Regulation of apoptosis by Bcl-XL, Bak and Bax

Bcl-XL、Bak 和 Bax 对细胞凋亡的调节

基本信息

批准号：
7921271
负责人：
Chi Li
金额：
$ 5万
依托单位：
UNIVERSITY OF LOUISVILLE
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-01 至 2010-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7921271
关键词：
Address Affect Agonist Animals Apoptosis Apoptotic Bax protein Biochemical Caspase Cell Line Cell Lineage Cell Membrane Permeability Cell physiology Cells Cessation of life Characteristics Development Embryo Endoplasmic Reticulum Fibroblasts Gene Expression Genes Genetic Global Change Goals Hematopoietic Homeostasis ITPR1 gene In Vitro Intracellular Membranes Ion Channel Maintenance Malignant Neoplasms Mediating Membrane Microarray Analysis Mitochondria Molecular Molecular Profiling Mus Mutation Nuclear Oligonucleotides Organelles Pathway interactions Pattern Play Property Protein Family Proteins RNA Interference Recombinants Regulation Research Research Project Grants Resistance Role Signal Transduction Stimulus Tissues bak protein bcl-xlong protein cell suicide cell type design neoplastic cell novel overexpression patch clamp pro-apoptotic protein programs reconstitution research study response

项目摘要

DESCRIPTION (provided by applicant): The development of cancer involves genetic changes leading to alterations in the control of tissue development and homeostatic maintenance, which is tightly regulated by the cellular suicide program, apoptosis. Many tumor cells are resistant to intrinsic and extrinsic apoptotic stimuli, probably due to impaired apoptotic pathways in these cells. Bcl-2 family proteins are major regulators of the cellular response to apoptotic signals. Among them, anti-apoptotic Bcl-XLand pro-apoptotic Bak and Bax have-been shown to play an essential role during apoptosis. Initial studies suggest that in addition to their functions at mitochondria, Bcl-2 proteins also localize on the endoplasmic reticulum (ER) and function to regulate a parallel pathway of apoptosis. Experiments in this proposal are designed to elucidate the detailed molecular mechanisms of Bcl-2 proteins regulating apoptosis. The following specific aims are proposed: 1) Investigate the electrophysiological properties of Bcl-XL, Bak and Bax on the ER membrane and their contribution to the induction of membrane permeabilization during apoptosis. A novel patch-clamp approach to record single ion channel activity will be used to characterize Bcl-2 proteins on the ER membrane. The electrophysiological properties of purified recombinant as well as reexpressed Bcl-XL, Bak and Bax proteins on the ER membrane will be studied. The hypothesis that Bak and Bax form lipidic pores on membranes during apoptosis will also be examined; 2) Study the distinct apoptotic pathways mediated by Bcl-2 family proteins localized on different organelles. Efforts will be made to better characterize caspase pathways mediated by Bak or Bcl-XL localized on the ER or mitochondria using a RNAi approach. The importance of intracellular localizations of pro- and anti-apoptotic Bcl-2 proteins for the regulation of apoptosis will be studied by selectively targeting these proteins to specific organelles. The possible role of Ca2+ in the regulation of distinct apoptotic pathways will be investigated; and 3) Determine whether the expression of Bak and Bax affects cellular physiology and thus cellular response to death signals. Oligonucleotide-based microarray analysis will be performed to examine the changes in gene expression patterns in response to Bak or Bax expression. Genes whose expression may be involved in apoptosis regulation will be further studied.

描述（由申请人提供）：癌症的发展涉及遗传变化，导致控制组织发育和稳态维持的改变，这受到细胞自杀计划的严格调节，凋亡。许多肿瘤细胞对固有和外在凋亡刺激具有抗性，这可能是由于这些细胞中凋亡途径受损所致。 Bcl-2家族蛋白是细胞对凋亡信号反应的主要调节剂。其中，抗凋亡的BCL-Xland促凋亡Bak和Bax的Bax表现为在凋亡过程中起着至关重要的作用。初步研究表明，除了在线粒体上的功能外，Bcl-2蛋白还位于内质网（ER）上，并调节凋亡的平行途径。该提案中的实验旨在阐明调节凋亡的Bcl-2蛋白的详细分子机制。提出了以下具体目的：1）研究BCl-XL，BAK和BAX在ER膜上的电生理特性，及其对凋亡过程中膜透化诱导的贡献。记录单个离子通道活性的新型贴片钳方法将用于表征ER膜上的Bcl-2蛋白。将研究纯化的重组者以及ER膜上重新表达的BCl-XL，BAK和BAX蛋白的电生理特性。还将检查凋亡过程中bak和bax形成膜毛孔的假设。 2）研究由位于不同细胞器上的Bcl-2家族蛋白介导的独特凋亡途径。将采取努力以更好地表征由BAK或BCL-XL介导的caspase途径，使用RNAi方法局部在ER或线粒体上介导的caspase途径。促凋亡和抗凋亡BCl-2蛋白的细胞内定位对调节细胞凋亡的重要性将通过选择性靶向这些蛋白质对特定细胞器进行研究。 Ca2+在调节不同凋亡途径中的可能作用将被研究； 3）确定BAK和BAX的表达是否会影响细胞生理，从而影响细胞对死亡信号的反应。将进行基于寡核苷酸的微阵列分析，以检查响应BAK或BAX表达的基因表达模式的变化。将进一步研究其表达可能参与凋亡调节的基因。