Programmed Cell Death (Apoptosis) in Drosophila

果蝇的程序性细胞死亡（细胞凋亡）

• 批准号: 6931948
• 负责人: ANDREAS BERGMANN
• 金额: $ 27.94万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-19 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6931948
• 关键词: Drosophilidae; apoptosis; biological models; cysteine endopeptidases; developmental genetics; enzyme activity; enzyme inhibitors; enzyme mechanism; genetic regulation; genetic screening; homeostasis; mitogen activated protein kinase; oncogenes

Apoptosis is a physiological process of cell death that is critical for normal development and tissue homeostasis. Defects in the regulation of apoptotic mechanisms contribute to the pathogenesis of multiple diseases, including those with reduced rates of apoptosis (cancer, autoimmunity) or with excessive cell death (neurodegeneration, stroke, myocardial infarction). The primary focus of this proposal is to elucidate the genetic mechanisms that regulate and execute cell death in the context of a developing organism. We are utilizing the highly accessible genetic model organism Drosophila melanogaster. In Drosophila, the basic components of the cell death machinery are conserved. Homologs of caspases, ced-4/Apaf-1, and lAPs have been identified. We have performed a genetic mutagenesis screen aimed at identifying mutants in components of the cell death machinery in Drosophila. These mutants are extremely informative for the genetic dissection of the Drosophila cell death pathway. For instance, genetic analysis of a subset of these mutants identified the Ras/MAPK pathway as important negative regulator of Hid, one of the cell death-inducing genes in flies. This finding is significant as 30% of human tumors are associated with oncogenic forms of Ras. Therefore, we devote two specific aims to analyze this interaction. We will determine the biochemical basis of Ras/MAPK-induced inhibition of Hid, and we will molecularly identify an additional gene, shes, that appears to control the MAPK/Hid interaction. Caspases, the principal effectors of apoptosis, are under tight genetic control, lAPs inhibit the activity of caspases, whereas Ced-4/Apaf-l-like proteins are required for their activation. How lAPs and Ced-4/Apaf-1- like proteins coordinate caspase activation is poorly understood. Using mutants of the Drosophila homologs of lAPs and Ced-4/Apaf-1 we will dissect the genetic requirement of these genes for the control of caspase activation. Finally, we propose a novel approach that will permit us to isolate additional as yet uncharacterized components of the Drosophila cell death pathway. The information obtained in these experiments will provide new insights into human diseases where deregulation of apoptosis is known to occur and may lead to new strategies for therapeutic intervention.

凋亡是细胞死亡的生理过程，对正常发育和组织稳态至关重要。凋亡机制调节的缺陷有助于多种疾病的发病机理，包括凋亡率降低（癌症，自身免疫性）或过度细胞死亡（神经变性，中风，心肌梗死）的疾病。该提案的主要重点是阐明在发育中的生物体中调节和执行细胞死亡的遗传机制。 我们正在利用高度可访问的遗传模型有机体果蝇。在果蝇中，细胞死亡机器的基本成分是保守的。已经确定了胱天蛋白酶，CED-4/APAF-1和圈的同源物。我们已经进行了旨在鉴定果蝇细胞死亡机械组成部分中突变体的遗传诱变筛查。这些突变体对于果蝇细胞死亡途径的遗传解剖非常有用。例如，对这些突变体子集的遗传分析确定RAS/MAPK途径是HID的重要负调节剂，这是细胞死亡诱导的之一 果蝇中的基因。这一发现显着，因为30％的人类肿瘤与致癌有关 Ras的形式。因此，我们将两个特定的目的用于分析这种相互作用。我们将确定RAS/MAPK诱导的HID抑制的生化基础，我们将分子鉴定出一种似乎控制MAPK/HID相互作用的其他基因。 胱天蛋白酶是细胞凋亡的主要效应因子，处于严格的遗传控制下，圈抑制了胱天蛋白酶的活性，而CED-4/APAF-L样蛋白的激活需要CED-4/APAF-L样蛋白。圈和CED-4/APAF-1-喜欢蛋白如何坐标caspase激活的方式鲜为人知。利用乳清果和Ced-4/apaf-1的果蝇同源物的突变体，我们将剖析这些基因的遗传需求，以控制caspase激活。最后，我们提出了一种新颖的方法，该方法将使我们能够隔离果蝇细胞死亡途径的其他尚未表征的成分。在这些实验中获得的信息将为人类疾病提供新的见解，在这些疾病中，已知对凋亡的放松调节，并可能导致治疗干预的新策略。