Structure-function studies on a key signaling module from interleukin 17 receptor

描述（由申请人提供）：白细胞介素17（IL 17）在介导炎症和自身免疫性疾病中起关键作用。一个独特的细胞内信号结构域被称为'SEFIR'被确定在所有的IL 17受体（IL 17 Rs）和衔接蛋白，核因子？B（NF-？B）活化剂1（Act 1）。IL 17信号传导的关键步骤是通过SEFIR介导的缔合将Act 1募集至IL 17 R。作为所有IL 17 R中最大的，IL 17 RA是参与基本上所有IL 17信号传导的关键受体，并且需要由SEFIR和短侧翼C末端延伸组成的独特结构模块（SEFEX）。SEFEX介导的IL 17 RA信号传导的结构和机制尚不清楚。本研究旨在提供IL 17 RA SEFEX结构域的分子细节，揭示SEFEX募集Act 1参与IL 17 RA细胞内信号转导的分子机制。 目标1. IL 17 RA的SEFEX结构域的结构和功能研究。假设：IL 17 RA的细胞内信号传导模块在所有IL 17受体中是独特的，并且含有SEFIR和约100 a.a.与其他IL 17 R和Act 1相比，IL 17 RA SEFIR结构域本身采用独特的结构。I）我们将确定IL 17 RA-SEFEX的晶体结构。II）我们将绘制IL 17 RA SEFEX上的功能残基，这些残基对于与Act 1和IL 17刺激的信号传导的相互作用至关重要。我们将使用诱变、CO-IP、表面等离子体共振和基于细胞的IL 17信号传导测定。目标二。通过结构和功能研究确定IL 17 RA招募Act 1的机制。假设：阻碍？SEFIR结构域中的C是参与异型SEFIR-SEFIR相互作用的保守结构基序。因此，肽来自？Act 1、IL 17 RB或IL 17 RA的C螺旋将抑制IL 17/IL 25信号传导。I）我们将通过结构生物学确定IL 17 RA募集Act 1的分子机制。II）我们将开发用于抑制IL 17信号传导的细胞渗透性抑制肽。这些研究为发现调节IL 17和IL 25信号传导的新方法提供了机会。我们的目标是详细表征来自IL 17 RA的独特信号传导结构域，其是几乎所有IL 17配体信号传导的最常见的共享受体。预期的结果将提供详细的结构信息，为推进我们对IL 17受体信号转导的基本原理的理解。我们的研究将为设计选择性抑制剂提供一个平台， 可进一步开发为针对许多炎症和自身免疫性疾病的新疗法。

DESCRIPTION (provided by applicant): Interleukin 17 (IL17) plays a key role in mediating inflammatory and autoimmune diseases. A unique intracellular signaling domain termed 'SEFIR' was identified within all IL17 receptors (IL17Rs) and the adaptor protein, nuclear factor ?B (NF-?B) activator 1 (Act1). A key step in IL17 signaling is the recruitment of Act1 to IL17Rs via SEFIR mediated associations. As the largest among all IL17Rs, IL17RA is a key receptor involved in essentially all IL17 signaling and requires a unique structural module (SEFEX) that is composed of both SEFIR and a short flanking C-terminal extension. The structure and mechanism of SEFEX-mediated IL17RA signaling are not known. In this proposal, we aim for providing molecular details of SEFEX domain from IL17RA, and revealing the molecular principles by which SEFEX recruits Act1 for IL17RA intracellular signaling. Aim 1. Structural and functional studies on the SEFEX domain of IL17RA. Hypothesis: The intracellular signaling module of IL17RA is unique among all IL17 receptors, and contains the SEFIR and a C-terminal flanking fragment of about 100 a.a. The IL17RA SEFIR domain itself adopts a unique structure, compared to that from other IL17Rs and Act1. I) We will determine the crystal structure of IL17RA-SEFEX. II) We will map the functional residues on IL17RA SEFEX that are critical for interaction with Act1 and IL17-stimulated signaling. We will use mutagenesis, CO-IP, surface plasmon resonance, and cell-based IL17 signaling assays. Aim 2. Determine the mechanism by which IL17RA recruits Act1 by structural and functional studies. Hypothesis: Helix ?C in the SEFIR domains is a conserved structural motif involved in heterotypic SEFIR- SEFIR interactions. Therefore peptides derived from the ?C helix of Act1, IL17RB or IL17RA will be inhibitory for IL17/IL25 signaling. I) We will determine the molecular mechanism by which IL17RA recruits Act1 by structural biology. II) We will develop cell-permeable inhibitory peptides for inhibition of IL17 signaling. These studies offer an opportunity for uncovering novel approaches for modulating IL17 and IL25 signaling. Our objectives are the detailed characterizations of the unique signaling domain from IL17RA, which is the most commonly shared receptor for nearly all IL17 ligands signaling. The expected results will provide detailed structural information for advancing our understanding on the fundamental principles of IL17 receptor signaling. Our studies will provide a platform for designing selective inhibitors that may be further developed into new therapeutics against a number of inflammatory and autoimmune diseases.