A Novel Role for MAGI1 in regulating non-canonical LATS signaling and atherosclerotic plaque formation

项目摘要 促动脉粥样硬化的刺激，如炎性细胞因子和血流紊乱(d-flow)，显著地促进了 内皮细胞(EC)炎症，以及随后的动脉粥样硬化斑块形成。膜相关 鸟苷酸激酶-1(MAGI1)是一种含有6个PSD95/DiscLarge/ZO-1(PDZ)结构域的支架蛋白。 鸟氨酸激酶区，以及位于第一和第二PDZ结构域两侧的两个WW结构域。MAGI1员工 具有紧密和粘连的连接，但其胞质和细胞核的定位也已有报道。最近， 一项全基因组关联研究显示，MAGI1基因座突变与 炎症性肠病和牛皮癣关节炎。EC炎症在调节中的重要作用 这些疾病的表型和严重程度在临床上也与加速 动脉粥样硬化(AS)和增加心血管疾病的风险已经得到了很好的证实。在预赛中 数据，我们已经发现MAGI1翻译后修饰(PTM)在调节EC中的关键作用 炎症和细胞凋亡。MAGI1 S741磷酸化导致RAP1活化和大肿瘤 抑制因子1(LATS1)(但不是Yes相关蛋白[YAP]磷酸化，这是一个典型的途径 受LATS1监管)。MAGI1去SUMO化导致MAGI1和p90RSK共移位到 细胞核，在那里它们上调炎性基因的表达。在拟议的研究中，我们假设 MAGI1 PTMS的动态调节(磷酸化和去SUMO)导致胞浆RAP1和非胞浆RAP1 典型的LATS信号激活和p90RSK核转位。MAGI1在胞浆和胞核中的表达 间隔区在调控内皮细胞炎症和细胞凋亡以及随后的动脉粥样硬化形成中起着关键作用。 目标1将确定MAGI1 S741磷酸化促进EC炎症和 细胞凋亡。AIM 2将确定MAGI1去苏糖化在核转位和促进EC中的作用 发炎。在目标3中，我们将确定MAGI1和LATS1/2在加速AS中的作用。这是一种 MAGI1 PTMS包括磷酸化和去SUMO化诱导的EC炎症是新的和亮点 确定含有PDZ结构域的分子和p90RSK如何协调调节EC的重要性 炎症和细胞凋亡。该项目的长期目标是确定MAGI1磷酸化的作用 和(去)糖基化在调节MAGI1亚细胞定位和MAGI1依赖的信号和TO中的作用 阐明MAGI1诱导内皮细胞炎症和凋亡并促进其发生的分子机制 动脉粥样硬化的形成。这将提供对导致不良结果的基本信号的更深入的理解 与AS相关的心血管疾病。

Project Summary Pro-atherogenic stimuli such as inflammatory cytokines and disturbed flow (d-flow) significantly contribute to endothelial cell (EC) inflammation, and subsequent atherosclerotic plaque formation. Membrane-associated guanylate kinase-1 (MAGI1) is a scaffold protein that contains six PSD95/DiscLarge/ZO-1 (PDZ) domains, a guanylate kinase domain, and two WW domains flanked by the first and second PDZ domains. MAGI1 associates with the tight and adherens junction, but its cytosolic and nuclear localization has also been reported. Recently, a genome-wide association study has revealed a strong association of mutations in Magi1 gene locus with inflammatory bowel disease and psoriatic arthritis. The significant contribution of EC inflammation in regulating the phenotype and severity of these diseases, which are also clinically associated with accelerated atherosclerosis (AS) and increased risk of cardiovascular diseases, has been well established. In the preliminary data, we have found the critical role of MAGI1 post-translational modifications (PTMs) in regulating EC inflammation and apoptosis. MAGI1 S741 phosphorylarion results in the activation of Rap1 and large tumor suppressor 1 (LATS1) (but not Yes-associated protein [YAP] phosphorylation, which is a canonical pathway regulated by LATS1). MAGI1 de-SUMOylation leads to the co-translocation of MAGI1 and p90RSK to the nucleus, where they up-regulate inflammatory gene expression. In the proposed study, we hypothesize that dynamic modulation of MAGI1 PTMs (phosphorylation and de-SUMOylation) leads to cytosolic Rap1 and non- canonical LATSs signaling activation, and p90RSK nuclear translocation. MAGI1 in both cytosolic and nuclear compartments plays critical roles in regulating EC inflammation and apoptosis and subsequent atherogenesis. Aim 1 will identify the mechanism by which MAGI1 S741 phosphorylation promotes EC inflammation and apoptosis. Aim 2 will determine the role of MAGI1 de-SUMOylation in nuclear translocation and promoting EC inflammation. In aim 3, we will determine the role of MAGI1 and LATS1/2 in accelerating AS. The concept of the MAGI1 PTMs including phosphorylation- and de-SUMOylation-induced EC inflammation is novel and highlights the importance of determining how this PDZ domain-containing molecule and p90RSK coordinately regulate EC inflammation and apoptosis. The long–term goals of this project are to identify the role of MAGI1 phosphorylation and (de)SUMOylation in regulating MAGI1 subcellular localization and MAGI1-dependent signaling and to elucidate the molecular mechanisms by which MAGI1 induces EC inflammation and apoptosis and promotes atherogenesis. This will provide deeper understanding of the basic signaling responsible for the poor outcome of AS-related cardiovascular diseases.