The regulation of cell death in vivo

描述（由申请人提供）：细胞在多细胞生物的整个生命周期中死亡，细胞死亡的正确调节对有机体健康至关重要，从发育的最初阶段到成年生活。我们建议将两个实验室的互补专业知识结合起来，这两个实验室的研究重点是使用果蝇模型系统对体内细胞死亡的调节。这些实验室带来了独特的工具和新方法来研究果蝇细胞死亡调节因子的复杂激活。这些调节因子：收割者、隐藏者、冷酷者和镰刀者，聚集在一个基因复合体中。值得注意的是，这个复合体中的调控区域比单个基因更高度保守，在功能上也更重要。在这一建议中，我们专注于转录，表观遗传和构象的变化，这是启动细胞死亡所必需的基因组区域。我们已经开发了新的工具和方法来确定如何整合来自发育途径的输入来调节细胞死亡，以及染色质构象如何促进细胞死亡的启动。我们将验证这样的假设，即染色质构象的变化确保凋亡基因在注定死亡的细胞中强劲表达，而在注定存活的细胞中强烈阻断表达。我们将研究三维染色质相互作用在响应不同的内在和外在信号的特定基因组合的快速和精确调节中的作用。我们还将确定来自细胞死亡途径的反馈是否对维持细胞死亡基因激活很重要。大量的初步数据表明，这些研究将会成功。在大规模的基因筛选中，我们已经确定了特定细胞亚群生理性死亡所需的基因。这些包括序列特异性转录调节因子，以及对染色质构象和三维染色体结构重要的基因。我们将研究这些基因如何激活细胞死亡基因复合体。在这项资助结束时，我们将开发出一个功能验证的生理性细胞死亡控制模型。此外，我们将描述基因复合物和共享调控区域的一般原则。

DESCRIPTION (provided by applicant): Cells die throughout the lifespan of multicellular organisms, and the correct regulation of cell death is critical for organismal health, from the earliest stages of development through adult life. We propose to bring together the complementary expertise of two labs whose research has focused on the regulation of cell death in vivo, using the Drosophila model system. These labs bring unique tools and novel approaches to study the complex activation of the Drosophila cell death regulators. These regulators: reaper, hid, grim and sickle, are clustered together in a gene complex. Remarkably, the regulatory regions in this complex are more highly conserved, and are functionally more important, than the individual genes. In this proposal, we focus on transcriptional, epigenetic and conformational changes in this genomic region that are required to initiate cell death. We have developed new tools and approaches to determine how the input from developmental pathways is integrated to regulate cell death, and how chromatin conformation contributes to the initiation of cell death. We will test the hypothesis that changes in chromatin conformation ensure robust expression of pro- apoptotic genes in cells fated to die, while strongly blocking expression in cells destined to live. We will examine the role of three dimensional chromatin interactions in this rapid and precise regulation of specific combinations of genes in response to different intrinsic and extrinsic signals. We will also determine whether feedback from the cell death pathway is important for the maintenance of cell death gene activation. Extensive preliminary data indicate that these studies will be successful. In a large-scale genetic screen, we have identified genes that are required for the physiologic death of a precise subset of cells. These include sequence specific transcriptional regulators, and genes important for chromatin conformation and three dimensional chromosome architectures. We will investigate how these genes activate the cell death gene complex. At the conclusion of this grant, we will have developed a functionally validated model of the control of physiologic cell death. In addition, we will have described general principles for the regulation of gene complexes and shared regulatory regions.