Specificity and Control of Signaling by S-Nitrosation

描述(申请人提供)：S-亚硝化反应的控制因素未知。此外，S-亚硝化信号的分支几乎是未知的。确定允许细胞在S-亚硝化反应中实现特异性的分子机制(S)是这一提议的重点。一氧化氮(NO)在哺乳动物的血管扩张、神经信号转导和免疫等生理过程中发挥着不可或缺的作用。NO通过多条途径影响细胞生理。研究得最好的途径是通过与酶--可溶性鸟苷环化酶(SGC)结合。当只考虑sgc作为目标时，所描述的NO的行为不能完全解释。S-亚硝化是一种sGC非依赖性信号转导途径，涉及半胱氨酸对蛋白质的翻译后修饰。在许多情况下，半胱氨酸的修饰会改变蛋白质的功能。与此类似的过程几乎完全是一种受调控的细胞事件，生物机械处于严格控制之下。体外研究表明，当NO与蛋白质反应时，许多半胱氨酸硫醇被修饰。然而，在细胞环境中，如果没有添加NO，而是由细胞本身产生，则永远不会发生多次修饰。此外，NO的合成浓度非常低，因此如果没有适当的控制机制，蛋白质修饰将非常低效。对这种差异最合理的解释是，体外实验缺乏赋予S亚硝化反应特异性的细胞成分。在实验方面，该项目将尝试使用各种先进的工具来鉴定这些成分，如：定制的亲和探针、电感耦合等离子体光谱、荧光光谱以及最近开发的S-亚硝化特异性生化分析。一氧化氮(NO)介导血管松弛、心肌功能的复杂方面、所有主要器官的灌流和功能、脑内突触的可塑性、血小板聚集、皮肤功能和许多其他生理过程。鉴于NO在人类生物学中的作用，完全了解其信号转导的分子细节将明显应用于理解和治疗广泛的疾病，如高血压和心血管疾病。这项研究可以导致更有效的治疗方法的开发，并有可能降低医疗保健成本。

DESCRIPTION (provided by applicant): The controls governing S-nitrosation are unknown. In addition, the ramifications of S-nitrosation signaling are virtually unknown. Determining the molecular mechanism(s) that permits cells to achieve specificity in S-nitrosation reactions is the focus of this proposal. Nitric oxide (NO) plays integral roles in mammalian physiology including vasodilation, neuronal signaling, and immunity. NO affects cellular physiology by multiple pathways. The best studied pathway is through binding to the enzyme, soluble guanylate cyclase (sGC). The actions of NO that have been described cannot be completely accounted for when only considering sGC as a target. S-Nitrosation is one type of sGC-independent signaling and involves the post-translational modification of cysteine on proteins. In many cases, modification of a cysteine alters protein function. Processes similar to this are almost exclusively a regulated cellular event with a biological machinery in tight control. In vitro work has shown that when NO reacts with a protein, many cysteine thiols are modified. However, in a cellular context when NO was not added but produced by the cell itself, multiple modifications never occur. Additionally, NO is synthesized at very low concentrations such that without a control mechanism in place, protein modification would be highly inefficient. The most logical explanation for such disparities is that the in vitro experiment lacked the cellular components that confer specificity to the S-nitrosation reaction. Experimentally, this project will attempt to identify these components by using a variety of advanced tools such as: tailored affinity probes, inductively-coupled plasma spectroscopy, fluorescence spectroscopy, and recently developed S-nitrosation specific biochemical assays. Nitric oxide (NO) mediates blood vessel relaxation, complex aspects of myocardial function, perfusion and function of all major organs, synaptic plasticity in the brain, platelet aggregation, skin function, and numerous other physiological processes. Given the role of NO in human biology, a complete understanding of the molecular details involved in its signaling will have clear application to the understanding and treatment of a broad spectrum of diseases, such as hypertension and cardiovascular disease. This research can lead to the development of more effective therapies and, potentially, reduce health care costs.