Glaser P, Sharpe M E, Raether B, Perego M, Ohlsen K, Errington J
Sir William Dunn School of Pathology, University of Oxford, UK.
Genes Dev. 1997 May 1;11(9):1160-8. doi: 10.1101/gad.11.9.1160.
The Bacillus subtilis spo0J gene is required for accurate chromosome partitioning during growth and sporulation. We have characterized the subcellular localization of Spo0J protein by immunofluorescence and, in living cells, by use of a spo0J-gfp fusion. We show that the Spo0J protein forms discrete stable foci usually located close to the cell poles. The foci replicate in concert with the initiation of new rounds of DNA replication, after which the daughter foci migrate apart inside the cell. This migration is independent of cell length extension, and presumably serves to direct the daughter chromosomes toward opposite poles of the cell, ready for division. During sporulation, the foci move to the extreme poles of the cell, where they function to position the oriC region of the chromosome ready for polar septation. These observations provide strong evidence for the existence of a dynamic, mitotic-like apparatus responsible for chromosome partitioning in bacteria.
枯草芽孢杆菌的spo0J基因是生长和孢子形成过程中准确进行染色体分配所必需的。我们通过免疫荧光以及在活细胞中使用spo0J - gfp融合蛋白来表征Spo0J蛋白的亚细胞定位。我们发现Spo0J蛋白形成离散的稳定焦点，通常位于靠近细胞极的位置。这些焦点与新一轮DNA复制的起始同步复制，之后子代焦点在细胞内分开迁移。这种迁移与细胞长度的延伸无关，推测其作用是将子代染色体导向细胞的相反两极，为细胞分裂做好准备。在孢子形成过程中，这些焦点移动到细胞的极端两极，在那里它们的作用是定位染色体的oriC区域，为极向隔膜形成做好准备。这些观察结果为细菌中存在负责染色体分配的动态、有丝分裂样机制提供了有力证据。
