Mechanisms of Golgi Apparatus Protein Recycling

描述：我们的长期目标是对高尔基体进行完整的分子定义 装置生物发生。高尔基体是体内的中央细胞器 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，同时确保新的矢量传输 将蛋白质合成到质膜，是细胞面临的主要挑战 生物学。我们发现所谓的常驻高尔基体膜蛋白可循环利用 以不依赖外壳蛋白的方式从高尔基体连续地 急诊室。这种回收发生在没有任何遗传基因的野生型细胞中。 操作具有直接的医学意义，因为它是 将大量细菌和植物蛋白毒素输送至最终状态 细胞中毒部位。 拟议研究的直接目标是表征分子 产生这种新型的不依赖于外壳蛋白的高尔基体至内质网蛋白的机制 回收途径。我们知道 rab6 和 rab33b 是该通路的调节因子， 并假设 rab 效应器很重要。拟议的具体目标是： 1. 中间体的表征。初步实验表明 晚效膜运输机制蛋白的表达阻断高尔基体 糖基转移酶再循环至内质网。将使用此方法和其他方法 来表征中间体。 2. 确定rab33b和rab6在一个时间内是并联还是串联作用 途径。 Rab6 的定位比 rab33b 更反式。两只兔子演戏吗 并联还是串联？ 3. rab 效应器功能重要性的表征 高尔基体中特定的 rab33b 效应器对 ER 的再循环。 Rab33b 和 rab6 体外 显示出不同的效应器模式，但每个效应器似乎都调节高尔基体 糖基转移酶循环至内质网。从分子意义上讲，这是如何发挥作用的？ 我们建议使用 rab33b 和 rab6 及其效应子作为主要分子 处理解析常驻高尔基体蛋白质回收的机制和途径 急诊室。总之，我们提出了一个机械性的步骤 了解高尔基体生物发生。

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.