Angiotensin II Receptor Signaling Domains

血管紧张素II(AngII)是一种通过血管紧张素II介导的血管肥大的强有力的刺激因子 血管平滑肌细胞的类型受体(AT1R)。它的许多重要产出都来自于 EGF受体(EGF-R)的反式激活，这需要中国证监会的初始激活，并依赖于 NAD(P)H氧化酶(NOx)产生的活性氧(ROS)。富含小窝蛋白的脂筏 (CE/LRM)是特殊的膜微域，其中信号分子如EGFR 通过与小窝蛋白-1(Cav1)的相互作用进行区隔。我们发现血管紧张素转换酶II促进AT1R的贩运 进入CE/LRM，这是EGF-R反式激活和EGF-R从CE/LRM出口所必需的， 导致Py-EGFR与pY14Cav1在局部粘连处共定位。我们还发现AT1R 向CE/LRM的迁移取决于ROS、CSRC、微管/肌动蛋白细胞骨架和Cav1；然而， 人们对潜在的组织分子机制知之甚少。CABL是一种F-肌动蛋白结合的非受体 连接受体酪氨酸激酶和肌动蛋白重塑的酪氨酸激酶。Cav1是一种主要依赖ROS的 电缆酪氨酸磷酸化靶标。我们发现AT1R能激活VSMCs和小鼠主动脉中的CABL，并且 将电缆绑定提升到AT1R，这依赖于ROS、CSRC和CAV1。初步数据引导我们 假设CABL作为ROS、Cav1和肌动蛋白细胞骨架依赖的中心组织者发挥作用 AT1R转运和信号转导，可能参与血管肥大。为了检验这一假设，AIM1 将表征AT1R和CABL的相互作用，并确定ANG II激活CABL的机制。 AIM2将探索NOx衍生的ROS激活CABL的机制，重点是氧化 直接与AT1R结合的SHP-2失活，对中国证监会起负面调节作用。AIMS将探索 CABL介导血管紧张素Ⅱ刺激的AT1R迁移到CE/LRM的分子机制 局灶性粘连和肥大的PY-EGF-R信号复合体，集中在电缆下游靶点， Cortactin和Y14Cav1。AIM4将评估CABL在血管紧张素Ⅱ诱导的血管肥厚中的功能作用 活着。基因敲除小鼠和细胞，活细胞成像，细胞分离，蛋白质-蛋白质相互作用和分子 将使用生物分析。这些研究应该为第二代血管生成素的组织提供新的见解 为心血管疾病的新治疗分配提供信号并确定潜在的新靶点。

Angiotensin II (AngII) is a potent stimulator of vascular hypertrophy which is mediated through the Ang II typel receptor (AT1R) in vascular smooth muscle cells (VSMCs). Many of its important outputs result from transactivation of the EGF receptor (EGF-R), which requires initial activation of cSrc and which is dependent on reactive oxygen species (ROS) derived from NAD(P)H oxidase (Nox). Caveolin-enriched lipid rafts (CE/LRM) are specialized membrane microdomains where signaling molecules such as EGFR are compartmentalized via interacting with caveolin-1 (Cav1). We showed that Ang II promotes AT1R trafficking into CE/LRM, which is required for transactivation of EGF-R and egress of EGF-R from the CE/LRM, resulting in colocalization of pY-EGFR with pY14Cav1 at focal adhesions. We also found that AT1R migration into CE/LRM is dependent on ROS, cSrc, microtubules/actin cytoskeleton and Cav1; however, underlying, organizing molecular mechanisms are poorly understood. cAbl is a F-actin binding non-receptor tyrosine kinase that links receptor tyrosine kinase and actin remodeling. Cav1 is a major ROS-dependent tyrosine phosphorylation target of cAbl. We show that AT1R activates cAbl in VSMCs and mouse aorta, and promotes cAbl binding to the AT1R, which are dependent on ROS, cSrc and Cav1. Preliminary data led us to hypothesize that cAbl functions as a central organizer for ROS, Cav1 and actin cytoskeleton-dependent AT1R trafficking and signaling, which may contribute to vascular hypertrophy. To test this hypothesis, AIM1 will characterize the interaction of AT1R and cAbl, and define the mechanisms of cAbl activation by Ang II. AIM2 will explore the mechanisms by which cAbl is activated by Nox-derived ROS with focusing on oxidative inactivation of SHP-2 which binds directly to AT1R and negatively regulates cSrc. AIMS will explore the molecular mechanisms by which cAbl mediates Ang ll-stimulated AT1R migration into CE/LRM, formation of pY-EGF-R signaling complex at focal adhesions and hypertrophy with focus on cAbl downstream targets, cortactin and Y14Cav1. AIM4 will assess the funcional role of cAbl in Ang ll-induced vascular hypertrophy in vivo. Knockout mice and cells, live cell imaging, cell fractionation, protein-protein interaction and molecular biological aanlysis will be used. These studies should provide new insights into the organization of Ang II signaling and identify potential new targets for novel therapeutic apporaches to cardiovascular diseases.