Molecular Genetic Analysis of Regulatory Networks Governing Cytokinesis

实验室内的研究集中在成功完成真核生物模式裂殖酵母胞质分裂所需的调控网络上。虽然该领域以前的工作主要集中在细胞骨架结构和在理想条件下生长的细胞中导致分裂所需的力上，但我们的目标是更好地了解当细胞受到阻碍细胞分裂过程的压力时，防止细胞质分裂失败所需的遗传调控网络。目前这项提议的基础源于最近支持细胞质分裂“监测系统”存在的工作。在细胞分裂机制的干扰下，该系统既具有延缓细胞周期进程的能力，又具有稳定细胞动力肌球蛋白环的能力。这些机制的生物学重要性已经得到证实，证明了四倍体中间体(在细胞质分裂失败时产生)显着增加了肿瘤发生的潜力。因此，对这些网络的理解有可能为真核生物维持基因组完整性的重要机制提供洞察力。目前的建议围绕着对以前未确定的调控网络的分子和遗传分析，这是胞质分裂监测系统正常功能和/或调节所必需的。这些途径是通过执行最近的全基因组筛查来确定的，该筛查测试了分裂酵母基因缺失突变体对Latrunculin A(一种肌动蛋白解聚药物，用作扰乱细胞分裂机制的工具)的超敏反应。正如预期的那样，这一筛选确定了许多在细胞骨架动力学和/或胞质分裂调节中起作用的基因。此外，还鉴定了许多其他意想不到的“命中”，识别影响生物过程的基因，如压力依赖信号、组蛋白乙酰化/去乙酰化和转录控制。利用实验室在分子生物学、遗传分析和荧光显微镜方面的专业知识，我们的目标是确定已识别的调控复合体的特征，以便提供模型真核细胞忠实和可靠地执行胞质分裂所需的遗传调控网络和分子机制的全面、全基因组图像。

Research within the lab focuses on the regulatory networks required to bring about the successful completion of cytokinesis in the model eukaryote, Schizosaccharomyces pombe. While previous work in the field has centered on the cytoskeletal structures and forces required to bring about cleavage in cells grown under ideal conditions, our goals are to better understand the genetic regulatory networks required to prevent cytokinesis failure when cells are subject to stresses that impede the cell division process. The foundation of the current proposal stems from recent work supporting the existence of a cytokinesis "monitoring system". Upon perturbation of the cell division machinery, this system has the capacity to both delay cell cycle progression and stabilize the cytokinetic actomyosin ring. The biological importance of such mechanisms have been substantiated by the demonstration that tetraploid intermediates (produced upon cytokinesis failure) show a markedly increased potential for tumourigenesis. Thus, an understanding of these networks has the potential to provide insight into the mechanisms important for maintaining genomic integrity in eukaryotes. The current proposal revolves around the molecular and genetic analysis of previously uncharacterized regulatory networks required for the proper function and/or regulation of the cytokinesis monitoring system. These pathways were identified through the execution of a recent genome-wide screen that assayed fission yeast gene deletion mutants for hypersensitivity to Latrunculin A (an actin depolymerizing drug used as a tool to perturb the cell division machinery). As expected this screen identified many genes with roles in the regulation of cytoskeletal dynamics and/or cytokinesis. In addition, many other unexpected "hits", identifying genes affecting biological processes such as stress-dependent signaling, histone acetylation/de-acetylation, and transcriptional control were also identified. Using the lab's expertise in molecular biology, genetic analysis, and fluorescence microscopy, our objectives are to characterize the identified regulatory complexes in order to provide a comprehensive, genome-wide picture of the genetic regulatory wiring and molecular mechanisms required by a model eukaryotic cell to faithfully and reliably execute cytokinesis.