Mechanisms of Golgi Apparatus Protein Recycling

描述：我们的长期目标是一个完整的高尔基体分子定义 器官生物发生高尔基体是细胞内的中心细胞器， 人体细胞的分泌途径。细胞如何产生明显稳定的 分泌途径中的下游细胞器，特别是高尔基体 设备，同时确保新的矢量运输 将合成的蛋白质运输到质膜上，是细胞中的一个主要挑战。 生物学我们发现所谓的常驻高尔基体膜蛋白 以不依赖于外壳蛋白的方式从高尔基体连续地 急诊室这种再循环发生在野生型细胞中，在没有任何遗传修饰的情况下， 操作，并具有直接的医学意义，因为它是一个关键步骤， 将大量细菌和植物蛋白毒素输送到它们的最终 细胞中毒的部位。 拟议研究的直接目标是表征分子 产生这种新的不依赖于外壳蛋白的高尔基体-内质网蛋白的机制 回收途径。我们知道rab 6和rab 33 b是这一通路的调节因子， 并假设RAB效应器是重要的。拟议的具体目标是： 1.中间体的表征。初步实验表明， 晚期作用的膜运输机制蛋白的表达阻断高尔基体 糖基转移酶再循环到ER。将使用这种方法和其他方法 以表征中间体。 2.确定rab 33 b和rab 6在一段时间内是并联还是串联作用。 通路Rab 6比Rab 33 b更反式定位。这两只兔子是不是 并联还是串联？ 3. rab效应子的功能重要性的表征和 特别是rab 33 b效应器在高尔基体ER再循环。Rab 33 b和Rab 6体外 显示出不同的效应器模式，但每一个似乎都调节高尔基体 糖基转移酶循环到ER。这在分子意义上是如何运作的呢？ 我们建议使用rab 33 b和rab 6及其效应子作为主要分子 把手解剖机制和途径的居民高尔基体蛋白回收， 急诊室最后，我们提出了一个机械的步骤，在我们的 了解高尔基体的生物发生。

DESCRIPTION: Our long-term goal is a complete molecular definition of Golgi apparatus biogenesis. The Golgi apparatus is the central organelle within the secretory pathway of human cells. How the cell generates apparently stable downstream organelles within the secretory pathway, specifically, the Golgi apparatus, while at the same time ensuring vectorial transport of newly synthesized protein to the plasma membrane, is a major challenge in cell biology. We find so-called resident Golgi apparatus membrane proteins recycle continuously in a coat protein independent manner from the Golgi apparatus to the ER. This recycling occurs in wild type cells in the absence of any genetic manipulation and is of immediate medical significance as it is a key step in the delivery of numerous bacterial and plant protein toxins to their ultimate site of cellular intoxication. The immediate aims of the proposed research are to characterize the molecular mechanisms that produce this novel coat-protein-independent Golgi-to-ER protein recycling pathway. We know that rab6 and rab33b are regulators of the pathway, and assume that rab effectors are important. The proposed Specific Aims are: 1. Characterization of intermediates. Preliminary experiments suggest that expression of late acting, membrane trafficking machinery proteins block Golgi glycosyltransferase recycling to the ER. This and other approaches will be used to characterize intermediates. 2. Determination if rab33b and rab6 act in parallel or in series within a pathway. Rab6 is more trans in localization than rab33b. Do the two rabs act in parallel or in series? 3. Characterization of the functional importance of rab effectors and in particular rab33b effectors in Golgi to ER recycling. Rab33b and rab6 in vitro display a different pattern of effectors yet each seems to regulate Golgi glycosyltransferase cycling to the ER. How does this work in a molecular sense? We propose to use rab33b and rab6 and their effectors as the prime molecular handles to dissect mechanism and pathway of resident Golgi protein recycling to the ER. In conclusion, we propose a mechanistic step forward in our understanding of Golgi apparatus biogenesis.