ANP RECEPTOR STRUCTURE AND SIGNALING

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。心钠素(ANP)是一种促盐、扩张血管的心脏激素。心钠素在血压和盐液容量调节中起重要作用，其活动异常可能导致心力衰竭、高血压和其他心血管疾病。ANP的活性是由一种特定的细胞膜受体介导的，该受体与其固有的鸟苷环化酶(GCase)活性偶联。该受体作为单跨膜蛋白的二聚体，每个跨膜蛋白由一个胞外ANP结合域和一个胞内GCase催化域组成。ANP与胞外区的结合以一种未知的机制激活了GCase的催化。我们的目的是确定ANP受体的结构，并阐明受体-激素结合和跨膜信号转导的机制。在过去的一年里，我们确定了受体的胞外区(ANPR)与激素ANP的复合体的晶体结构。通过与我们先前确定的脱辅基受体结构的结构比较，我们确定了ANP受体信号转导的结构基础。我们发现了受体二聚体中两个膜旁结构域由激素引起的独特的旋转运动，显然启动了跨膜信号转导。此外，我们已经确定了含有非共价结合的溴离子(而不是天然受体中的氯离子)的ANPR的晶体结构(手稿正在准备中)。我们还获得了两个成分活性ANPR突变体的初步结构。这些研究将有助于更好地理解ANP和ANP相互作用的机制、受体的激活和调节。这些知识将导致心血管疾病更准确的诊断方法和有效的治疗。这些研究还将通过基于结构的药物设计来促进针对心钠素受体的药物的开发。这些药物将用于治疗心力衰竭、高血压和其他心血管疾病。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Atrial natriuretic peptide (ANP) is a cardiac hormone that stimulates salt excretion and dilates blood vessels. ANP plays a major role in blood pressure and salt-fluid volume regulation, and anomaly in its activities may cause heart failure, hypertension, and other cardiovascular diseases. ANP activities are mediated by a specific cell membrane receptor coupled to its intrinsic guanylate cyclase (GCase) activity. The receptor functions as a dimer of a single-span transmembrane protein, each consisting of an extracellular ANP-binding domain and an intracellular GCase catalytic domain. ANP binding to the extracellular domain activates GCase catalysis by an yet unknown mechanism. Our aims are to determine the structure of ANP receptor and to elucidate the mechanisms of receptor-hormone binding and transmembrane signaling. During the past year, we determined the crystal structure of the extracellular domain of the receptor (ANPR) in complex with the hormone ANP. By the structural comparison with the apo-receptor structure that we determined previously, we have identified a structural basis for ANP receptor signaling. We have found a unique hormone-induced rotation motion of the two juxtamembrane domains in the receptor dimmer that apparently initiates transmembrane signal transduction. Additionally, w have determine the crystal structure of the ANPR containing a non-covalently associated bromide ion (instead of chloride ion in the native receptor) (manuscript in preparation). We also have obtained preliminary structures of two constitutively active ANPR mutants. These studies will provide better understanding of the mechanism of ANP and ANP interaction, receptor activation, and regulation. Such knowledge will lead to more accurate diagnosis methods and effective treatments for cardiovascular diseases. These studies will also facilitate development of drugs targeted at the ANP receptor via structure-based drug design. Those drugs will be useful in treating heart failure, hypertension, and other cardiovascular diseases.An