Polypeptide Hormone Receptor Recognition and Activation

多肽激素受体识别和激活

基本信息

批准号：
6919193
负责人：
Kenan Christopher GARCIA
金额：
$ 40万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-07-05 至 2008-06-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Polypeptide hormones engage cell surface signaling receptors to regulate an enormously diverse array of physiological functions. Our body fluid volume and blood pressure, termed volume homeostasis, are regulated, in large part, by a family of secreted natriuretic peptide (NP) hormones and their receptors (NPR), whose signaling is coupled to guanylyl cyclase (GC). In organs such as the heart, kidney, intestine, eye, and vascular system, the interactions of NPs with NPRs serve multiple and coordinate roles in mobilizing water excretion and ion transport. Disregulation of the components of this hypotensive system manifests in pathological conditions such as high blood pressure (hypertension), congestive heart failure, renal failure, and infectious diarrhea. These diverse maladies are linked by an inability to effectively manage fluid volume. In fact, the importance of the NP system as a therapeutic target was validated in 2001 by the introduction of Brain Natriuretic Peptide (BNP) into the clinic (Natrecor(r)), as the first new treatment for congestive heart failure in 15 years. Numerous other indications for NP-targeted therapy exist, most recently in colon cancer and angiogenesis. Our hypothesis is that understanding the molecular basis of NP hormone recognition, and the subsequent intracellular mechanisms of NP receptor activation, are necessary to eventually achieve the most effective modulation of this system. We propose that focused structural, biochemical, and pharmacological studies of the extracellular NP receptor-ligand interactions, in tandem with the intracellular NP receptor signaling modules, will elucidate a complete mechanistic understanding of the allosteric transitions which couple hormone recognition to receptor activation. We will express soluble, recombinant forms of NPR extracellular (ECD) and intracellular (ICD) domains for biochemical characterization of hormone recognition, and guanylyl cyclase activation, respectively. We will determine the three-dimensional structures of the quiescent (unliganded) and active (complexed) ECD and ICD by x-ray crystallography, in order to visualize the receptor-bound conformations of the NP polypeptide hormones, as well as ligand-induced conformational changes in the receptors. We will then utilize these results to design modified, receptor-selective variants of NP hormones with a potential clinical utility. Hence, the ultimate goals of this project are both fundamental and applied. The structural studies will elucidate novel mechanistic paradigms about receptor signaling, which will have direct applications to the therapeutic goal of modulating volume homeostasis in a variety of edematous disorders.

描述（由申请人提供）：多肽激素与细胞表面信号传导受体结合来调节多种多样的生理功能。我们的体液容量和血压（称为容量稳态）在很大程度上受到一系列分泌性利钠肽 (NP) 激素及其受体 (NPR) 的调节，其信号传导与鸟苷酸环化酶 (GC) 耦合。在心脏、肾、肠、眼和血管系统等器官中，NPs 与 NPRs 的相互作用在动员水排泄和离子运输方面发挥着多重协调作用。该低血压系统各组成部分的失调表现为高血压、充血性心力衰竭、肾衰竭和感染性腹泻等病理状况。这些不同的疾病与无法有效管理液体量有关。事实上，2001 年，脑利钠肽 (BNP) 被引入临床 (Natrecor(r))，作为 15 年来第一种治疗充血性心力衰竭的新疗法，证实了 NP 系统作为治疗靶点的重要性。 NP 靶向治疗还存在许多其他适应症，最近的适应症是结肠癌和血管生成。我们的假设是，了解 NP 激素识别的分子基础，以及随后 NP 受体激活的细胞内机制，对于最终实现该系统最有效的调节是必要的。我们建议，对细胞外 NP 受体-配体相互作用进行集中的结构、生化和药理学研究，与细胞内 NP 受体信号传导模块相结合，将阐明对将激素识别与受体激活相结合的变构转变的完整机制理解。我们将表达可溶性重组形式的 NPR 胞外 (ECD) 和胞内 (ICD) 结构域，分别用于激素识别和鸟苷酸环化酶激活的生化表征。我们将通过 X 射线晶体学确定静态（未配体）和活性（复合）ECD 和 ICD 的三维结构，以便可视化 NP 多肽激素的受体结合构象，以及配体诱导的构象。受体的变化。然后，我们将利用这些结果来设计具有潜在临床实用性的修饰的、受体选择性的 NP 激素变体。因此，该项目的最终目标既是基础性的，又是应用性的。结构研究将阐明有关受体信号传导的新机制范例，这将直接应用于调节各种水肿性疾病的容量稳态的治疗目标。