Nitration of PECAM-1 ITIM tyrosines abrogates phosphorylation and SHP-2 binding.
Platelet-endothelial cell adhesion molecule-1 (PECAM-1) is a cell adhesion molecule with a cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM) that, when phosphorylated, binds Src homology 2 domain-containing protein-tyrosine phosphatase (SHP-2). PECAM-1 is expressed at endothelial cell junctions where exposure to inflammatory intermediates may result in post-translational amino acid modifications that affect protein structure and function. Reactive nitrogen species (RNS), which are produced at sites of inflammation, nitrate tyrosine residues, and several proteins modified by tyrosine nitration have been found in diseased tissue. We show here that the RNS, peroxynitrite, induced nitration of both full-length cellular PECAM-1 and a purified recombinant PECAM-1 cytoplasmic domain. Mass spectrometric analysis of tryptic fragments revealed quantitative nitration of ITIM tyrosine 686. A synthetic peptide containing 3-nitrotyrosine at position 686 could not be phosphorylated nor bind SHP-2. These data suggest that ITIM tyrosine nitration may represent a mechanism for modulating phosphotyrosine-dependent signal transduction pathways.
Newman
Debra K
DK
Blood Research Institute, The Blood Center of Southeastern Wisconsin, 53226, Milwaukee, WI, USA. dknewman@bcsew.edu
Hoffman
Sara
S
Kotamraju
Srigiridhar
S
Zhao
Tieming
T
Wakim
Bassam
B
Kalyanaraman
Balaraman
B
Newman
Peter J
PJ
D000595:Amino Acid Sequence; D002460:Cell Line; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D019169:Jurkat Cells; D008969:Molecular Sequence Data; D030421:Peroxynitrous Acid / Q000494:pharmacology; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000737:chemistry; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism*
D047908:Intracellular Signaling Peptides and Proteins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011971:Receptors, Immunologic; D030421:Peroxynitrous Acid; D019000:Phosphotyrosine; C002744:3-nitrotyrosine; D014443:Tyrosine; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases