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于组织稳态的形成和维持至关重要。胱天蛋白酶活性的重要负调节因子是称为凋亡抑制剂（IAP）的蛋白质家族。一个充分表征的果蝇IAP，DIAP 1，是抑制细胞凋亡的关键。DIAP 1由一组称为IAP调节蛋白的蛋白质调节，IAP调节蛋白结合并抑制其活性。充分表征的果蝇IAP调节蛋白的成员包括Reaper、Hid和Grim。Cadigan实验室已经进行了遗传筛选，并确定了过度生长的圆盘（dco），一种果蝇酪蛋白激酶-δ/β的同源物，在过度表达时作为hid依赖性细胞凋亡的抑制剂。与其过表达表型一致，dco在翅成虫盘中的丢失导致细胞凋亡水平升高和DIAP 1蛋白水平降低。我们假设Dco抑制Hid和/或激活DIAP 1以抑制细胞凋亡。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DIAP 1相互作用。此外，我将使用遗传学的方法来确定其他基因参与dco依赖性抑制细胞凋亡。

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.