Polypeptide Hormone Receptor Recognition and Activation

多肽激素受体识别和激活

• 批准号: 6799392
• 负责人: Kenan Christopher GARCIA
• 金额: $ 38.5万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 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
• 来源: https://reporter.nih.gov/project-details/6799392
• 关键词: X ray crystallography; biological signal transduction; biophysics; calorimetry; conformation; congestive heart failure; diarrhea; drug design /synthesis /production; electrolyte balance; enterotoxins; enzyme activity; guanylate cyclase; hormone receptor; hormone regulation /control mechanism; hypertension; ligands; peptide hormone; pharmacology; protein structure function; receptor binding; recombinant proteins; renal failure; saluretic; small molecule; thermodynamics

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）：多肽激素使细胞表面信号受体调节各种各样的生理功能。我们的体液体积和血压称为体积体内稳态，在很大程度上受到分泌的亚替尼肽（NP）激素及其受体（NPR）的调节，其信号传导与Guanylyl Cyclase（GC）耦合。在心脏，肾脏，肠，眼睛和血管系统等器官中，NP与NPR的相互作用在动员水分排泄和离子传输中起多种和坐标的作用。疏离了这种降压系统的成分在病理状况中表现出高血压（高血压），充血性心力衰竭，肾衰竭和感染性腹泻。这些多样化的疾病是由于无法有效管理流体量而联系在一起的。实际上，NP系统作为治疗靶靶的重要性在2001年通过将脑纳替肽（BNP）引入诊所（NATRECOR（R））作为15年来充血性心力衰竭的首款新治疗方法，在2001年得到了验证。最近在结肠癌和血管生成中存在许多其他针对NP靶向疗法的迹象。 我们的假设是，必须了解NP激素识别的分子基础，以及随后的NP受体激活的细胞内机制，对于最终实现了该系统最有效的调制是必要的。我们提出，与细胞内NP受体受体信号模块相连的细胞外NP受体配体相互作用的聚焦，生化和药理学研究将阐明对分散性过渡的完全机械理解，从而对受体识别对受体的识别进行了激素识别。我们将分别表达NPR细胞外（ECD）和细胞内（ICD）结构域的可溶性，重组形式，分别用于激素识别的生化特征和Guanylyl Cyclase激活。我们将通过X射线晶体学确定静止（无配置）和活性（复合）ECD和ICD的三维结构，以可视化受体中NP多肽激素的受体结合构象，以及受体中配体诱导的构象变化。然后，我们将利用这些结果来设计具有潜在临床实用性的NP激素的经过改良的受体选择性变体。因此，该项目的最终目标既是基本和应用。结构研究将阐明有关受体信号传导的新机械范式，该范式将直接应用于调节各种水肿疾病中体积稳态的治疗目标。