Thermal and Nutritional Regulation of Ribosome Hibernation in Staphylococcus aureus.
Thermal and Nutritional Regulation of Ribosome Hibernation in Staphylococcus aureus.
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DOI：
10.1128/jb.00426-18
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发表时间：
2018-12-15
影响因子：
3.2
通讯作者：
Yap MN
中科院分区：
文献类型：
--
作者：
Basu A;Shields KE;Eickhoff CS;Hoft DF;Yap MN
70S核糖体(100S复合体)的二聚化在人类主要病原体金黄色葡萄球菌的翻译调控和感染性中起着重要作用。尽管二聚化因子HPF已经被生化定性，但调节100s核糖体丰度的途径仍然难以捉摸。我们鉴定了一种代谢物和营养感应转录因子Cody，它在营养和温度依赖的方式下既是HPF表达的激活因子，也是HPF表达的抑制因子。此外，Cody介导的HPF的激活掩盖了来自一般应激反应SigB启动子的第二个HPF转录本。科迪和SigB调控一系列毒力基因。核糖体稳态和两个主要毒力调节因子之间意想不到的联系为替代可用药部位提供了新的机会。翻译沉默的100S核糖体是一种知之甚少的二聚体70S复合体，它在所有细菌门中普遍存在。在一些细菌中，冬眠的100S核糖体的消除会导致翻译去阻遏、核糖体不稳定、抗生素敏感性和生物膜缺陷。在菲米库特，如条件致病菌金黄色葡萄球菌，一种名为冬眠促进因子(HPF)的190个氨基酸的蛋白质通过HPF同源二聚体之间的直接相互作用二聚化并连接两个70年代的核糖体，每个HPF单体拴在一个单独的70年代复合体上。在伽马蛋白细菌和蓝藻中，100S核糖体的形成分别是在指数后生长阶段和黑暗阶段专一诱导的，而菲尔米特细菌的100S核糖体是从滞后对数期通过后稳定期结构性地产生的。对控制HPF表达和100s核糖体丰度的调控途径知之甚少。在这里，我们展示了一般应激反应(GSR)西格玛因子(SigB)和GTP感应转录因子(Cody)整合营养和热信号来调节金黄色葡萄球菌HPF的合成，导致在败血症感染的小鼠模型中病原体的毒力增强。对HPF的Cody依赖调节是菌株特有的。上位性分析进一步证明Cody以一种条件依赖的方式在GSR途径的上游发挥作用。这些结果揭示了金黄色葡萄球菌胁迫生理、核糖体代谢和感染生物学之间的重要联系。重要性70S核糖体(100S复合体)的二聚化在人类主要病原体金黄色葡萄球菌的翻译调控和感染性中起着重要作用。尽管二聚化因子HPF已经被生化定性，但调节100s核糖体丰度的途径仍然难以捉摸。我们鉴定了一种代谢物和营养感应转录因子Cody，它在营养和温度依赖的方式下既是HPF表达的激活因子，也是HPF表达的抑制因子。此外，Cody介导的HPF的激活掩盖了来自一般应激反应SigB启动子的第二个HPF转录本。科迪和SigB调控一系列毒力基因。核糖体稳态和两个主要毒力调节因子之间意想不到的联系为替代可用药部位提供了新的机会。
The dimerization of 70S ribosomes (100S complex) plays an important role in translational regulation and infectivity of the major human pathogen Staphylococcus aureus. Although the dimerizing factor HPF has been characterized biochemically, the pathways that regulate 100S ribosome abundance remain elusive. We identified a metabolite- and nutrient-sensing transcription factor, CodY, that serves both as an activator and a repressor of hpf expression in nutrient- and temperature-dependent manners. Furthermore, CodY-mediated activation of hpf masks a secondary hpf transcript derived from a general stress response SigB promoter. CodY and SigB regulate a repertoire of virulence genes. The unexpected link between ribosome homeostasis and the two master virulence regulators provides new opportunities for alternative druggable sites. The translationally silent 100S ribosome is a poorly understood form of the dimeric 70S complex that is ubiquitously found in all bacterial phyla. The elimination of the hibernating 100S ribosome leads to translational derepression, ribosome instability, antibiotic sensitivity, and biofilm defects in some bacteria. In Firmicutes, such as the opportunistic pathogen Staphylococcus aureus, a 190-amino acid protein called hibernating-promoting factor (HPF) dimerizes and conjoins two 70S ribosomes through a direct interaction between the HPF homodimer, with each HPF monomer tethered on an individual 70S complex. While the formation of the 100S ribosome in gammaproteobacteria and cyanobacteria is exclusively induced during postexponential growth phase and darkness, respectively, the 100S ribosomes in Firmicutes are constitutively produced from the lag-logarithmic phase through the post-stationary phase. Very little is known about the regulatory pathways that control hpf expression and 100S ribosome abundance. Here, we show that a general stress response (GSR) sigma factor (SigB) and a GTP-sensing transcription factor (CodY) integrate nutrient and thermal signals to regulate hpf synthesis in S. aureus, resulting in an enhanced virulence of the pathogen in a mouse model of septicemic infection. CodY-dependent regulation of hpf is strain specific. An epistasis analysis further demonstrated that CodY functions upstream of the GSR pathway in a condition-dependent manner. The results reveal an important link between S. aureus stress physiology, ribosome metabolism, and infection biology. IMPORTANCE The dimerization of 70S ribosomes (100S complex) plays an important role in translational regulation and infectivity of the major human pathogen Staphylococcus aureus. Although the dimerizing factor HPF has been characterized biochemically, the pathways that regulate 100S ribosome abundance remain elusive. We identified a metabolite- and nutrient-sensing transcription factor, CodY, that serves both as an activator and a repressor of hpf expression in nutrient- and temperature-dependent manners. Furthermore, CodY-mediated activation of hpf masks a secondary hpf transcript derived from a general stress response SigB promoter. CodY and SigB regulate a repertoire of virulence genes. The unexpected link between ribosome homeostasis and the two master virulence regulators provides new opportunities for alternative druggable sites.