BCL-2 Family Protein interactions in Apoptosis

BCL-2 家族蛋白在细胞凋亡中的相互作用

• 批准号: 8209048
• 负责人: DOUGLAS R GREEN
• 金额: $ 33.25万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8209048
• 关键词: Accounting; Address; Affect; Animals; Apoptosis; Apoptotic; Autoimmunity; Autophagocytosis; BAX gene; BCL-2 Protein; BCL1 Oncogene; Behavior; Binding; Biochemical; Calcium; Caspase; Cell Death; Cell Death Process; Cell Survival; Cells; Cellular Stress; Cessation of life; Complex; Conceptions; Cytosol; Data; Defect; Diffuse; Event; Experimental Designs; Family; Goals; Homeostasis; Life; Malignant Neoplasms; Mammals; Membrane; Mitochondria; Modeling; Outer Mitochondrial Membrane; Pathway interactions; Peptide Hydrolases; Physiological; Process; Production; Program Description; Property; Protein Family; Proteins; Regulation; Relative (related person); Repression; Research Design; Rest; Role; Scheme; Testing; Time; Translating; abstracting; base; cellular imaging; cytochrome c; design; human disease; novel strategies; prevent; protein function; research study

Program Description/Abstract The majority of cell deaths that occur in the animals do so via apoptosis, and in mammals, this happens predominantly by the mitochondrial pathway. This involves the process of mitochondrial outer membrane permeabilization (MOMP), upon which cytochrome c diffuses to the cytosol, caspase proteases are activated, and apoptosis proceeds. Thus, MOMP is often considered the critical decision point for this active cell death pathway. MOMP is both caused and regulated by proteins of the BCL-2 family, and this control of MOMP is likely to be the most important function of this protein family. This proposal addresses a new "unified model" for the function of this protein. In this model, anti-apoptotic BCL-2 proteins act either to sequester the proteins that activate MOMP (by activating the effector proteins), or to sequester the active effector proteins themselves. The differences between these two modes of inhibition, and how they can be de-repressed to promote MOMP and apoptosis, are the bases for this application. The following aims will be addressed. 1. Characterize the properties of the two modes of anti-apoptotic BCL-2 protein function and their de- repression. We will employ isolated mitochondria to probe the properties of anti-apoptotic BCL-2 proteins under conditions in which they function by blocking MOMP by sequestration of direct activator proteins (MODE 1) or by sequestration of the effectors, BAX and BAK (MODE 2). The relative efficiencies of the anti-apoptotic proteins will be assessed in terms of BAX/BAK activation and cytochrome c release. We will further examine the relative sensitivity of each MODE to de-repression to induce MOMP. We propose that each condition will display fundamentally different properties, in a manner that cannot be predicted by other models. 2. Analyze the discrete modes of MOMP inhibition by anti-apoptotic BCL-2 proteins in cells. We will then extend our studies into cells to determine if and when these two modes of anti-apoptotic function are engaged upon cell stress. Here, the proposed studies are designed to test and extend our model of BCL-2 family function in controlling MOMP, and establishing conditions under which MODE 1 or MODE 2 predominate in living cells. We will take advantage of biochemical and live cell imaging approaches to follow the behavior of the pro- apoptotic BCL-2 effector proteins in the context of MOMP. 3. Determine the consequences of de- repression of each mode of anti-apoptotic BCL-2 protein function for cell death and survival in cells. Here we will seek to probe the consequences of this model for cell death by de-repression, leading to apoptosis, under defined situations in cells. We will test if MODE 1 versus MODE 2 inhibition is differentially sensitive to de-repression in cells, and how this affects "priming for death," observed upon pharmacologic de- repression and/or changes in the functions of anti-apoptotic proteins. These studies provide a number of tests and explorations of the new model we propose, and hold the potential to greatly increase of understanding of this fundamental process controlling life cell and death.

项目描述/摘要 动物中发生的大多数细胞死亡都是通过细胞凋亡来实现的，而在哺乳动物中，这种情况就会发生 主要通过线粒体途径。这涉及到线粒体外膜的过程 透化 (MOMP)，细胞色素 c 扩散至细胞质，半胱天冬酶被激活， 并进行细胞凋亡。因此，MOMP 通常被认为是这种主动细胞死亡的关键决策点 途径。 MOMP 是由 BCL-2 家族的蛋白质引起和调节的，MOMP 的这种控制是 可能是该蛋白质家族最重要的功能。该提案提出了新的“统一模型” 为了这个蛋白质的功能。在此模型中，抗凋亡 BCL-2 蛋白可隔离蛋白质 激活 MOMP（通过激活效应蛋白），或隔离活性效应蛋白 他们自己。这两种抑制模式之间的差异，以及如何解除它们的抑制 促进MOMP和细胞凋亡，是该应用的基础。将实现以下目标。 1. 描述抗凋亡 BCL-2 蛋白功能的两种模式的特性及其 de- 抑制。我们将利用分离的线粒体来探测抗凋亡 BCL-2 蛋白的特性 在它们发挥作用的条件下，通过隔离直接激活蛋白（MODE 1) 或通过效应器 BAX 和 BAK 的隔离（模式 2）。抗凋亡的相对效率 将根据 BAX/BAK 激活和细胞色素 c 释放来评估蛋白质。我们将进一步审查 每种模式对去抑制诱导 MOMP 的相对敏感性。我们建议每个条件 以其他模型无法预测的方式显示根本不同的属性。 2. 分析 细胞中抗凋亡 BCL-2 蛋白抑制 MOMP 的离散模式。然后我们将延长 我们对细胞的研究以确定这两种抗凋亡功能模式是否以及何时发挥作用 细胞应激。在这里，拟议的研究旨在测试和扩展我们的 BCL-2 家族功能模型 控制 MOMP，并建立 MODE 1 或 MODE 2 在活细胞中占主导地位的条件。 我们将利用生化和活细胞成像方法来跟踪亲细胞的行为 MOMP 背景下的凋亡 BCL-2 效应蛋白。 3. 确定取消的后果 抑制细胞死亡和存活的抗凋亡 BCL-2 蛋白功能的每种模式。 在这里，我们将寻求探讨这种模型通过去抑制对细胞死亡的影响，从而导致 细胞凋亡，在细胞的特定情况下。我们将测试模式 1 与模式 2 的抑制是否存在差异 对细胞去抑制敏感，以及这如何影响“死亡启动”，通过药理去抑制观察到 抗凋亡蛋白功能的抑制和/或改变。这些研究提供了许多测试 以及我们提出的新模型的探索，并有可能大大增加对 这个控制生命细胞和死亡的基本过程。