Molecular Mechanisms of Cell Cycle Control

摘要 细胞分裂周期中的调节进程对于细胞忠实地生长和分裂至关重要。当单元格 周期控制被打乱，细胞可能获得突变或无法控制地增殖，这可能导致 癌症等疾病的发展。为了确保细胞准确复制和分裂，多个 重叠机制起到协调和排序细胞周期事件的作用。我的实验室的重点是 了解细胞周期调控转录、磷酸化和泛素介导的蛋白质降解 它们整合在一起，形成了一个强大的细胞周期调控网络。为了实现这一点，我们利用 在芽殖酵母中的高通量遗传方法，以揭示 扰乱细胞周期调控基因。在这项提案中，我们将重点关注三个关键的悬而未决的问题。第一, 细胞周期调节转录因子(TF)的磷酸化如何有助于细胞周期控制？ 我们将利用与磷缺乏的Tf等位基因的遗传互作筛选来阐明 磷酸化并检验转铁蛋白磷酸化对协调生长和能量的重要性的假说 生产与细胞周期有关。第二，应激反应通路如何协同调节细胞周期。 对环境压力的反应？我们将剖析守恒应力之间的串扰机制 反应途径，并研究这种串扰对细胞周期停滞和存活的重要性 对不同的环境应激源做出反应。第三，去泛素酶(DUB)如何调节 细胞周期调节蛋白的稳定性？我们将使用我们开发的一种方法来识别Dub 底物，以研究这些酶的体内功能和它们控制 细胞周期。通过回答这些问题，我们将开发一个网络级别的观点，了解转录和 蛋白质分解协调细胞周期事件，以确保细胞的忠实分裂。考虑到强守恒性， 酵母和人类细胞中的细胞周期调节机制，我们预计这项工作将为深入了解 细胞周期控制网络的中断如何导致疾病。

ABSTRACT Regulated progression through the cell division cycle is critical for cells to faithfully grow and divide. When cell cycle control is disrupted, cells can acquire mutations or proliferate uncontrollably, and this can lead to the development of diseases such as cancer. To ensure that cells replicate and divide accurately, multiple overlapping mechanisms function to coordinate and order cell cycle events. The focus of my laboratory is to understand how cell cycle-regulated transcription, phosphorylation and ubiquitin-mediated protein degradation are integrated to generate a robust cell cycle-regulatory network. To accomplish this we take advantage of high-throughput genetic approaches in budding yeast to uncover the systems-level consequences of perturbing cell cycle-regulatory genes. In this proposal we will focus on three key unanswered questions. First, how does phosphorylation of cell cycle-regulatory transcription factors (TFs) contribute to cell cycle control? We will utilize genetic interaction screens with phosphodeficient TF alleles to elucidate the importance of phosphorylation and test the hypothesis that TF phosphorylation is important to coordinate growth and energy production with the cell cycle. Second, how do stress response pathways cooperate to regulate the cell cycle in response to environmental stress? We will dissect the mechanism of crosstalk between conserved stress response pathways and investigate the importance of this crosstalk for cell cycle arrest and survival in response to distinct environmental stressors. Third, how do deubiquitinating enzymes (DUBs) regulate the stabilities of cell cycle-regulatory proteins? We will utilize an approach that we developed for identifying DUB substrates to investigate the in vivo functions of these enzymes and the mechanisms by which they control the cell cycle. By answering these questions, we will develop a network-level view of how transcription and proteolysis coordinate cell cycle events to ensure faithful cell division. Given the strong conservation between the cell cycle-regulatory mechanisms in yeast and human cells, we anticipate this work will provide insight into how disruptions in the cell cycle control network contribute to disease.