CSN5 in Drosophila Oogenesis: Roles in Ecdysone Signaling and Border Cell Migration

摘要CSN5编码COP9信号体(CSN)的一个亚基，CSN是一个多亚基复合体，参与了以蛋白质稳定性和泛素依赖的降解为中心的多种细胞调控事件。在受调控的蛋白质中，突出的是信号依赖的转录因子，如Jun，NFKB，核类固醇激素受体，以及细胞周期调节因子，如p27Kip1和p53(在Schwechheimer和Den，2001中综述)。最近发现，裂解酵母中的CSN5对应物调节一种名为NEDD8的泛素样蛋白与E3泛素连接酶的附着(Lyapina等人，2001年)。因此，CSN调控的多样性可能是通过特定蛋白质的选择性降解或稳定来实现的。在这里，贝肯多夫博士特别感兴趣的是CSN在对类固醇激素蜕皮激素的反应中所起的作用，以及在果蝇卵子发生过程中边缘细胞的迁移。这项建议有三个具体目标：确定CSN5是否与蜕皮激素受体和TAIMAN共激活子一起参与蜕皮激素反应；确定CSN5在调节边界细胞迁移方面是独立发挥作用，还是作为CSN复合体的一部分发挥作用。确定CSN5(和CSN)是否通过NEDD8-泛素连接酶-蛋白酶体途径引导受体降解。这一建议对博士后研究员以及研究生和本科生的教育发展具有更广泛的影响。除了在实验室培养他们的实验能力外，博士后和学生都参加每周一次的实验室会议、多个实验室的研究报告和期刊俱乐部。这项研究本身的更广泛影响集中在控制正常发育和影响人类健康的疾病上。泛素依赖的蛋白质降解参与细胞周期、信号转导和抗原处理等基本细胞过程的调节。COP9信号体是一种蛋白质复合体，在信号转导和Ub依赖的蛋白降解之间发挥作用。它控制的一些底物是关键的肿瘤抑制基因，如p53，或原癌基因，如p27kip1。在目前的方案中，我们研究了CSN对类固醇激素调节和细胞迁移的影响。对类固醇激素信号的精确控制是人类发育和生殖所必需的。此外，几种最常见和最具破坏性的人类癌症，包括乳腺癌和前列腺癌，都依赖于类固醇激素信号。细胞迁移与胚胎构型、器官形成和免疫反应有关。侵袭性细胞迁移也是晚期肿瘤发生的一部分，包括正常组织的浸润和从肿瘤起始部位到体内其他组织的转移。

SummaryCSN5 encodes one subunit of the COP9 signalosome (CSN), a multisubunit complex that has been implicated in a wide variety of cellular regulatory events centered around protein stability and ubiquitin-dependent degradation. Prominent among the regulated proteins are signal dependent transcription factors, such as Jun, NFKB, and the nuclear steroid hormone receptors, and cell cycle regulators like p27Kip1 and p53 (reviewed in Schwechheimer and Deng, 2001). It was recently shown that the CSN5 counterpart in fission yeast regulates the attachment of a ubiquitin-like protein called NEDD8 to E3 ubiquitin ligases (Lyapina et al, 2001). Thus, the wide variety of CSN regulation may be achieved by the selective degradation or stabilization of specific proteins. Here Dr. Beckendorf is particularly interested in the role of the CSN in the response to the steroid hormone ecdysone and in the migration of the border cells during Drosophila oogenesis. This proposal has three specific aims: Establish whether CSN5 participates in the ecdysone response along with the ecdysone receptor and the TAIMAN coactivator.Establish whether, in regulating the migration of border cells, CSN5 acts independently or as part of the CSN complex. Establish whether CSN5 (and the CSN) directs receptor degradation through the NEDD8-ubiquitin ligase-proteasome pathway.This proposal has broader impacts on the educational development of postdoctoral fellows, and both graduate and undergraduate students. In addition to developing their experimental abilities in the laboratory, both postdocs and students participate in weekly laboratory meetings and multi-laboratory research presentations and journal clubs. The broader impacts of the research itself center around the control of normal development and around diseases that affect human health. Ubiquitin-dependent protein degradation is involved in the regulation of essential cellular processes such as the cell cycle, signal transduction and antigen processing. The COP9 signalosome is a protein complex that acts at the intersection between signal transduction and Ub-dependent proteolysis. Some of the substrates it controls are crucial tumor suppressors, such as p53, or proto-oncogenes, such as p27kip1. In the current proposal we study the impact of the CSN on steroid hormone regulation and cell migration. Precise control of steroid hormone signaling is required for human development and reproduction. In addition, several of the most frequent and most devastating human cancers, including both breast and prostate cancer, are dependent on steroid hormone signaling. Cellular migrations are involved in embryonic patterning, organ formation, and immune responses. Invasive cell migrations are also part of late stage oncogenesis, including infiltration of normal tissues and metastatic spread from the initial site of the tumor to other tissues in the body.