Developmental Control of Cell Cycle Entry

细胞周期进入的发育控制

• 批准号: 6526043
• 负责人: SANDER VAN DEN HEUVEL
• 金额: $ 29.41万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6526043
• 关键词: Caenorhabditis elegans; biological signal transduction; cell cycle; cell cycle proteins; cell growth regulation; cell population study; cell proliferation; developmental genetics; fluorescence microscopy; gastrointestinal system; gene induction /repression; gene mutation; genetic mapping; genetic regulation; genetic regulatory element; genetically modified animals; green fluorescent proteins; intermolecular interaction; invertebrate embryology; larva; molecular cloning; nucleic acid sequence; protein structure function; temperature sensitive mutant; transcription factor

A major challenge in cell-cycle research is to understand how cell division is regulated in concert with growth and differentiation during the development of complex organisms. Although substantial progress has been made in understanding ligand-induced signaling and cell-cycle regulation individually, it remains unclear how these processes are integrated in vivo to accomplish the proper timing of cell division during animal development. Genetic model systems have provided powerful means to address these questions. In this grant proposal, we describe genetic approaches in the nematode C. elegans aimed at identifying how developmental signals connect to the cell-cycle machinery during the G1 phase of the cell cycle. In preliminary studies, we have characterized G1 cell-cycle genes in C. elegans. These include positive regulators homologous to a D-type cyclin and a cdk4/6 kinase, and negative regulators related to the retinoblastoma (Rb) protein and the p21/p27 CIP/KIP family of CDK inhibitors. Our results indicate that G1 control in C. elegans follows molecular mechanisms that are closely related to those used in mammalian cells. In addition, we have isolated mutations that disturb cell division in specific lineages and developmental stages, likely defining genes that upstream of the cell-cycle machinery. Specific Aim 1 describes genetic screens aimed at identifying genes that act upstream of the basic cell-cycle machinery. Each of the screens has been tested and has already produced interesting candidate mutants. Mutations will be characterized, mapped and assigned to complementation groups. Molecular characterizations, described under specific Aim 2, will initially focus on three previously identified mutations. These mutations allow a subset of cells to divide during the second larval stage and appear to define a pathway for cell lineage dependent regulation of a CIP/KIP CDK inhibitor. These experiments will help reveal cell division-control mechanisms that are poorly understood yet highly important for our understanding of normal development as will as diseases as cancer.

细胞周期研究的一个主要挑战是了解如何在复杂生物体发展过程中与生长和分化一起调节细胞分裂。尽管在分别理解配体诱导的信号传导和细胞周期调节方面取得了重大进展，但尚不清楚这些过程如何在体内整合以完成动物发育过程中细胞分裂的适当时间。 遗传模型系统提供了解决这些问题的强大手段。 在该赠款建议中，我们描述了线虫秀丽隐杆线虫中的遗传方法，旨在确定在细胞周期的G1阶段，发育信号如何连接到细胞周期机械。在初步研究中，我们表征了秀丽隐杆线虫中的G1细胞周期基因。 其中包括与D型细胞周期蛋白和CDK4/6激酶同源的阳性调节剂，以及与视网膜细胞瘤（RB）蛋白和CDK抑制剂的P21/P27 CIP/KIP家族有关的负调节剂。 我们的结果表明，秀丽隐杆线虫中的G1控制遵循与哺乳动物细胞中使用的分子机制。 此外，我们还具有分离的突变，这些突变会干扰特定谱系和发育阶段的细胞分裂，这可能定义了细胞周期机械上游的基因。特定目标1描述了旨在识别基本细胞周期机械上游基因的遗传筛选。 每个屏幕都已进行了测试，并且已经产生了有趣的候选突变体。 突变将被表征，映射和分配给互补组。 在特定目标2中描述的分子特征最初将集中在三个先前鉴定的突变上。 这些突变使细胞的子集在第二个幼虫阶段分裂，并似乎定义了CIP/KIP CDK抑制剂的细胞谱系调节途径。这些实验将有助于揭示细胞分裂控制机制，这些机制知之甚少，但对于我们对正常发育和癌症的疾病的理解非常重要。