转录因子DksA对细胞分裂产生相反的影响,取决于ppGpppp的存在
bioRxiv : the preprint server for biology
|June 9, 2023
概括
警报激素 (p)ppGpp通过影响转录因子DksA来调节细菌细胞分裂. 这一发现揭示了ppGpppp.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 细菌生理学 细菌生理学
背景情况:
- 细菌细胞的大小受到严格监管,受营养的可用性和细胞分裂时间的影响.
- 众所周知,警报激素 (p) ppGpp (ppGpp) 调解压力反应,但其在细胞分裂中的作用不明.
- 之前的研究表明,在大肠杆菌中ppGpp和细胞长度之间存在负相关性.
研究的目的:
- 系统地分析ppGpp对大肠杆菌细菌生长和细胞分裂的影响.
- 阐明ppGpp影响细胞分裂机制 (分裂体) 组装的机制.
- 研究ppGpp与转录因子DksA在调节细胞分裂中的相互作用.
主要方法:
- 对带有改变ppGpp合成或过度生产的大肠杆菌突变的分析.
- 使用热敏分裂突变体和光标记的分裂蛋白.
- 转录组分析以确定ppGpp和DksA的监管目标.
主要成果:
- 丢失ppGpp或DksA导致细胞平均长度增加,ppGpp突变显示有丝状细胞.
- 证实ppGpp和DksA是细胞分裂激活剂,主要通过间接的转录调节.
- DksA对缺乏ppGpp的细胞的分裂表现出抑制作用,这表明其作用取决于环境.
结论:
- ppGpp是细菌细胞分裂的一般调节者,即使在营养丰富的条件下也是必不可少的.
- ppGpp充当控制DksA在细胞分裂中的作用的开关,调节细胞长度.
- 了解这些调节机制可以为开发新的抗菌疗法提供信息.
相关概念视频
01:23Stringent Response in E. coli
32
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
32
01:27Molecular Factors Affecting Cell Division
3.2K
Several external and internal factors influence the initiation and inhibition of cell division. For instance, the death of nearby cells or the release of human growth hormone (hGH) promotes cell division. In contrast, lack of hGH or crowding of cells can inhibit cell division.
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
3.2K
01:23Negative Regulator Molecules
35.5K
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
35.5K
02:34Inhibition of Cdk Activity
4.8K
The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
4.8K
02:37DNA Damage can Stall the Cell Cycle
9.2K
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.2K
02:36Cells Coordinate Growth and Proliferation
4.5K
Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...
4.5K