Translational control of inflammatory gene expression

项目2的长期目标是阐明调控基因的转录后机制 在血管系统炎症中的表达。干扰素-v是单核细胞/巨噬细胞的经典激活剂。 噬菌体，并诱导炎性生长因子、蛋白酶、趋化因子和基因的快速转录。 激进物种的破坏者。如果不加以控制，这个过程就会变成慢性的单核/巨噬细胞产物 积聚、损害宿主组织，并导致慢性血管疾病，如动脉粥样硬化。 炎症的终止不是在最初的侮辱消除之后开始的一个被动的过程；在 相反，内在机制会主动限制潜在损伤蛋白的表达。最近，调查- ORS已经认识到转录后过程在限制或消除炎症方面的重要作用。 我们发现了一种新的翻译控制途径，它作为一种内源性调节因子 炎症反应。在髓系细胞中，干扰素-γ可诱导异四聚体--干扰素-γ的组装。 激活的翻译抑制物(GATIT)复合体，它结合3‘非翻译区的RNA元件 某些促炎靶基因的表达，例如血管内皮生长因子-A，并抑制其 翻译。在初步研究中，我们发现一种步态蛋白，谷氨酰-脯氨基-tRNA合成酶(Eprs)， 是步态系统的核心，因为它负责靶基因的识别，其功能是调节。 通过其他3种步态蛋白的磷酸化和结合而延迟。我们认为Eprs不是一种惰性的蛋白质- 捆绑脚手架，而是一个受刺激诱导的调节步态的动态系统 复杂的装配和功能。基于这些结果，我们提出了以下假设：磷酸化- 依赖于干扰素的蛋白激酶对Eprs的作用导致Eprs的构象变化，从而调节组装 步态复合体的表达，沉默炎性基因靶标的翻译，并有助于解决。 治疗慢性炎症。我们将通过追求三个具体目标来检验这一假设。在目标1中，我们将 确定步态复合体组装和步态元素结合所需的EPRS域。在《目标2》中，我们 将决定EPRS磷酸化在步态复合体组装和功能中的作用。在《目标3》中，我们将 研究Eprs和步态复合体的体内抗炎作用。 相关性(请参阅说明)： 我们的研究将阐明一条调节巨噬细胞炎性蛋白合成的新途径，以及 在动脉粥样硬化等血管疾病的发展过程中起着重要作用。正在调查的路径 有助于限制和消除慢性炎症，慢性炎症是疾病进展的重要原因。 加深对炎症性“停止”途径的了解很重要，因为这些途径中的缺陷可能会导致 血管疾病，而且因为该途径本身可能为开发新的抗肿瘤药物提供替代靶点 炎症疗法。

The long-term goal of Project 2 is to elucidate the post-transcriptional mechanisms that modulate gene expression in inflammation of the vasculature. Interferon (IFN)-v is the classic activator of monocyte/macro- phages, and it induces rapid transcription of inflammatory growth factors, proteases, chemokines, and gen- erators of radical species. If unregulated, this process becomes chronic and monocyte/macrophage products accumulate, damage host tissue, and contribute to chronic disorders of blood vessels, e.g., atherosclerosis. The termination of inflammation is not a passive process that begins after elimination of the initial insult; in contrast, intrinsic mechanisms actively limit expression of potentially injurious proteins. Recently, investigat- ors have recognized the important role of post-transcriptional processes in limiting or resolving inflammation. We have discovered a novel translational control pathway that acts as an endogenous regulator of the inflammatory response. In myeloid cells, IFN-y induces assembly of the heterotetrameric, IFN-Gamma- Activated inhibitor of Translation (GAIT) complex, which binds an RNA element in the 3'untranslated region of certain pro-inflammatory target mRNAs, e.g., vascular endothelial growth factor-A, and inhibits their translation. In Preliminary Studies we show that one GAIT protein, glutamyl-prolyl-tRNA synthetase (EPRS), is central to the GAIT system because it is responsible for target mRNA recognition, and its function is regu- lated by phosphorylation and binding of the other 3 GAIT proteins. We suggest EPRS is not an inert, protein- binding scaffold, but rather a dynamic system subject to stimulus-inducible modifications that regulate GAIT complex assembly and function. Based on these results, we propose the following hypothesis: Phosphoryl- ation of EPRS by IFN-y-dependent kinases causes conformational changes in EPRS that regulate assembly of the GAIT complex, which silences translation of inflammatory mRNA targets and contributes to the resolu- tion of chronic inflammation. We will test this hypothesis by pursuit of three Specific Aims. In Aim 1 we will determine the EPRS domains required for GAIT complex assembly and GAIT element-binding. In Aim 2 we will determine the role of EPRS phosphorylation in GAIT complex assembly and function. In Aim 3 we will investigate the anti-inflammatory function of EPRS and the GAIT complex in vivo. RELEVANCE (See instructions): Our studies will elucidate a new pathway that regulates the synthesis of inflammatory proteins by macrophages, an important process in the development of vascular diseases such as atherosclerosis. The pathway under investigation contributes to the limitation and resolution of chronic inflammation, an important causative factor in disease progression. A deeper understanding of inflammatory "stop" pathways is important because defects in these pathways can contribute to vascular disorders, and because the pathway itself may present alternative targets for development of novel anti- inflammatory therapeutics.