Narula Jatin, Kuchina Anna, Lee Dong-Yeon D, Fujita Masaya, Süel Gürol M, Igoshin Oleg A
Department of Bioengineering and Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA.
Division of Biological Sciences, UCSD, San Diego, CA 92093, USA.
Cell. 2015 Jul 16;162(2):328-337. doi: 10.1016/j.cell.2015.06.012. Epub 2015 Jul 9.
Genes encoding proteins in a common regulatory network are frequently located close to one another on the chromosome to facilitate co-regulation or couple gene expression to growth rate. Contrasting with these observations, here, we demonstrate a functional role for the arrangement of Bacillus subtilis sporulation network genes on opposite sides of the chromosome. We show that the arrangement of two sporulation network genes, one located close to the origin and the other close to the terminus, leads to a transient gene dosage imbalance during chromosome replication. This imbalance is detected by the sporulation network to produce cell-cycle coordinated pulses of the sporulation master regulator Spo0A∼P. This pulsed response allows cells to decide between sporulation and continued vegetative growth during each cell cycle spent in starvation. The simplicity of this coordination mechanism suggests that it may be widely applicable in a variety of gene regulatory and stress-response settings. VIDEO ABSTRACT.
在共同调控网络中编码蛋白质的基因常常在染色体上彼此相邻定位,以促进协同调控或将基因表达与生长速率相耦合。与这些观察结果形成对比的是,在这里,我们证明了枯草芽孢杆菌芽孢形成网络基因在染色体两侧的排列具有功能作用。我们表明,两个芽孢形成网络基因的排列,一个靠近染色体的起始端,另一个靠近末端,会在染色体复制过程中导致短暂的基因剂量失衡。这种失衡被芽孢形成网络检测到,从而产生芽孢形成主调节因子Spo0A∼P的细胞周期协调脉冲。这种脉冲响应使细胞能够在饥饿状态下度过的每个细胞周期中决定是进行芽孢形成还是继续营养生长。这种协调机制的简单性表明它可能广泛适用于各种基因调控和应激反应情况。视频摘要。