Abstract:
Aims: S-nitrosylation of proteins is the main mechanism through which nitric oxide (NO) regulates cellular function and likely represents the archetype redox-based signaling system across aerobic and anaerobic organisms. How NO generated by different nitric oxide synthase (NOS) isoforms leads to specificity of S-nitrosylation remains incompletely understood. This study aimed to identify proteins interacting with, and whose S-nitrosylation is mediated by, human NOS isoforms in the same cellular system, thereby illuminating the contribution of individual NOSs to specificity. Results: Of the hundreds of proteins interacting with each NOS, many were also S-nitrosylated. However, a large proportion of S-nitrosylated proteins (SNO-proteins) did not associate with NOS. Moreover, most NOS interactors and SNO-proteins were unique to each isoform. The amount of NO produced by each NOS isoform was unrelated to the numbers of SNO-proteins. Thus, NOSs promoted S-nitrosylation of largely distinct sets of target proteins. Different signaling pathways were enriched downstream of each NOS. Innovation and Conclusion: The interactomes and SNOomes of individual NOS isoforms were largely distinct. Only a small fraction of SNO-proteins interacted with their respective NOS. Amounts of S-nitrosylation were unrelated to the amount of NO generated by NOSs. These data argue against free diffusion of NO or NOS interactions as being necessary or sufficient for S-nitrosylation and favor roles for additional enzymes and/or regulatory elements in imparting SNO-protein specificity. Antioxid. Redox Signal. 39, 621-634.
摘要:
目的:蛋白质的S-亚硝基化是一氧化氮(NO)调节细胞功能的主要机制,可能代表了有氧和厌氧生物中基于氧化还原的原型信号系统。由不同的一氧化氮合酶(NOS)亚型产生的NO如何导致S-亚硝基化的特异性仍未完全了解。这项研究旨在鉴定与蛋白质相互作用的蛋白质,其S-亚硝基化是由,在同一细胞系统中的人NOS同工型,从而阐明了单个NOS对特异性的贡献。结果:在与每个NOS相互作用的数百种蛋白质中,许多也是S-亚硝基化的。然而,大部分S-亚硝基化蛋白(SNO-蛋白)与NOS不相关.此外,大多数NOS相互作用物和SNO蛋白是每种同工型特有的。每种NOS同工型产生的NO量与SNO蛋白的数量无关。因此,NOSs促进了大量不同的靶蛋白的S-亚硝基化。每个NOS的下游富集了不同的信号通路。创新和结论:各个NOS亚型的间动组和SNOome在很大程度上是不同的。只有一小部分SNO蛋白与各自的NOS相互作用。S-亚硝基化的量与NOSs产生的NO量无关。这些数据认为NO或NOS相互作用的自由扩散对于S-亚硝基化是必需或足够的,并且有利于其他酶和/或调节元件在赋予SNO蛋白特异性中的作用。