title: Nitric oxide controls nuclear export of APE1/Ref-1 through S-nitrosation of cysteines 93 and 310.
abstract: Apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/Ref-1, abbreviated as APE1) is a molecule with dual functions in DNA repair and redox regulation of transcription factors. Accumulated work has shown that the biological activities of APE1 are sensitive to oxidative stress; however, whether APE1 functions can be regulated by nitrosative stress remains unknown. In this investigation, we found that S-nitrosoglutathion (GSNO), a nitric oxide donor and also an S-nitrosating agent, effectively stimulated nuclear export of APE1 in a CRM1-independent manner. This nuclear-cytoplasmic translocation was dependent on S-nitrosation modification of APE1, as simultaneous mutation of S-nitrosation target sites Cys93 and Cys310 completely abrogated the cytoplasmic redistribution. The translocation process was reversal and specific, as it could be reversed by reductive reagents, but could not be mimicked by H2O2. In structure, the region aa.64-80 and the beta-strand aa.311-316 in proximity to Cys93 and Cys310 were important for GSNO-induced APE1 relocalization. In addition, a defect of importin-mediated nuclear import pathway was found in the NO-insulted cells, and p50 and HDAC2 were identified as APE1 nuclear export inhibitory proteins. Together, this study may provide a novel molecular mechanism, which links nitrosative stress to APE1-associated physiological and pathological processes.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, and Graduate School of the Chinese Academy of Sciences, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Qu
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.forename: Chang
authors.initials: C
authors.lastname: Chen
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000737:chemistry* / Q000378:metabolism*; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases / Q000378:metabolism; D006801:Humans; D028884:Karyopherins / Q000378:metabolism; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D015538:Nitrosation; D017433:Protein Structure, Secondary; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D026422:S-Nitrosoglutathione / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000097606:Exportin 1 Protein
chemical_list: D003545:Cysteine; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases; D028884:Karyopherins; D009569:Nitric Oxide; D020030:Nitric Oxide Donors; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D026422:S-Nitrosoglutathione; D000097606:Exportin 1 Protein; C085108:APEX1 protein, human