Developmental Regulation of the Cell Cycle in Drosophila

果蝇细胞周期的发育调控

基本信息

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
项目类别：
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

项目摘要

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型生物。在果蝇早期胚胎发生过程中，需要 3 个基因来调节该发育阶段的流线型“S-M”循环特征：盘古 (png)、钚 (plu) 和巨核 (gnu)。携带这些基因突变的雌性是不育的，因为它们的胚胎无法进入有丝分裂并过度复制DNA以形成“巨核”。 PNG 编码丝氨酸/苏氨酸蛋白激酶，plu 和 gnu 编码新型小蛋白，png、plu 和 gnu 与细胞周期蛋白 B 发生遗传相互作用，并且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 和 GNU 在体外相互作用形成活性激酶复合物，并且 GNU 通过诱导 PNG-PLU 复合物二聚化来激活 PNG。此外，我们还表明 GNU 本身就是 PNG 激酶的底物。在全基因组生化筛选中，最近鉴定了几种具有脊椎动物同源物的 PNG 激酶底物，表明 PNG 激酶复合物通过影响进化上保守的成分来调节细胞周期。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子功能的底物。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，一种进化上保守的蛋白质 Mat89Bb 已被鉴定为体外 PNG 激酶底物。果蝇中 Mat89Bb 的 RNA 干扰导致的表型让人想起巨核类基因的表型。我们将测试Mat89Bb是否是PNG的体外底物，并将分离Mat89Bb突变体以更精确地确定其在细胞周期调节中的作用。