Yeast plasmid segregation: investigation of host/plasmid interactions

酵母质粒分离：宿主/质粒相互作用的研究

• 批准号: 155268-2011
• 负责人: Dobson, Melanie
• 金额: $ 2.91万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=476020
• 关键词: Yeast; plasmid; segregation; investigation; host

The 2µm circle is a high copy-number plasmid stably maintained in the nucleus of most strains of the bakers yeast, Saccharomyces cerevisiae. The 2µm circle is a "selfish" DNA, borrowing host machinery for its replication and segregation to ensure it is seldom lost when the host cell divides, while conferring no advantage to the host. We have identified sumoylation (modification of target proteins with a small ubiquitin-related protein called SUMO) as a host function that regulates plasmid segregation. Biochemical, molecular genetics, and cell biology approaches will be used to elucidate the link between sumoylation and plasmid maintenance and to identify and investigate other host proteins borrowed by the plasmid that enable its inheritance. Fluorescence microscopy will be used to investigate the effect of absence of host proteins identified in our studies on equal partitioning of the multiple plasmid copies at cell division and on plasmid localization within the nucleus. Our studies will also help identify the cellular process to which the identified host proteins contribute and reveal new functions for others. This project will determine how the 2µm circle interacts with other components of the nucleus to ensure its efficient segregation. Understanding how sumoylation and other host processes are exploited by the yeast plasmid may reveal how other genetic elements, such as viruses are maintained and help determine the essential role sumoylation plays in faithful segregation of chromosomes during cell division.

2µm的圆圈是一个高拷贝数的质粒，稳定地保存在大多数面包酵母（Saccharomyces cerevisiae）菌株的细胞核中。2微米的圆环是一个“自私的”DNA，它借用宿主的机制进行复制和分离，以确保它在宿主细胞分裂时很少丢失，同时不赋予宿主任何优势。我们已经确定SUMO化（用一种称为SUMO的小泛素相关蛋白修饰靶蛋白）作为调节质粒分离的宿主功能。生物化学，分子遗传学和细胞生物学方法将被用来阐明类小泛素化和质粒维持之间的联系，并确定和调查其他宿主蛋白质借用的质粒，使其遗传。荧光显微镜将用于研究在我们的研究中鉴定的宿主蛋白的不存在对细胞分裂时多个质粒拷贝的均等分配和对细胞核内质粒定位的影响。我们的研究还将有助于确定所确定的宿主蛋白质所贡献的细胞过程，并揭示其他蛋白质的新功能。该项目将确定2μm圆如何与核的其他成分相互作用，以确保其有效分离。了解sumoylation和其他宿主过程是如何被酵母质粒利用的，可以揭示其他遗传元件（如病毒）是如何维持的，并有助于确定sumoylation在细胞分裂期间染色体的忠实分离中所起的重要作用。