CK1delta/epsilon Inhibits Apoptosis in Drosophila

描述(由申请人提供)：细胞凋亡，或程序性细胞死亡，对组织稳态的发展和维持至关重要。Caspase活性的重要负调节因子是一类被称为凋亡抑制因子(IAP)的蛋白质。果蝇IAP基因DIAP1在抑制细胞凋亡中起着关键作用。DIAP1由一组蛋白质调节，称为IAP调节蛋白，与其结合并抑制其活性。果蝇是IAP调节蛋白的重要成员，包括Reaper、HID和Grim。卡迪根实验室进行了一项基因筛查，并发现DCO是果蝇酪蛋白激酶-Delta/epsilon的同源物，当过度表达时，它是HID依赖的细胞凋亡的抑制因子。与其过表达表型一致，翼成像盘中DCO的丢失导致细胞凋亡水平升高和DIAP1蛋白水平降低。我们推测DCO可能通过抑制HID和/或激活DIAP1来抑制细胞凋亡。我将利用细胞培养和体外生化分析来确定DCO是否直接与HID或DIAP1相互作用。此外，我还将使用遗传学方法来确定与DCO依赖的抑制细胞凋亡有关的其他基因。

DESCRIPTION (provided by applicant): Apoptosis, or programmed cell death, is critical for development and maintenance of tissue homeostasis. Important negative regulators of caspase activity are a family of proteins called inhibitors of apoptosis (IAP). A well characterized Drosophila IAP, DIAP1, is critical for inhibition of apoptosis. DIAP1 is regulated by a group of proteins, called IAP regulatory proteins that bind to and inhibit its activity. Well-characterized Drosophila members of the IAP regulatory proteins include Reaper, Hid and Grim. The Cadigan lab has carried out a genetic screen and identified discs overgrown (dco), a Drosophila homologue of casein kinase-delta/epsilon, as an inhibitor of hid-dependent apoptosis when overexpressed. Consistent with its overexpression phenotype, loss of dco in the wing imaginal disc resulted in elevated levels of apoptosis and decreased levels of DIAP1 protein. We hypothesize that Dco either inhibits Hid and/or activates DIAP1 to inhibit apoptosis. I will utilize cell culture and in vitro biochemical analysis to determine whether Dco interacts directly with Hid or DIAP1. In addition, I will use genetic approaches to identify additional genes that are involved in dco-dependent inhibition of apoptosis.