Control of rRNA expression by small molecules is dynamic and nonredundant
Control of rRNA expression by small molecules is dynamic and nonredundant
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DOI：
10.1016/s1097-2765(03)00266-1
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发表时间：
2003-07-01
期刊：
影响因子：
16
通讯作者：
Gourse, RL
中科院分区：
文献类型：
--
作者：
Murray, HD;Schneider, DA;Gourse, RL
核糖体RNA转录的控制是分子微生物学中最持久的问题之一，50多年来一直受到严格的审查。rRNA表达的快速变化发生在细菌生长周期的过渡期间和指数生长期间的营养变化之后。遗传方法和起始核苷三磷酸（iNTP）和鸟苷5 '-二磷酸，3'-二磷酸（ppGpp）浓度和rRNA启动子活性的测量表明，iNTP和ppGpp浓度的快速变化导致rRNA表达的快速变化。这两个调节信号是非冗余的：iNTP浓度的变化在从稳定期的生长期间主导调节，而ppGpp浓度的变化负责在指数期期间上调和下调后的调节。结果表明，使用两种稳态调节机制来监测核糖体活性的不同方面的分子逻辑，并提供重叠的调节回路的性质的一般见解。
The control of ribosomal RNA transcription is one of the most enduring issues in molecular microbiology, having been subjected to intense scrutiny for over 50 years. Rapid changes in rRNA expression occur during transitions in the bacterial growth cycle and following nutritional shifts during exponential growth. Genetic approaches and measurements of initiating nucleoside triphosphate (iNTP) and guanosine 5'-diphosphate, 3'-diphosphate (ppGpp) concentrations and of rRNA promoter activities showed that rapid changes in the concentrations of iNTPs and ppGpp account for the rapid changes in rRNA expression. The two regulatory signals are nonredundant: changes in iNTP concentration dominate regulation during outgrowth from stationary phase, whereas changes in ppGpp concentration are responsible for regulation following upshifts and downshifts during exponential phase. The results suggest a molecular logic for the use of two homeostatic regulatory mechanisms to monitor different aspects of ribosome activity and provide general insights into the nature of overlapping regulatory circuits.