Structure-Function of Bcl-2 Related Apoptosis Regulators in Membranes

描述(申请人提供)：本项目的长期目标是阐明细胞程序性死亡调控的分子机制。了解这种机制是开发有效治疗多种人类疾病的关键，例如癌症的缺血，在这些疾病中，细胞凋亡要么被抑制，要么被加速。我们要解决的基本问题是，Bclxl和Bax在溶液中如何具有相反的功能(分别是抗细胞死亡和促进细胞死亡)，但却显示出相似的结构。其具体目的是确定(1)TBID激活的线粒体外膜促凋亡Bax寡聚的结构基础；(2)BclxL抑制TBID激活的Bax的结构基础。为了完成这个项目，我们将使用特定位点的交联、化学标记和荧光技术来研究TBID、Bax和/或Bclxl之间的相互作用。我们还将在这些蛋白质中产生突变，以阐明结构与功能的关系。通过完成这项系统和彻底的研究，我们将产生关于膜包埋蛋白复合体的有用结构信息，这可能有助于合理设计针对抗细胞死亡复合体或促细胞死亡复合体的化学抑制剂以达到治疗的目的。

DESCRIPTION (provided by applicant): The long-term goal for this project is to elucidate the molecular mechanism for the regulation of programmed cell death. Understanding the mechanism is the key to the development of effective treatments for a wide variety of human diseases such as cancer as ischemia, in which apoptosis is either inhibited or accelerated. The fundamental question we will address is how Bcl-XL and Bax can have opposite functions (anti- and pro- cell death, respectively) yet display similar structures in solution. The specific aims are to determine (1) the structural basis for tBid-activated oligomerization of pro-apoptotic Bax in the mitochondrial outer membrane; and (2) the structural basis for inhibition of tBid-activated Bax by Bcl-XL. To complete the project, we will study the interactions between tBid, Bax and/or Bcl-XL using site-specific cross-linking, chemical labeling and fluorescence techniques. We will also generate mutations in these proteins to elucidate the structure-function relationship. By completing this systematic and thorough investigation, we will generate useful structural information about the membrane-embedded protein complexes, which may facilitate rational design of chemical inhibitors to target either the anti- or the pro-cell death complex for therapeutic benefits.