COBRE: LSU HSC: P4: ER TO GOLGI T & VSMC

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。本项目的目的是确定新生大鼠心室肌细胞和血管平滑肌细胞原代培养中血管紧张素II型1受体（AT1R）和β 2肾上腺素能受体（AR）的er -to-高尔基转运改变的作用。有三个具体目标。第一个目的是确定Rab1和其他囊泡运输调节因子（Sar1, ARF1， Rab2和Rab6）在内质网到高尔基体运输中的作用。第二个目的是确定内质网到高尔基体转运的改变是否与受体信号传导有关，这是操纵Rab1功能的结果。第三个目的是确定Rab1对蛋白表达谱的影响。在第二年，我们进行了研究，以确定从内质网通过高尔基体到G蛋白偶联受体细胞表面的细胞内运输的分子机制，以及它们可能参与心肌细胞肥大的发展。我们研究了：(1)Rab1在新生儿真菌细胞中调节AT1R、α 1- ar和β - ar的转运和信号传导以及增生性反应中的作用。我们已经证明，腺病毒介导的野生型Rab1基因转移不同程度地改变了AT1R、α - 1- ar和β - ar的细胞表面靶向和信号传导，以及受体介导的肥厚反应。(2)二聚化在α 2- ar转运和信号转导中的作用。我们证明，在内质网输出缺陷的alpha2B-AR突变体作为其野生型对应体以及其他alpha2-AR的输出和信号传导的显性负突变体发挥作用。这些数据为GPCR的输出和功能调控提供了新的重要信息。

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. The objective of this project is to determine the role of altered ER-to-Golgi trafficking of angiotensin II type 1 receptor (AT1R) and beta 2 adrenergic receptor (AR) in primary cultures of neonatal rat ventricular myocytes and vascular smooth muscle cells. There are three specific aims. First aim is to define the role of Rab1 and other vesicular transport regulators (Sar1, ARF1, Rab2 and Rab6) in the endoplasmic reticulum-to-Golgi transport. Second aim is to determine if alterations in the ER-to-Golgi transport, as a consequence of manipulating Rab1 function, is involved in receptor signaling. Third Aim is to determine the effect of Rab1 on protein expression profile. In the second year, the studies have been carried out to define the molecular mechanisms underlying the intracellular trafficking from the ER through the Golgi to the cell surface of G protein-coupled receptors and their possible involvement in the development of cardiac myocyte hypertrophy. We have investigated: (1) the role of Rab1 in regulating the transport and signaling of AT1R, alpha1-AR and beta-AR and hypertrophic responses in neonatal mycoytes. We have demonstrated that adenovirus-mediated gene transfer of wild-type Rab1 differentially modified the cell-surface targeting and signaling of AT1R, alpha1-AR and beta-AR as well as receptor-mediated hypertrophic responses. (2) the role of dimerization in alpha2-AR trafficking and signaling. We demonstrated that alpha2B-AR mutant defective in ER export functions as a dominant negative mutant for the export and signaling of its wild-type counterpart as well as other alpha2-AR. These data provide new and important information regarding the regulation of GPCR export and function.