REGULATION OF RETROTRANSPOSITION IN S CEREVISIAE

酿酒酵母逆转录转座的调控

• 批准号: 2459605
• 负责人: M Joan CURCIO
• 金额: $ 10.08万
• 依托单位: WADSWORTH CENTER
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2459605
• 关键词: Saccharomyces cerevisiae; endopeptidases; enzyme induction /repression; fungal genetics; gene complementation; gene expression; gene mutation; genetic transcription; reporter genes; transposon /insertion element

DESCRIPTION: The Ty1 elements of yeast are retrotransposons that encode structural proteins, protease, integrase, and reverse transcriptase. Like retroviruses, these products are formed by transcription of polycistronic messages and post-translational processing events such as protease cleavages and phosphorylation. Although Ty1 RNA represents a large fraction of total RNA in the cell, transposition events are rare, presumably due to a mechanism of regulation called transpositional dormancy. The main objective of this proposal is to identify and characterize the cellular genes involved in transpositional dormancy. These genes are identified by mutations that cause a hypertranspositional phenotype. The PI has used a novel reporter gene construct to screen for such mutations and at present over 160 mutations have been isolated. The initial focus will be on characterizing a subset of these which affect transposition at a post-transcriptional level rather than those mutations that increase Ty1 transcription rates. Genetic characterization of the mutants will include complementation test, dominance relationships, and several genetic and molecular screens to determine the level at which the mutation affects the transposition process. Selected genes will be cloned by complementation of the hypertranspositional phenotype. Steps in the formation of Ty1-like particles, such as protease activation (a rate-limiting step) and VLP formation will be studied in mutant and wild- type cells to identify new mechanisms of transpositional regulation.

描述：酵母的 Ty1 元件是逆转录转座子，编码 结构蛋白、蛋白酶、整合酶和逆转录酶。 与逆转录病毒一样，这些产物是通过转录形成的 多顺反子消息和翻译后处理事件，例如 蛋白酶裂解和磷酸化。 虽然 Ty1 RNA 代表 细胞中总RNA的很大一部分，转座事件很少见， 可能是由于一种称为转位的调节机制 休眠。 该提案的主要目标是确定并描述 参与转座休眠的细胞基因。 这些基因是 通过引起超转座表型的突变来识别。 这 PI 使用了一种新型报告基因构建体来筛选此类突变 目前已分离出160多个突变。 最初的焦点 将描述影响转置的这些子集的特征 在转录后水平而不是那些增加的突变 Ty1 转录率。 突变体的遗传特征将 包括互补测试、优势关系等 遗传和分子筛选以确定 突变影响转座过程。 选定的基因将是 通过超转座表型的互补进行克隆。 步骤 Ty1 样颗粒的形成，例如蛋白酶激活（a 限速步骤）和VLP形成将在突变体和野生型中进行研究 类型细胞以确定转座调节的新机制。