Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, United States.
Center for Biologics Evaluation and Research, FDA, Silver Spring, MD, United States.
Curr Opin Microbiol. 2019 Feb;47:74-81. doi: 10.1016/j.mib.2019.01.002. Epub 2019 Mar 11.
The BvgAS two-component system of Bordetella pertussis directly activates the expression of a large number of virulence genes in an environmentally responsive manner. The Bvg mode also promotes the expression of the phosphodiesterase BvgR, which turns off the expression of another set of genes, the vrgs, by reducing levels of c-di-GMP. Increased levels of c-di-GMP in the Bvg mode are required, together with the phosphorylated response regulator protein RisA∼P, to activate vrg expression. Phosphorylation of RisA requires RisK, a non-co-operonic sensor kinase, but not its co-operonic sensor kinase RisS which is truncated in B. pertussis but intact in the ancestral B. bronchiseptica. The loss of RisS during evolution of B. pertussis led to the ability to express the vrgs, potentially enhancing aerosol transmission of B. pertussis.
百日咳博德特氏菌的 BvgAS 双组分系统以环境响应的方式直接激活大量毒力基因的表达。Bvg 模式还促进磷酸二酯酶 BvgR 的表达，通过降低 c-di-GMP 的水平来关闭另一组基因 vrgs 的表达。Bvg 模式中 c-di-GMP 水平的增加，以及磷酸化反应调节蛋白 RisA∼P，共同激活 vrg 的表达。RisA 的磷酸化需要非协同性传感器激酶 RisK，但不需要其协同性传感器激酶 RisS，后者在百日咳博德特氏菌中被截断，但在原始的支气管败血波氏杆菌中完整。在百日咳博德特氏菌进化过程中，RisS 的缺失导致了 vrgs 的表达能力，可能增强了百日咳博德特氏菌的气溶胶传播能力。
