CodY通过调节 Staphylococcus aureus 中的分支链脂肪酸合成来控制 SaeR/S 两组系统
Shahad Alqahtani1, Dennis A DiMaggio1, Shaun R Brinsmade1
1Department of Biology, Georgetown University, Washington, DC, USA.
Journal of bacteriology
|October 9, 2024
概括
黄金葡萄球菌的毒性是由CodY控制的,它将营养素的可用性与细菌防御机制联系起来. CodY通过调节分支链脂肪酸 (BCFA) 合成来调节SaeS传感器激酶活性,影响毒性因子的产生.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 细菌病原体的产生
背景情况:
- 金黄色葡萄球菌 (Staphylococcus aureus) 是一种主要的人类病原体,引起各种感染.
- 细菌的毒性受到CodY等因素的严格调节,该因素将营养状况与毒性基因表达联系起来.
- 以前已经观察到CodY通过分支链脂肪酸 (BCFA) 间接调节SaeRS双组分系统 (TCS),但其机制不清楚.
研究的目的:
- 阐明CodY调节Staphylococcus aureus中SaeRS TCS活动的机制.
- 研究分支链脂肪酸 (BCFA) 合成在CodY介导的毒性控制中的作用.
- 为了确定营养的可用性如何影响BCFA水平和随后的SaeS传感器激酶活性.
主要方法:
- 对金黄色葡萄球菌菌株的基因操纵,包括产生 codY null 突变体.
- 对基因表达的分析,包括ilv-leu和brnQ2.2等操作子.
- 膜分支链脂肪酸 (BCFA) 的量化.
- 检测SAE-依赖的促进剂活性和SAER酸化水平.
主要成果:
- 对SaeS传感器激酶活性的CodY依赖调节需要BCFA合成.
- 在营养充足期间,CodY通过降低ilv-leu操作子和brnQ2.2的调节来抑制BCFA合成.
- 在一个codY突变体中,ilv-leu和brnQ2的去抑制可提高BCFA前体合成的调节.
- 单独过度表达brnQ2会增加膜BCFA,SAE促进体活性和SAER酸化.
结论:
- CodY通过调节嵌入到膜中的anteroiso分支链氨基酸水平来控制SaeS传感器激酶活性.
- 这种机制将细菌的新陈代谢和生理与黄金葡萄球菌的毒性调节联系在一起.
- 了解这种途径为金黄色细菌感染提供了潜在的治疗点.
相关概念视频
Global Regulatory Systems
2
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
2
Bacterial Signaling
31.6K
Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
31.6K
Biosynthesis in Bacteria
1
Biosynthesis in bacteria is a fundamental anabolic process that generates essential macromolecules, including proteins, nucleic acids, lipids, and polysaccharides. These macromolecules are critical for cellular growth, replication, and function. The process is tightly regulated and energetically linked to catabolic pathways to ensure optimal resource utilization.Biosynthetic pathways begin with precursor metabolites such as pyruvate, acetyl-CoA, and glucose-6-phosphate derived from glycolysis,...
1
Gene Regulation in Microbial Communities: Quorum Sensing
3
Quorum sensing is a mechanism of bacterial communication that enables coordinated gene expression in response to changes in population density. This facilitates collective behaviors that enhance survival, resource acquisition, and ecological adaptation. This process relies on small signaling molecules called autoinducers that accumulate as bacterial populations grow. When a critical threshold concentration of autoinducers is reached, bacterial cells collectively modify gene expression,...
3
Prokaryotic Transcriptional Activators and Repressors
20.8K
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
20.8K
Gram-negative Bacterial Protein Secretion Systems
1
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
1


