Control of the cell cycle by mRNA degradation.

通过 mRNA 降解控制细胞周期。

• 批准号: 6573711
• 负责人: MARK E SCHMITT
• 金额: $ 25.59万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6573711
• 关键词: biotransformation; cell cycle; chemical cleavage; cyclins; endoribonucleases; enzyme activity; enzyme substrate complex; gene deletion mutation; gene expression; genetic regulatory element; genetic transcription; genome; immunoprecipitation; messenger RNA; molecular cloning; nucleic acid purification; nucleic acid sequence; posttranslational modifications; protein localization; protein quantitation /detection; ribonucleoproteins

DESCRIPTION (provided by applicant): In recent years a tremendous amount of excitement has surrounded the finding that regulated proteolysis is intricately involved in controlling the cell cycle in yeast and mammals. We have found that regulated ribonuclease digestion also plays a crucial part in controlling the cell cycle in yeast. The major objective for this proposal is to determine the sites, mechanism and regulation of mRNA destabilization by the ribonucleoprotein endoribonuclease RNase MRP in late telophase of the cell division cycle. We have discovered that mutations of different components of the RNase MRP enzyme complex lead to a cell division cycle (CDC) arrest. Divided nuclei and an elongated spindle characterize this late cell cycle arrest, in which cells fail to disassemble their spindle or to undergo cytokinesis. This M to G1 arrest is classically defined by the CDC5, DBF2 group of mutations. These M to G1 mutants lead to the inability to turn off the Clb1&2/Cdc28 cyclin/kinase. Inactivation of the kinase is required for disassembly of the spindle, cytokinesis and the ability to enter G1. Results indicate that the cell division cycle arrest in RNase MRP mutants is the result of a failure to rapidly degrade the CLB2 mRNA. Increased CLB2 mRNA leads to increased CIb2 protein, associated kinase activity and cell cycle arrest. The specific goals during the project period will include characterizing the pathway of CLB2 mRNA degradation and determining direct targets of RNase MRP in addition to CLB2 mRNA. Genome technology will be used to identify all of the potential RNase MRP substrates in a cell. A series of biochemical and genetic analyses will identify instability elements and the direct sites of RNase MRP action. Lastly, we will investigate the regulation of RNase MRP during the cell cycle and determine the means of that regulation. The significance of the role of RNase MRP in the M to G1 transition cannot be overstated. Regulated degradation of specific mRNAs may play as large a part in cell cycle control as regulated proteolysis. Many of these late acting genes have human homologues (PTEN/MMAC1, PIk, Polo, p55CDC) that are intimately involved in regulating the cell cycle and cell proliferation. Humans also have an RNase MRP complex with RNA and protein subunits similar to the yeast enzyme. Mutations in human RNase MRP cause a pleotropic disease, Cartilage Hair Hypoplasia. The manifestations of this disease are caused by a general cell proliferation defect, similar to what we see in yeast. This will allow us to use a simple genetic model system to lend insights into human disease.

描述(申请人提供)：近年来，围绕着调控蛋白分解复杂地参与控制酵母和哺乳动物的细胞周期这一发现，人们激动不已。我们发现，受调控的核糖核酸酶消化在控制酵母细胞周期中也起着至关重要的作用。这项建议的主要目的是确定核糖核蛋白内切核酸酶RNase MRP在细胞分裂周期末期的mRNA失稳的位置、机制和调控。我们发现，RNase MRP酶复合体不同成分的突变会导致细胞分裂周期(CDC)停滞。分裂的细胞核和细长的纺锤体是这种晚期细胞周期停滞的特征，在这种情况下，细胞无法拆解其纺锤体或进行胞质分裂。CDC5和DBF2组突变经典地定义了这种从M到G1的停滞。这些从M到G1的突变导致不能关闭Clb1&2/CDc28细胞周期蛋白/激酶。该激酶的失活是纺锤体解体、胞质分裂和进入G1的能力所必需的。结果表明，RNase MRP突变体的细胞分裂周期停滞是未能迅速降解CLB2mRNA的结果。CLB2mRNA的增加导致CIB2蛋白的增加，相关的激酶活性和细胞周期停滞。项目期间的具体目标将包括描述CLB2 mRNA降解的途径，以及确定除CLB2 mRNA之外的RNase MRP的直接靶标。基因组技术将用于识别细胞中所有潜在的核糖核酸酶MRP底物。一系列生化和遗传分析将确定不稳定因素和核糖核酸酶MRP作用的直接位置。最后，我们将研究RNase MRP在细胞周期中的调节，并确定调节的方法。核糖核酸酶MRP在M向G1转变中的作用的重要性怎么强调都不为过。特定mRNAs的受控降解在细胞周期控制中的作用可能与受控蛋白分解一样重要。这些晚期作用基因中有许多与调节细胞周期和细胞增殖密切相关的人类同源基因(PTEN/MMAC1、PIK、Polo、p55CDC)。人类也有一个RNase MRP复合体，其RNA和蛋白质亚基类似于酵母酶。人类核糖核酸酶MRP的突变会导致一种多发性疾病，即软骨毛发发育不良。这种疾病的表现是由一种普遍的细胞增殖缺陷引起的，类似于我们在酵母中看到的。这将使我们能够使用简单的遗传模型系统来洞察人类疾病。