title: S-nitrosylation of the death receptor fas promotes fas ligand-mediated apoptosis in cancer cells.
abstract: OBJECTIVE
  Fas belongs to the family of tumor necrosis factor receptors which induce apoptosis. Many cancer cells express Fas but do not undergo Fas-mediated apoptosis. Nitric oxide reverses this resistance by increasing levels of Fas at the plasma membrane. We studied the mechanisms by which NO affects Fas function.
  
  
  METHODS
  Colon and mammary cancer cell lines were incubated with the NO donor glyceryl trinitrate or lipid A; S-nitrosylation of Fas was monitored using the biotin switch assay. Fas constructs that contained mutations at cysteine residues that prevent S-nitrosylation were used to investigate the involvement of S-nitrosylation in Fas-mediated cell death. Apoptosis was monitored according to morphologic criteria.
  
  
  RESULTS
  NO induced S-nitrosylation of cysteine residues 199 and 304 in the cytoplasmic part of Fas. In cancer cells that overexpressed wild-type Fas, S-nitrosylation induced Fas recruitment to lipid rafts and sensitized the cells to Fas ligand. In cells that expressed a mutant form of Fas in which cysteine 304 was replaced by valine residue, NO-mediated translocation of Fas to lipid rafts was affected and the death-inducing signal complex and synergistic effect of glyceryl trinitrate-Fas ligand were inhibited significantly. These effects were not observed in cells that expressed Fas with a mutation at cysteine 199.
  
  
  CONCLUSIONS
  We identified post-translational modifications (S-nitrosylation of cysteine residues 199 and 304) in the cytoplasmic domain of Fas. S-nitrosylation at cysteine 304 promotes redistribution of Fas to lipid rafts, formation of the death-inducing signal complex, and induction of cell death.
authors.affiliation: Ecole Pratique des Hautes Etudes, Tumor Immunology and Immunotherapy Laboratory, Dijon, France.
authors.forename: Lissbeth
authors.initials: L
authors.lastname: Leon-Bollotte
authors.forename: Selvakumar
authors.initials: S
authors.lastname: Subramaniam
authors.forename: Olivier
authors.initials: O
authors.lastname: Cauvard
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Plenchette-Colas
authors.forename: Catherine
authors.initials: C
authors.lastname: Paul
authors.forename: Cindy
authors.initials: C
authors.lastname: Godard
authors.forename: Antonio
authors.initials: A
authors.lastname: Martinez-Ruiz
authors.forename: Patrick
authors.initials: P
authors.lastname: Legembre
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Jeannin
authors.forename: Ali
authors.initials: A
authors.lastname: Bettaieb
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D019921:Biotinylation; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D003545:Cysteine; D053222:Fas Ligand Protein / Q000378:metabolism*; D005260:Female; D006801:Humans; D008050:Lipid A / Q000494:pharmacology; D008325:Mammary Neoplasms, Experimental / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D021962:Membrane Microdomains / Q000378:metabolism; D051379:Mice; D009154:Mutation; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D005996:Nitroglycerin / Q000494:pharmacology; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D021381:Protein Transport; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism*
chemical_list: C491901:FAS protein, human; D053222:Fas Ligand Protein; C491899:Fas protein, mouse; D008050:Lipid A; D020030:Nitric Oxide Donors; D019014:fas Receptor; D009569:Nitric Oxide; D005996:Nitroglycerin; D003545:Cysteine