RT Journal Article T1 S-Nitrosylation of the Death Receptor Fas Promotes Fas Ligand–Mediated Apoptosis in Cancer Cells A1 Leon-Bollotte, Lissbeth A1 Subramaniam, Selvakumar A1 Cauvard, Olivier A1 Plenchette–Colas, Stéphanie A1 Paul, Catherine A1 Godard, Cindy A1 Martínez Ruiz, Antonio A1 Legembre, Patrick A1 Jeannin, Jean–François A1 Bettaieb, Ali AB BACKGROUND & AIMS: Fas belongs to the family of tumor necrosis factor receptors which induce apoptosis. Many cancer cells express Fas but do not undergo Fasmediated 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 a nd 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 monitoredaccording 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, NOmediated translocation of Fas to lipid rafts was affectedand 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. SN 0016-5085 YR 2011 FD 2011-06 LK https://hdl.handle.net/20.500.14352/103020 UL https://hdl.handle.net/20.500.14352/103020 LA eng DS Docta Complutense RD 9 abr 2025