TOXI 11 |
| S-nitrosylation, the selective modification of cysteine residues in proteins to form S-nitrosocysteine, is a major emerging mechanism by which nitric oxide acts as a signaling molecule. We employed a proteomic approach using selective peptide capturing and site-specific adduct mapping to identify the targets of S-nitrosylation in human aortic smooth muscle cells upon exposure to S-nitrosocysteine and propylamine propylamine NONOate. This strategy identified 20 unique S-nitrosocysteine-containing peptides belonging to 18 proteins including cytoskeletal proteins, chaperones, proteins of the translational machinery, vesicular transport, and signaling. Sequence analysis of the S-nitrosocysteine-containing peptides revealed the presence of acid-base motifs, as well as hydrophobic motifs surrounding the identified cysteine residues. High-resolution immunogold electron microscopy supported the cellular localization of several of these proteins. Interestingly, seven of the 18 proteins identified are localized within the ER/Golgi complex, suggesting a role for S-nitrosylation in membrane trafficking and ER stress response in vascular smooth muscle. |
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Protein Modification by Electrophiles
2:00 PM-4:10 PM, Sunday, 10 September 2006 Moscone Center -- Room 308, Oral
Division of Chemical Toxicology |