Yao Shiyin, Toukdarian Aresa, Helinski Donald R
Center for Molecular Genetics and Division of Biological Sciences, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0322, USA.
Plasmid. 2006 Sep;56(2):124-32. doi: 10.1016/j.plasmid.2006.04.003. Epub 2006 Jun 13.
Multi-copy plasmids in Escherichia coli are not randomly distributed throughout the cell but are present as clusters of plasmid molecules that are localized at preferred cellular locations. A plasmid RK2 derivative (pZZ15) that can be tagged with a green fluorescent protein-LacI fusion protein normally exists as clusters that are localized at the mid- and quarter-cell positions. In this study the effect of the protein synthesis inhibitor, chloramphenicol, and the RNA synthesis inhibitor, rifampicin, on RK2 clustering and localization was examined. The addition of either inhibitor to exponentially growing E. coli cells carrying pZZ15 results in a displacement of the position and a declustering of this multi-copy plasmid indicating that continued protein synthesis and RNA synthesis are required for clustering and localization of this plasmid. It is likely that it is not just the process of transcription or translation that is important for clustering but rather some host or plasmid encoded factor(s) that is required.
大肠杆菌中的多拷贝质粒并非随机分布于整个细胞，而是以质粒分子簇的形式存在，这些分子簇定位于细胞内特定的位置。一种可与绿色荧光蛋白-LacI融合蛋白标记的质粒RK2衍生物（pZZ15）通常以定位于细胞中部和四分之一处的簇的形式存在。在本研究中，研究了蛋白质合成抑制剂氯霉素和RNA合成抑制剂利福平对RK2聚集和定位的影响。将任何一种抑制剂添加到携带pZZ15的指数生长期大肠杆菌细胞中，都会导致该多拷贝质粒的位置发生移位和去簇化，这表明该质粒的聚集和定位需要持续的蛋白质合成和RNA合成。对于聚集来说，可能不仅仅是转录或翻译过程重要，而是需要一些宿主或质粒编码的因子。
