Specificity and Control of Signaling by S-Nitrosation

描述（由申请人提供）：S-亚硝化的控制措施未知。此外，S-亚硝化信号的分支实际上是未知的。确定允许细胞在S-亚硝化反应中实现特异性的分子机制是本提案的重点。一氧化氮（NO）在哺乳动物生理学中起着不可或缺的作用，包括血管舒张、神经元信号传导和免疫。NO通过多种途径影响细胞生理。研究得最好的途径是通过与可溶性鸟苷酸环化酶（sGC）结合。当仅考虑sGC作为靶标时，不能完全解释已经描述的NO的作用。S-亚硝化是一种sGC非依赖性信号传导，涉及蛋白质上半胱氨酸的翻译后修饰。在许多情况下，半胱氨酸的修饰改变蛋白质功能。与此类似的过程几乎完全是受生物机制严格控制的受调节细胞事件。体外研究表明，当NO与蛋白质反应时，许多半胱氨酸巯基被修饰。然而，在细胞环境中，当NO不被添加而是由细胞自身产生时，不会发生多种修饰。此外，NO以非常低的浓度合成，使得在没有适当的控制机制的情况下，蛋白质修饰将是非常低效的。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。在实验上，该项目将尝试通过使用各种先进的工具，如：定制的亲和探针，电感耦合等离子体光谱，荧光光谱，和最近开发的S-亚硝化特定的生化分析，以确定这些组件。一氧化氮（NO）介导血管舒张、心肌功能的复杂方面、所有主要器官的灌注和功能、脑中的突触可塑性、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，对其信号传导所涉及的分子细节的完整理解将对理解和治疗广泛的疾病（如高血压和心血管疾病）具有明确的应用。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.