Laboratory of Biosystem Dynamics, Department of Signal Processing, Tampere University of Technology, 33101 Tampere, Finland.
FEBS Lett. 2012 Nov 2;586(21):3870-5. doi: 10.1016/j.febslet.2012.09.014. Epub 2012 Sep 24.
The kinetics of transcription initiation in Escherichia coli depend on the duration of two rate-limiting steps, the closed and the open complex formation. In a lac promoter variant, P(lac/ara-1), the kinetics of these steps is controlled by IPTG and arabinose. From in vivo single-RNA measurements, we find that induction affects the mean and normalized variance of the intervals between consecutive RNA productions. Transcript production is sub-Poissonian in all conditions tested. The kinetics of each step is independently controlled by a different inducer. We conclude that the regulatory mechanism of P(lac/ara-1) allows the stochasticity of gene expression to be environment-dependent.
大肠杆菌转录起始的动力学取决于两个限速步骤的持续时间，即封闭复合物和开放复合物的形成。在乳糖启动子变体 P(lac/ara-1)中，这些步骤的动力学受 IPTG 和阿拉伯糖的控制。通过体内单 RNA 测量，我们发现诱导会影响连续 RNA 产生之间间隔的平均值和标准化方差。在所有测试条件下，转录产物的产生都是亚泊松分布。每个步骤的动力学都由不同的诱导剂独立控制。我们得出的结论是，P(lac/ara-1)的调控机制允许基因表达的随机性依赖于环境。
