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

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。本课题的目的是研究血管紧张素II 1型受体(AT1R)和β2肾上腺素能受体(AR)在原代培养的新生大鼠心肌细胞和血管平滑肌细胞中内质网向高尔基体转运的变化。有三个具体目标。第一个目的是确定Rab1和其他囊泡转运调节因子(Sar1、ARF1、Rab2和Rab6)在内质网到高尔基体转运中的作用。第二个目的是确定作为操纵Rab1功能的结果，内质网到高尔基体转运的变化是否参与了受体信号转导。第三个目的是确定Rab1对蛋白质表达谱的影响。第二年，研究确定了G蛋白偶联受体从内质网通过高尔基体到细胞表面转运的分子机制，以及它们可能参与心肌细胞肥大的发生。我们研究了：(1)Rab1在调节AT1R、α1-AR和β-AR的运输和信号转导以及调节新生真菌细胞肥大反应中的作用。我们已经证明，腺病毒介导的野生型Rab1基因转移可以不同地改变AT1R、α1-AR和β-AR的细胞表面靶向和信号转导，以及受体介导的肥大反应。(2)二聚体在α2-AR转运和信号转导中的作用。我们证明了内质网出口缺陷的α2B-AR突变体在其野生型和其他α2-AR的出口和信号转导中起显性负突变的作用。这些数据提供了有关GPCR出口和功能监管的新的和重要的信息。

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.