AbstractPseudomonas aeruginosa, a significant opportunistic pathogen, can participate in inter-species communication through signaling by cis-2-unsaturated fatty acids of the diffusible signal factor (DSF) family. Sensing these signals leads to altered biofilm formation and increased tolerance to various antibiotics, and requires the histidine kinase PA1396. Here, we show that the membrane-associated sensory input domain of PA1396 has five transmembrane helices, two of which are required for DSF sensing. DSF binding is associated with enhanced auto-phosphorylation of PA1396 incorporated into liposomes. Further, we examined the ability of synthetic DSF analogues to modulate or inhibit PA1396 activity. Several of these analogues block the ability of DSF to trigger auto-phosphorylation and gene expression, whereas others act as inverse agonists reducing biofilm formation and antibiotic tolerance, both in vitro and in murine infection models. These analogues may thus represent lead compounds to develop novel adjuvants improving the efficacy of existing antibiotics.
摘要:
铜绿假单胞菌是一种重要的机会性病原体,通过DSF家族的
-2-不饱和脂肪酸信号参与物种间通信。感知这些信号会导致生物膜形成的改变和对各种抗生素的耐受性增加,并且需要组氨酸激酶PA1396。在这里,我们展示了PA1396的膜相关感受输入结构域具有五个跨膜螺旋,其中两个是DSF感知所必需的。DSF结合与PA1396自体磷酸化增强有脂质体中的PA1396相关。此外,我们检查了合成DSF类似物调节或抑制PA1396活性的能力。其中几种类似物阻止DSF触发自体磷酸化和基因表达的能力,而其他类似物作为逆向激动剂减少生物膜形成和抗生素耐受性,无论是在体外还是在小鼠感染模型中。这些类似物可能代表了开发新型辅助剂的先导化合物,从而提高现有抗生素的有效性。