PROTEIN TRANSPORT INTO MAMMALIAN ENDOPLASMIC RETICULUM

这个项目的长期目标是了解分子机制 蛋白质通过其被运输穿过或插入哺乳动物体内 内质网（ER）膜。 我们最近建立了一个系统 重组的脂蛋白体， 用纯化的膜蛋白和纯磷脂。 最低 内质网膜的转运装置似乎只包括 Sec61p-三个亚基和TRAM蛋白的复合物。 我们现建议 从这些方面深入分析易位的机制， 单个组件。 具体来说，我们将使用交联和 重构方法，以解决以下问题：1。 有哪些 分子水平上的易位步骤 2. 的功能是什么 Sec61p复合体3. TRAM蛋白如何促进易位？ 我们还将寻找可能需要的其他组件， 易位的翻译后模式，用于易位的再循环 组分和易位过程的调节。 我们相信，我们的研究将大大有助于 了解生物合成中的第一个决定性步骤， 一类蛋白质，包括分泌蛋白、血浆蛋白 膜，溶酶体和分泌途径的所有细胞器。

The long-term goal of this project is to understand the molecular mechanism by which proteins are transported across or are inserted into the mammalian endoplasmic reticulum (ER) membrane. We have recently established a system of reconstituted proteoliposomes which reproduces the translocation process with purified membrane proteins and pure phospholipids. The minimum translocation apparatus of the ER membrane seems to comprise only the Sec61p- complex of three subunits and the TRAM protein. We now propose to thoroughly analyze the mechanism of translocation, in terms of these individual components. Specifically, we will use crosslinking and reconstitution methods to address the following questions: 1. What are the steps of translocation on a molecular level? 2. What are the functions of the Sec61p- complex? 3. How does the TRAM protein facilitate translocation? We will also search for additional components which may be required for the postranslational mode of translocation, for the recycling of translocation components and for the regulation of the translocation process. We believe that our studies will contribute significantly to the understanding of the first and decisive step in the biosynthesis of a large class of proteins which includes secretory proteins, proteins of the plasma membrane, of lysosomes and of all organelles of the secretory pathway.