Yokoyama Fumiaki, Imai Tomoya, Aoki Wataru, Ueda Mitsuyoshi, Kawamoto Jun, Kurihara Tatsuo
Institute for Chemical Research, Kyoto University, Uji, Japan.
Research Institute for Sustainable Humanosphere, Kyoto University, Uji, Japan.
Front Microbiol. 2021 Feb 18;12:629023. doi: 10.3389/fmicb.2021.629023. eCollection 2021.
Bacteria secrete and utilize nanoparticles, called extracellular membrane vesicles (EMVs), for survival in their growing environments. Therefore, the amount and components of EMVs should be tuned in response to the environment. However, how bacteria regulate vesiculation in response to the extracellular environment remains largely unknown. In this study, we identified a putative sensor protein, HM1275, involved in the induction of vesicle production at high lysine concentration in a hypervesiculating Gram-negative bacterium, HM13. This protein was predicted to possess typical sensing and signaling domains of sensor proteins, such as methyl-accepting chemotaxis proteins. Comparison of vesicle production between the -disrupted mutant and the parent strain revealed that HM1275 is involved in lysine-induced hypervesiculation. Moreover, HM1275 has sequence similarity to a biofilm dispersion protein, BdlA, of PAO1, and disruption increased the amount of biofilm. Thus, this study showed that the induction of vesicle production and suppression of biofilm formation in response to lysine concentration are under the control of the same putative sensor protein.
细菌分泌并利用被称为细胞外膜泡（EMV）的纳米颗粒在其生长环境中生存。因此，EMV的数量和成分应根据环境进行调节。然而，细菌如何响应细胞外环境调节膜泡形成在很大程度上仍不清楚。在本研究中，我们在一种超膜泡化革兰氏阴性菌HM13中鉴定出一种假定的传感器蛋白HM1275，它在高赖氨酸浓度下参与诱导膜泡产生。该蛋白预计具有传感器蛋白的典型传感和信号结构域，如甲基接受趋化蛋白。-破坏突变体与亲本菌株之间膜泡产生的比较表明，HM1275参与赖氨酸诱导的超膜泡化。此外，HM1275与PAO1的生物膜分散蛋白BdlA具有序列相似性，破坏该蛋白会增加生物膜的数量。因此，本研究表明，响应赖氨酸浓度的膜泡产生诱导和生物膜形成抑制受同一假定传感器蛋白的控制。
