This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Inducible nitric-oxide synthase (iNOS) produces biologically stressful levels of nitric oxide (NO) as a potent mediator of cellular cytotoxicity or signaling. Yet, how this nitrosative stress affects iNOS function in vivo is poorly understood. Here we define two specific non-heme iNOS nitrosation sites discovered by combining UV-visible spectroscopy, chemiluminescence, mass spectrometry, and x-ray crystallography. We detected auto-S-nitrosylation during enzymatic turnover by using chemiluminescence. Selective S-nitrosylation of the ZnS(4) site, which bridges the dimer interface, promoted a dimer-destabilizing order-to-disorder transition. The nitrosated iNOS crystal structure revealed an unexpected N-NO modification on the pterin cofactor. Furthermore, the structurally defined N-NO moiety is solvent-exposed and available to transfer NO to a partner. We investigated glutathione (GSH) as a potential transnitrosation partner because the intracellular GSH concentration is high and NOS can form S-nitrosoglutathione. Our computational results predicted a GSH binding site adjacent to the N-NO-pterin. Moreover, we detected GSH binding to iNOS with saturation transfer difference NMR spectroscopy. Collectively, these observations resolve previous paradoxes regarding this uncommon pterin cofactor in NOS and suggest means for regulating iNOS activity via N-NO-pterin and S-NO-Cys modifications. The iNOS self-nitrosation characterized here appears appropriate to help control NO production in response to cellular conditions.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
Biotechnology Resource Grants (P41)
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University of Washington
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Shan, Chun-Min; Wang, Jiyong; Xu, Ke et al. (2016) A histone H3K9M mutation traps histone methyltransferase Clr4 to prevent heterochromatin spreading. Elife 5:
Kim, Tae Kwon; Tirloni, Lucas; Pinto, Antônio F M et al. (2016) Ixodes scapularis Tick Saliva Proteins Sequentially Secreted Every 24 h during Blood Feeding. PLoS Negl Trop Dis 10:e0004323
McBride, Ryan; Paulson, James C; de Vries, Robert P (2016) A Miniaturized Glycan Microarray Assay for Assessing Avidity and Specificity of Influenza A Virus Hemagglutinins. J Vis Exp :
McClatchy, D B; Savas, J N; Martínez-Bartolomé, S et al. (2016) Global quantitative analysis of phosphorylation underlying phencyclidine signaling and sensorimotor gating in the prefrontal cortex. Mol Psychiatry 21:205-15
Wang, Jiyong; Cohen, Allison L; Letian, Anudari et al. (2016) The proper connection between shelterin components is required for telomeric heterochromatin assembly. Genes Dev 30:827-39
Di Maggio, Lucía Sánchez; Tirloni, Lucas; Pinto, Antonio F M et al. (2016) Across intra-mammalian stages of the liver f luke Fasciola hepatica: a proteomic study. Sci Rep 6:32796
Homer, Christina M; Summers, Diana K; Goranov, Alexi I et al. (2016) Intracellular Action of a Secreted Peptide Required for Fungal Virulence. Cell Host Microbe 19:849-64
Silva, Erica; Betleja, Ewelina; John, Emily et al. (2016) Ccdc11 is a novel centriolar satellite protein essential for ciliogenesis and establishment of left-right asymmetry. Mol Biol Cell 27:48-63
Tang, Wen; Tu, Shikui; Lee, Heng-Chi et al. (2016) The RNase PARN-1 Trims piRNA 3' Ends to Promote Transcriptome Surveillance in C. elegans. Cell 164:974-84
Carvalho, Paulo C; Lima, Diogo B; Leprevost, Felipe V et al. (2016) Integrated analysis of shotgun proteomic data with PatternLab for proteomics 4.0. Nat Protoc 11:102-17

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