Cell Cycle Regulation of the Yeast HO Gene

酵母 HO 基因的细胞周期调控

• 批准号: 6892162
• 负责人: LINDA L. BREEDEN
• 金额: $ 54.92万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-12-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6892162
• 关键词: DNA binding protein; DNA damage; DNA replication; Saccharomyces cerevisiae; cell cycle; cell cycle proteins; cell growth regulation; cell proliferation; cyclins; fungal genetics; gene environment interaction; gene expression; gene induction /repression; genetic promoter element; genetic regulatory element; genetic transcription; immunoprecipitation; microarray technology; nucleic acid sequence; nutrition; phosphorylation; posttranslational modifications; protein binding

DESCRIPTION (provided by applicant): The mechanisms that control the cell cycle are remarkably conserved among all eukaryotes. Both mammals and budding yeast commit to another round of cell division during G1. Oncogenic processes exert their greatest impact by interfering with regulators of G1 progression. We propose to investigate the molecular mechanisms which control G1 progression in budding yeast. Our experiments are designed to determine how commitment to the budding yeast cell cycle is regulated in response to nutritional shifts, cell growth and adversities, such as DNA damage. In yeast, as in all higher eukaryotes, cell cycle transitions are governed by cyclin-dependent kinases (Cdks). Nine cyclins have been identified that bind and activate the Cdk of budding yeast (Cdc28). Three cyclins Cln1, Cln2 and Cln3 play critical roles in modulating the G1 to S transition. Our focus is upon determining what controls the expression of these three cyclins during G1. ECB elements activate transcription of CLN3 and other key cell cycle regulators at the M/G1 boundary. Two other promoter elements have been identified that are activated during G1 by Swi4/Swi6 and/or Mbpl/Swi6. These complexes activate transcription of many genes including CLN1 and CLN2, which are rate limiting for the transition to S phase. Our goal is to understand how internal and external signals modulate the activity of these transcription complexes and control the transition to S phase. We have identified one activator and two repressors that influence ECB activity. We will use genetic and biochemical strategies to determine how cell cycle regulation of transcription is conferred by these elements. We will also investigate the regulatory role of Swi6 in activating transcription in G1 and inhibiting transcription in response to DNA damage. We have identified sites at which Rad53 kinase phosphorylates Swi6 in response to DNA damage. We will determine the significance of these phosphorylations to the G1 DNA damage checkpoint. We will also determine whether the consensus site for Rad53 phosphorylation that we draw from our studies enables us to predict the sites at which Rad53 modifies other known targets.

描述（由申请人提供）：控制细胞周期的机制在所有真核生物中都非常保守。哺乳动物和出芽酵母都在G1期进行另一轮细胞分裂。致癌过程通过干扰G1进程的调节因子发挥其最大的影响。我们建议研究控制出芽酵母G1进程的分子机制。我们的实验旨在确定在营养变化、细胞生长和逆境（如DNA损伤）的影响下，芽殖酵母细胞周期是如何被调节的。在酵母中，与所有高等真核生物一样，细胞周期转变是由周期蛋白依赖性激酶（Cdks）控制的。已经鉴定出9种细胞周期蛋白结合并激活出芽酵母的Cdk （Cdc28）。三个细胞周期蛋白Cln1， Cln2和Cln3在G1到S的转变中起关键作用。我们的重点是确定在G1期间是什么控制了这三种细胞周期蛋白的表达。ECB元件在M/G1边界激活CLN3和其他关键细胞周期调节因子的转录。另外两个启动子元件已被确定在G1期间被Swi4/Swi6和/或Mbpl/Swi6激活。这些复合物激活包括CLN1和CLN2在内的许多基因的转录，这些基因是过渡到S期的限速基因。我们的目标是了解内部和外部信号如何调节这些转录复合物的活性并控制向S期的过渡。我们已经确定了影响欧洲央行活动的一个激活剂和两个抑制剂。我们将使用遗传和生化策略来确定细胞周期的转录调控是如何由这些元素赋予的。我们还将研究Swi6在G1期激活转录和抑制转录以响应DNA损伤中的调节作用。我们已经确定了Rad53激酶在DNA损伤时磷酸化Swi6的位点。我们将确定这些磷酸化对G1 DNA损伤检查点的重要性。我们还将确定我们从研究中得出的Rad53磷酸化的共识位点是否使我们能够预测Rad53修饰其他已知靶标的位点。