Mechanisms of Bax Activation

Bax 激活机制

基本信息

批准号：
8002737
负责人：
Xu Luo
金额：
$ 10.14万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
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：
2010-01-20 至 2010-12-31
项目状态：
已结题

项目摘要

Apoptosis, or programmed cell death, is a biochemical pathway critical to normal development and tissue homeostasis in multi-cellular organisms. Aberrant suppression of apoptosis is a requisite contributor to human cancer. The long-term objective of this application is to elucidate the intracellular pathways and the molecular mechanisms that lead to apoptosis. The Bcl-2 family proteins are major regulators of apoptosis. Genetic and biochemical studies establish that two of the Bcl-2 family proteins, Bax and Bak, are requisite mediators of the mitochondria-dependent apoptotic pathway. In order to initiate apoptosis, Bax needs to undergo an activation process, which involves its mitochondrial translocation, the formation of Bax homo- oligomers, and the subsequent damage of mitochondria, a hallmark of apoptosis. The mechanisms of this activation process remain poorly understood. Using techniques of biochemistry and molecular biology, this proposal aims at determining the molecular mechanisms of Bax activation during apoptosis. In Aim 1, we will determine the mechanism of mitochondrial translocation of Bax. The role of mitochondrial targeting sequence(s), conformational changes, and dimeric states of Bax in its mitochondrial translocation will be examined. In Aim 2, the helices and amino acid residues critical for the oligomerization of Bax will be defined. Mutational study and biochemical assays will be used to examine the role of homo-oliomerization in the apoptotic activity of Bax. In Aim 3, we will determine the mechanism of Bax activation by upstream activators. In addition, loss-of-functionstudies using siRNA will be combined with in vitro studies to examine the role of other Bcl-2 family proteins in the activation of Bax during apoptosis. These studies will determine the molecular mechanisms of Bax activation and will help elucidate the pathways that lead to apoptosis. Upon a successful completion, this proposal will not only provide basic knowledge on the regulation of apoptosis, but may also provide new insights on the design of therapeutic agents against cancer.

凋亡或程序性细胞死亡是一种生化途径，对正常发育和组织至关重要多细胞生物中的稳态。异常抑制细胞凋亡是有必要的贡献者人类癌。该应用的长期目标是阐明细胞内途径和导致凋亡的分子机制。 Bcl-2家族蛋白是凋亡的主要调节剂。遗传和生化研究确定，Bcl-2家族蛋白中的两种Bax和Bak是必需的线粒体依赖性凋亡途径的介体。为了启动凋亡，Bax需要经历激活过程，涉及其线粒体易位低聚物以及随后的线粒体损害，这是凋亡的标志。这个机制激活过程仍然了解不足。使用生物化学和分子生物学技术，这建议旨在确定凋亡过程中BAX激活的分子机制。在AIM 1中，我们将确定Bax线粒体易位的机理。线粒体靶向的作用 Bax的序列，构象变化和线粒体易位的二聚体状态将是检查。在AIM 2中，螺旋和氨基酸残基至关重要的BAX寡聚化定义。突变研究和生化测定将用于检查同构化在 Bax的凋亡活性。在AIM 3中，我们将通过上游确定Bax激活的机制激活剂。此外，使用siRNA的功能丧失研究将与体外研究结合起来，以检查其他Bcl-2家族蛋白在凋亡过程中BAX激活中的作用。这些研究将确定 Bax激活的分子机制，将有助于阐明导致凋亡的途径。成功完成后，该提案不仅将提供有关监管的基本知识凋亡，但也可能提供有关针对癌症的治疗剂设计的新见解。