Structural Biology of Cardiovascular Signaling

描述（由申请人提供）： 这个跨学科计划的目的是确定蛋白质在正常心血管信号传导中的结构-功能关系和机制，以及导致疾病的异常。主要组成部分（项目1，2和3）解决了小GTP结合蛋白RhoA，其效应蛋白及其调控机制的机制和结构。RhoA调节血管平滑肌收缩、心肌肥大和应激纤维的形成，其下游效应物Rho激酶最近被认为与高血压有关。RhoA和Rho相关蛋白的细胞机制将在项目1中确定，它们的原子结构将在项目2中确定，它们的亚细胞定位将在项目3中确定，其中蛋白质主要在核心B中产生。Ca 2 +-敏化和Ca 2 +-脱敏的机制将在项目1和3中确定，其信号蛋白的亚细胞定位（敏感性和去敏感性）将在项目3中确定。LPP是一种新发现的平滑肌特异性蛋白质，其分子结构将通过X射线晶体学和NMR光谱学相结合来确定（项目2）。该计划将完成一个强大的结构方法，能量过滤扫描透射电子显微镜（STEM-EELS）的开发，旨在获得有关钙和其他元素的细胞分布和运动的纳米分辨率的成分信息。该方法将用于定量绘制与心脏闰盘和血管平滑肌细胞膜结合的钙，以及在线粒体和其他细胞器中积累的钙，并将这些发现与钙的正常功能和异常作用联系起来。其高度的生物医学意义来自于平滑肌调节蛋白在哮喘和高血压中的参与，以及钙在室颤发展中的重要性，室颤是心脏性猝死的最常见原因。

DESCRIPTION (provided by applicant): The aim of this interdisciplinary program is to determine the structure-function relationships and mechanisms of proteins in normal cardiovascular signaling and subject to abnormalities that cause disease. Major components (Projects 1, 2 and 3) address the mechanism and structure of small GTP-binding protein RhoA, its effector proteins and its mechanisms of regulation. RhoA regulates vascular smooth muscle contraction, cardiac hypertrophy and formation of stress fibers, and its downstream effector, Rho-kinase, was recently implicated in hypertension. The cellular mechanisms of RhoA and Rho-related proteins will be determined in Project 1, their atomic structures in Project 2, and their subcellular localization in Project 3 with proteins largely produced in Core B. The mechanisms of Ca2+-sensitization and the mechanisms of Ca}+-desensitization will be determined in Projects 1 and 3, and its subcellular localization of signaling proteins (sensitivity and de-sensitivity) in Project 3. The molecular structure of LPP, a newly discovered to be smooth muscle specific protein will be determined with combined X-ray crystallography and NMR spectroscopy (Project 2). The program will complete the development of a powerful structural method, energy filtered scanning transmission electron microscopy (STEM-EELS), that is designed to obtain compositional information at nanometer resolution about the cellular distribution and movement of calcium and other elements. This method will be used to quantitatively map calcium bound to a cardiac intercalated disc and vascular smooth muscle cell membranes, and accumulated in mitochondria and other organelles and will relate these findings to the normal functions and abnormal effects of calcium. The high level of biomedical significance of this is derived from the involvement of the smooth muscle regulatory proteins in asthma and high blood pressure, and from the importance of calcium in the development of ventricular fibrillation, the most common cause of sudden cardiac death.