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: 8401896
• 负责人: DOUGLAS R GREEN
• 金额: $ 32.09万
• 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/8401896
• 关键词: Accounting; Address; Affect; Animals; Apoptosis; Apoptotic; Autoimmunity; Autophagocytosis; BAX gene; BCL-2 Protein; BCL2 gene; 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.

程序描述/摘要 发生在动物体内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，这种情况也会发生。 主要是通过线粒体途径。这涉及到线粒体外膜的过程。 通透性(MOMP)，在此基础上细胞色素c扩散到胞浆，激活半胱氨酸蛋白酶， 细胞凋亡就会继续进行。因此，MOMP通常被认为是这种活跃细胞死亡的关键决策点 路径。MOMP既由bcl-2家族的蛋白引起，也受其调控，这种对MOMP的控制是 可能是这个蛋白质家族最重要的功能。这项提议提出了一种新的“统一模式”。 这种蛋白质的功能。在这个模型中，抗凋亡的bcl2蛋白要么起到隔离蛋白质的作用 激活MOMP(通过激活效应器蛋白)，或隔离活性效应器蛋白 他们自己。这两种抑制模式之间的差异，以及它们如何被解除抑制以 促进MOMP和细胞凋亡是这一应用的基础。将实现以下目标。 1.鉴定两种抗凋亡bcl2蛋白功能模式的特性及其在细胞中的作用。 压抑。我们将使用分离的线粒体来探索抗细胞凋亡的bcl2蛋白的特性。 在它们通过隔离直接激活蛋白(模式)来阻止MOMP发挥作用的条件下 1)或通过隔离效应器BAX和BAK(模式2)。抗细胞凋亡药物的相对效率 将根据Bax/BAK的激活和细胞色素c的释放来评估蛋白质。我们将进一步研究 每种模式对去抑制诱发MOMP的相对敏感性。我们建议每个条件都将 以其他模型无法预测的方式显示完全不同的属性。2.分析 细胞内抗凋亡bcl2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是否以及何时参与 细胞压力。在这里，拟议的研究旨在测试和扩展我们的bcl2家族功能模型。 控制MOMP，并建立在活细胞中模式1或模式2占优势的条件。 我们将利用生化和活细胞成像方法来跟踪亲- MOMP背景下的凋亡bcl2效应蛋白。3.确定去中心化的后果 抑制每种方式的抗细胞凋亡的bcl2蛋白对细胞的死亡和存活起作用。 在这里，我们将寻求探索这一模型的后果，通过去抑制细胞死亡，导致 细胞内特定情况下的细胞凋亡。我们将测试模式1和模式2的抑制是否存在差异 对细胞内去抑制的敏感性，以及这如何影响药物去抑制后观察到的“准备死亡”。 抑制和/或改变抗凋亡蛋白的功能。这些研究提供了一系列测试 并对我们提出的新模型进行了探索，具有极大提高认识的潜力 这是控制生命细胞和死亡的基本过程。