The CDK Activation Network of Fission Yeast

裂殖酵母的CDK激活网络

• 批准号: 7525139
• 负责人: ROBERT P FISHER
• 金额: $ 24.84万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2009-01-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7525139
• 关键词: Animal Model; Binding; Biochemical Genetics; Biological Models; Bypass; CDC2 Protein Kinase; Cell Cycle; Cell Proliferation; Cell division; Cells; Chemicals; Complex; Condition; Coupling; Cyclin-Dependent Kinases; Cyclins; DNA Damage; DNA Repair; Defect; Dependency; Engineering; Ensure; Enzymes; Eukaryota; Eukaryotic Cell; Event; Fission Yeast; Gene Expression; Genes; Genetic; Genetic Transcription; Genome; Genomics; Goals; Growth; Hand; Homologous Gene; Human; In Vitro; Laboratories; Link; Logic; Maintenance; Malignant Neoplasms; Mammals; Measures; Mediating; Medical Surveillance; Messenger RNA; Methyltransferase; Modeling; Normal tissue morphology; Organism; Orthologous Gene; Pathway interactions; Pattern; Phosphorylation; Phosphotransferases; Play; Polymerase; Positive Transcriptional Elongation Factor B; Process; Proteins; Public Health; Quality Control; RNA Polymerase II; RNA chemical synthesis; Refractory; Research; Resistance; Role; Saccharomyces cerevisiae; Saccharomycetales; Signal Transduction; Testing; Toxic effect; Transcript; Transcription Elongation; Translating; Work; analog; chemical genetics; cyclin H; design; homologous recombination; in vivo; inhibitor/antagonist; mRNA capping; mutant; neoplastic cell; novel; programs; response; small molecule; tool; transcription factor TFIIH; tumor progression; upstream kinase

DESCRIPTION (provided by applicant): The long-term goal of the proposed research is to understand how a network of cyclindependent kinases (CDKs) and upstream CDK-activating kinases (CAKs) coordinates cell division with gene expression and the maintenance of genome integrity in a model eukaryotic organism, the fission yeast Schizosaccharomyces pombe. In fission yeast, as in multicellular organisms, one kinase activates the major cell-cycle CDK (Cdk1) to drive cell division and phosphorylates RNA polymerase II to regulate the transcription cycle. That enzyme-Mcs6, which is homologous to human Cdk7-works together with another CDK, Cdk9, to control gene expression programs linked to the cell cycle, and to coordinate synthesis of RNA molecules with their processing to produce mature messenger RNAs (mRNAs) that can be translated into proteins. S. pombe also contains a second CAK, Csk1, which is dispensable for viability, but which activates Cdk1, Mcs6 and Cdk9. Cells lacking Csk1 have growth defects and are hypersensitive to DNA-damaging agents and replication inhibitors. The CAK-CDK network therefore signals through multiple pathways, and plays critical regulatory roles in gene expression and genomic surveillance, in addition to its canonical function in promoting cell proliferation. We will combine biochemical and genetic approaches to dissect the functions and targets of the CAK-CDK network in fission yeast. By introducing a genetically engineered version of each CDK that is susceptible to inhibition by a specially designed small molecule, we are able to switch kinase activity off in vivo, and measure the consequences for cell proliferation and gene expression. The same manipulation also allows us to identify the protein substrates of the targeted kinase. The specific aims are: 1. To investigate coordination between Mcs6 (Cdk7) and Cdk9, which act sequentially and in concert to control expression of select genes. We will investigate whether Cdk9 recruitment or activity in transcription elongation complexes depends on prior function of Mcs6. 2. To investigate the coupling of transcription (synthesis) of mRNAs with their maturation by a complex containing Cdk9 and an essential mRNA-processing enzyme, the mRNA 5'-cap methyltransferase Pcm1. 3. To identify new targets and functions of CAKs and CDKs in the DNA damage response. PUBLIC HEALTH RELEVANCE: The integrating function of the CAK-CDK network is conserved in human cells, and potentially disrupted in cancer, where impaired control of cell proliferation, derangement of gene expression and damage to the genome all contribute to the initiation and progression of tumors. If we are to block or inhibit functions of this pathway in order to stop growth and division of tumor cells, an understanding of its multiple functions will be needed to avoid toxicity to normal tissue. The powerful genetic tools available in fission yeast, and the fundamental conservation of pathway function and organization with humans, make S. pombe the ideal model system in which to perform this work.

描述（由申请人提供）：拟议的研究的长期目标是了解环依赖性激酶（CDKS）和上游CDK激活激酶（CAKS）网络如何与基因表达和维持基因组完整性在模型真核生物中的基因组完整性相协调。在裂变酵母中，与多细胞生物一样，一种激酶激活了主要的细胞周期CDK（CDK1），以驱动细胞分裂并磷酸化RNA聚合酶II以调节转录周期。该酶-MCS6与人CDK7-works同源，以及另一个CDK CDK9，以控制与细胞周期相关的基因表达程序，并协调RNA分子的合成与其处理以产生可以转化为蛋白质的成熟的Messenger RNA（mRNA）。 S. Pombe还包含第二个CAK，CSK1，该CSK1可用于生存能力，但激活CDK1，MCS6和CDK9。缺乏CSK1的细胞具有生长缺陷，对DNA损害剂和复制抑制剂的过敏性过敏。因此，CAK-CDK网络通过多种途径发出信号，除了其在促进细胞增殖方面的规范功能外，在基因表达和基因组监测中扮演关键的调节作用。我们将结合生化和遗传方法，以剖析裂变酵母中CAK-CDK网络的功能和靶标。通过引入每个CDK的基因工程版本，该版本易受特殊设计的小分子抑制的抑制作用，我们能够在体内关闭激酶活性，并测量细胞增殖和基因表达的后果。相同的操作还使我们能够鉴定靶激酶的蛋白质底物。具体目的是： 1。研究MCS6（CDK7）和CDK9之间的协调 控制选定基因表达的音乐会。我们将调查CDK9招聘还是 转录伸长复合物中的活性取决于MCS6的先验功能。 2。研究mRNA的转录（合成）与它们成熟的偶联 含有CDK9和必需mRNA处理酶的复合物，mRNA 5'-CAP 甲基转移酶PCM1。 3。确定在DNA损伤响应中CAKS和CDK的新目标和功能。 公共卫生相关性：CAK-CDK网络的综合功能在人类细胞中保守，并可能在癌症中破坏，在癌症中，控制细胞增殖的控制受损，基因表达的危险和对基因组的损害都有助于肿瘤的起始和进展。如果我们要阻止或抑制该途径的功能以阻止肿瘤细胞的生长和分裂，则需要了解其多种功能，以避免对正常组织的毒性。裂变酵母中可用的强大遗传工具，以及与人类的途径功能和组织的基本保护，使S. Pombe成为执行这项工作的理想模型系统。