Molecular Basis of Tail-Anchored Membrane Protein Targeting

尾锚定膜蛋白靶向的分子基础

基本信息

批准号：
8456146
负责人：
Robert J Keenan
金额：
$ 28.66万
依托单位：
UNIVERSITY OF CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-05 至 2014-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8456146
关键词：
ADP-AlF4 ATP Hydrolysis ATP phosphohydrolase Active Sites Binding Binding Sites Biochemical Biochemical Genetics Biogenesis Biological Cell Death Cell physiology Cells Cellular biology Complex Data Development Endoplasmic Reticulum Ensure Family Goals Health In Vitro Integral Membrane Protein Lead Libraries Malignant Neoplasms Maps Mediating Membrane Membrane Proteins Molecular Molecular Conformation Names Neurodegenerative Disorders Nucleotides Outer Mitochondrial Membrane Pathology Pathway interactions Physiological Play Process Property Proteins Reagent Recombinants Regulation Resolution Role Signal Recognition Particle Signal Transduction Site Staging Structure Substrate Interaction Surface Tail Testing Viral Work base chronic liver disease crosslink directed evolution genetic analysis in vivo insight interdisciplinary approach mutant novel novel therapeutics programs receptor receptor binding trafficking

项目摘要

DESCRIPTION (provided by applicant): The overall goal of this program is to develop a detailed molecular understanding of a novel post- translational targeting pathway that directs insertion of tail-anchored (TA) membrane proteins into the endoplasmic reticulum (ER) membrane. TA proteins constitute a large family of integral membrane proteins that play critical roles in virtually all aspects of cell biology, ranging from intracellular trafficking and viral replication to regulation of cell death. Despite the physiological importance of these proteins, the machinery and molecular mechanisms that mediate recognition, targeting, and insertion of TA proteins into the correct organellar membrane are poorly understood. The targeting and insertion of newly synthesized proteins into the ER membrane is an essential cellular process. For most membrane proteins, this is achieved co-translationally in a process mediated by the signal recognition particle. However, for the nearly 5% of all eukaryotic membrane proteins that are tail-anchored, targeting is achieved post-translationally. This process is mediated by a newly discovered and evolutionarily conserved ATPase, termed TRC40, which interacts with an ER-bound receptor to ensure efficient and accurate TA protein targeting. In an important breakthrough, we have recently determined high-resolution crystal structures of TRC40. Based upon this structural information, the following specific hypotheses will be tested. 1) Recognition of specific physiochemical properties of the targeting signal directs selective TA protein targeting by TRC40. 2) Conformational changes in TRC40 regulate its ATPase activity and TA substrate interactions. 3) The TRC receptor catalyzes these conformational changes through specific interactions with the TRC40-TA substrate complex. Using a powerful interdisciplinary approach, we will establish the fundamental biochemical and biophysical principles that underlie the process of TA protein targeting and insertion. The specific aims of this project are: 1. To determine the molecular basis of selective TA substrate recognition by TRC40 2. To determine how conformational changes in TRC40 regulate ATPase activity and TA substrate interactions 3. To establish how the TRC receptor coordinates targeting and release of TA proteins at the ER membrane

描述（由申请人提供）：该计划的总体目标是对一种新颖的翻译后靶向途径进行详细的分子理解，该途径指导将尾部锚定（TA）膜蛋白插入内质网（ER）膜中。 TA 蛋白构成了一个完整的膜蛋白大家族，它们在细胞生物学的几乎所有方面都发挥着关键作用，从细胞内运输和病毒复制到细胞死亡的调节。尽管这些蛋白质具有生理重要性，但介导 TA 蛋白质识别、靶向和插入正确细胞器膜的机制和分子机制却知之甚少。新合成的蛋白质靶向并插入内质网膜是一个重要的细胞过程。对于大多数膜蛋白来说，这是在信号识别颗粒介导的过程中通过共翻译实现的。然而，对于尾部锚定的所有真核膜蛋白中近 5% 来说，靶向是在翻译后实现的。这一过程是由一种新发现的、进化上保守的 ATP 酶（称为 TRC40）介导的，它与 ER 结合受体相互作用，以确保高效、准确的 TA 蛋白靶向。我们最近取得了一项重要突破，确定了 TRC40 的高分辨率晶体结构。基于该结构信息，将测试以下具体假设。 1) 对靶向信号特定理化特性的识别指导 TRC40 选择性靶向 TA 蛋白。 2) TRC40 的构象变化调节其 ATP 酶活性和 TA 底物相互作用。 3) TRC受体通过与TRC40-TA底物复合物的特异性相互作用来催化这些构象变化。使用强大的跨学科方法，我们将建立 TA 蛋白靶向和插入过程的基本生化和生物物理原理。该项目的具体目标是： 1. 确定 TRC40 选择性 TA 底物识别的分子基础 2. 确定 TRC40 的构象变化如何调节 ATP 酶活性和 TA 底物相互作用 3. 确定 TRC 受体如何协调靶向和释放ER 膜上的 TA 蛋白