protein p66shc is essential for p66shc-mediated oxidative stress. We investigated the role of the reducing protein/DNA repair enzyme apurinic/apyrimidinic endonuclease1 (APE1) in modulating protein kinase CβII (PKCβII)-mediated p66shc phosphorylation in cultured endothelial cells and PKC-mediated vasoconstriction of arteries.
  
  
  RESULTS
  Oxidized low-density lipoprotein (oxLDL)induced p66shc phosphorylation at serine 36 residue and PKCβII phosphorylation in mouse endothelial cells. Adenoviral overexpression of APE1 resulted in reduction of oxLDL-induced p66shc and PKCβII phosphorylation. Phorbol 12-myristate 13-acetate (PMA), which stimulates PKCs, induced p66shc phosphorylation and this was inhibited by a selective PKCβII inhibitor. Adenoviral overexpression of PKCβII also increased p66shc phosphorylation. Overexpression of APE1 suppressed PMA-induced p66shc phosphorylation. Moreover, PMA-induced p66shc phosphorylation was augmented in cells in which APE1 was knocked down. PMA increased cytoplasmic APE1 expression, compared with the basal condition, suggesting the role of cytoplasmic APE1 against p66shc phosphorylation. Finally, vasoconstriction induced by phorbol-12,13, dibutylrate, another PKC agonist, was partially inhibited by transduction of Tat-APE1 into arteries.
  
  
  CONCLUSIONS
  APE1 suppresses oxLDL-induced p66shc activation in endothelial cells by inhibiting PKCβII-mediated serine phosphorylation of p66shc, and mitigates vasoconstriction induced by activation of PKC.
authors.affiliation: Infection Signaling Network Research Center, Research Institute of Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, 6 Munhwa-dong, Jung-gu, Daejeon, Korea.
authors.forename: Sang Ki
authors.initials: SK
authors.lastname: Lee
authors.forename: Jae In
authors.initials: JI
authors.lastname: Chung
authors.forename: Myoung Soo
authors.initials: MS
authors.lastname: Park
authors.forename: Hee Kyoung
authors.initials: HK
authors.lastname: Joo
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Lee
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Cho
authors.forename: Jin Bong
authors.initials: JB
authors.lastname: Park
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Ryoo
authors.forename: Kaikobad
authors.initials: K
authors.lastname: Irani
authors.forename: Byeong Hwa
authors.initials: BH
authors.lastname: Jeon
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology*; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000494:pharmacology; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism; D051379:Mice; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D064546:Protein Kinase C beta; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000378:metabolism; D055765:Shc Signaling Adaptor Proteins / Q000378:metabolism*; D015398:Signal Transduction; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D013997:Time Factors; D014161:Transduction, Genetic; D014162:Transfection; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D020536:Enzyme Activators; D008077:Lipoproteins, LDL; D047428:Protein Kinase Inhibitors; D011994:Recombinant Proteins; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; C099252:oxidized low density lipoprotein; D011493:Protein Kinase C; D064546:Protein Kinase C beta; C085108:APEX1 protein, human; C486216:Apex1 protein, mouse; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase