Developmental Regulation of the Cell Cycle in Drosophila

果蝇细胞周期的发育调控

• 批准号: 6907535
• 负责人: LAURA ANNE LEE
• 金额: $ 27.32万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6907535
• 关键词: Drosophilidae; RNA interference; arthropod genetics; biochemical evolution; cell growth regulation; cyclins; developmental genetics; embryogenesis; enzyme activity; enzyme complex; enzyme substrate; gene expression; gene interaction; gene mutation; mutant; protein metabolism; protein protein interaction; protein structure function; serine threonine protein kinase

DESCRIPTION (provided by applicant): The high degree of functional conservation of genes involved in the cell cycle combined with the superb cell biology and genetics of Drosophila make it an ideal model organism for studying cell cycle regulation. During early Drosophila embryogenesis, 3 genes are required for regulation of the streamlined "S-M" cycles characteristic of this developmental stage: pan gu (png), plutonium (plu), and giant nuclei (gnu). Females carrying mutations in any of these genes are sterile because their embryos fail to enter mitosis and over-replicate DNA to form "giant nuclei." PNG encodes a serine/threonine protein kinase, and plu and gnu encode small novel proteins, png, plu, and gnu interact genetically with cyclin B, and Cyclin B protein levels are decreased in these mutants. We recently demonstrated that PNG, PLU, and GNU interact to form an active kinase complex in vitro and that GNU activates PNG by inducing dimerization of PNG-PLU complexes. Additionally, we showed that GNU itself is a substrate for PNG kinase. In a genome-wide biochemical screen, several PNG kinase substrates with vertebrate homologs were recently identified, suggesting that the PNG kinase complex regulates the cell cycle by impinging on evolutionarily conserved components. We now propose to determine whether GNU activates PNG kinase via a dimerization mechanism in vivo and to test whether it is a substrate with potential function as an effector. We plan to determine whether the PNG kinase complex regulates activity of the Anaphase Promoting Complex so as to control Cyclin B levels and entry into mitosis. Finally, an evolutionarily conserved protein, Mat89Bb, has been identified as an in vitro PNG kinase substrate. RNA interference of Mat89Bb in Drosophila results in a phenotype reminiscent of that of the giant nuclei class of genes. We will test whether Mat89Bb is an in vitro substrate of PNG and will isolate Mat89Bb mutants to more precisely determine its role in cell cycle regulation.

描述（由申请人提供）：果蝇细胞周期相关基因的高度功能保守性与其卓越的细胞生物学和遗传学相结合，使其成为研究细胞周期调控的理想模式生物。在果蝇早期胚胎发生过程中，需要3个基因来调控这个发育阶段的流线型“S-M”周期：盘古（png）、钚（plu）和巨核（gnu）。携带这些基因突变的雌性是不育的，因为它们的胚胎不能进入有丝分裂，并过度复制DNA形成“巨核”。“PNG编码丝氨酸/苏氨酸蛋白激酶，plu和gnu编码小的新蛋白，png、plu和gnu与细胞周期蛋白B相互作用，这些突变体中细胞周期蛋白B蛋白水平降低。我们最近证明，PNG，PLU，GNU相互作用，形成一个活跃的激酶复合物在体外和GNU激活PNG通过诱导二聚体的PNG-PLU复合物。此外，我们发现GNU本身是PNG激酶的底物。在一个全基因组的生化筛选，几个PNG激酶底物与脊椎动物同源物最近被确定，这表明PNG激酶复合物调节细胞周期的进化保守组件上的冲击。我们现在建议确定GNU是否通过体内二聚化机制激活PNG激酶，并测试它是否是具有潜在效应功能的底物。我们计划确定PNG激酶复合物是否调节后期促进复合物的活性，从而控制细胞周期蛋白B水平和进入有丝分裂。最后，一个进化上保守的蛋白质，Mat 89 Bb，已被确定为在体外PNG激酶底物。RNA干扰果蝇中的Mat 89 Bb的结果在一个表型让人想起的巨核类基因。我们将测试Mat 89 Bb是否是PNG的体外底物，并将分离Mat 89 Bb突变体以更精确地确定其在细胞周期调控中的作用。