Deletion of spoIIAB blocks endospore formation in Bacillus subtilis at an early stage.
Deletion of spoIIAB blocks endospore formation in Bacillus subtilis at an early stage.
复制标题
spoIIAB 的缺失会阻止枯草芽孢杆菌早期内生孢子的形成。
DOI：
10.1128/jb.173.21.6678-6685.1991
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发表时间：
1991
影响因子：
3.2
通讯作者：
MoranJr,CP
中科院分区：
文献类型：
--
作者：
Coppolecchia,R;DeGrazia,H;MoranJr,CP
在枯草芽孢杆菌内生孢子形成的早期阶段，细胞不对称地分成遵循不同发育路径的两个隔室。这两个区室中基因的差异表达部分地由区室特异性转录因子sigma G和sigma K的产生控制。目前还不清楚σ G积累是如何限制在两个分室之一，前孢子。然而，观察到sigma F指导sigma G的结构基因的转录，并且sigma F活性可以被基因spoIIAB的产物修饰，这使得我们研究spoIIAB在孢子形成期间的作用。我们已经分离出携带spoIIAB缺失等位基因的突变体。这些突变体的电子显微镜检查显示，这些突变阻断了孢子形成的早期阶段之前，分隔，并造成广泛的细胞裂解。spoIIAB缺失等位基因导致通常只在形成孢子的野生型细胞的前孢子隔室中表达的基因的过度表达，而这些等位基因降低了其他基因的表达，包括spoIIE，其在野生型细胞中在分隔前表达。这些观察结果证实，spoIIAB是必不可少的孢子形成和一致的模型，其中的产品spoIIAB发挥作用，在调节的时间和/或隔室特异性的σ F-和σ G-定向转录。
During an early stage of endospore formation in Bacillus subtilis, the cell divides asymmetrically into two compartments that follow different developmental paths. The differential expression of genes in these two compartments is controlled in part by the production of compartment-specific transcription factors, sigma G and sigma K. It is not known how sigma G accumulation is restricted to one of the two compartments, the forespore. However, the observations that sigma F directs transcription of the structural gene for sigma G and that sigma F activity can be modified by the product of a gene, spoIIAB, has led us to investigate the role of spoIIAB during sporulation. We have isolated mutants that carry deletion alleles of spoIIAB. Electron microscopic examination of these mutants revealed that these mutations blocked endospore formation at an early stage before septation and caused extensive cell lysis. The spoIIAB deletion alleles caused hyperexpression of genes that are normally expressed exclusively in the forespore compartments of sporulating wild-type cells, whereas these alleles reduced expression of other genes, including spoIIE, which is expressed before septation in wild-type cells. These observations confirm that spoIIAB is essential for sporulation and are consistent with models in which the product of spoIIAB plays a role in regulating the timing and/or compartment specificity of sigma F- and sigma G-directed transcription.