Redundancy in the periplasmic adaptor proteins AcrA and AcrE provides resilience and an ability to export substrates of multidrug efflux.
Redundancy in the periplasmic adaptor proteins AcrA and AcrE provides resilience and an ability to export substrates of multidrug efflux.
复制标题
周质衔接蛋白 AcrA 和 AcrE 中的冗余提供了弹性和输出多药物流出底物的能力。
DOI：
10.1093/jac/dkt481
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Jessica M. A. Blair
中科院分区：
文献类型：
--
作者：
Helen E. Smith;Jessica M. A. Blair
目标
AcrAB-TolC外排泵的组件作为三重外排系统发挥作用，赋予对多种抗生素的耐药性，单个组件也可以与其他外排泵一起发挥作用。本研究旨在确定同源周质衔接蛋白（PAPs）AcrA和AcrE之间是否存在冗余，并测量这种冗余对抗菌素耐药性和抑制剂分子的潜在功效的影响。
方法
acrE基因在鼠伤寒沙门氏菌SL 1344和ΔacrA突变体中通过插入aph基因而失活。用携带acrA或acrE的质粒补充突变体。测定突变体对各种抗菌剂的抗菌敏感性，并测量各种底物的积累或流出。
结果
acrE单独失活没有表型效应。然而，PAPs失活的效果是加性的; acrA acrE突变体对某些抗菌剂更敏感，并且比单个acrA，acrE或acrB突变体积累更多的Hoechst染料。此外，双突变体侵袭人肠上皮细胞较差。acrA acrE突变体的表型缺陷得到改善的acrA或acrE的表达，但蛋白质表现出一定的底物特异性。
结论
这些数据首次显示了PAP AcrA和AcrE之间的冗余水平，并强调PAP是可用于增强临床抗菌剂作用的抑制剂分子的优良靶标。然而，AcrA和AcrE之间存在的冗余意味着潜在的抑制剂必须同时作用于两个靶标才能有效。
OBJECTIVES
The components of the AcrAB-TolC efflux pump function as a tripartite efflux system conferring resistance to multiple antibiotics and the individual components can also function in conjunction with other efflux pumps. This study aimed to establish whether redundancy exists between the homologous periplasmic adaptor proteins (PAPs) AcrA and AcrE and to measure the impact of this redundancy on antimicrobial resistance and the potential efficacy of inhibitor molecules.
METHODS
The acrE gene was inactivated in Salmonella enterica serovar Typhimurium SL1344 and a ΔacrA mutant by insertion of the aph gene. The mutants were complemented with plasmids carrying acrA or acrE. The antimicrobial susceptibility of the mutants to various antimicrobials was determined and the accumulation or efflux of various substrates was measured.
RESULTS
Inactivation of acrE alone had no phenotypic effect. However, the effect of inactivation of PAPs was additive; the acrA acrE mutant was more susceptible to certain antimicrobials and accumulated more Hoechst dye than single acrA, acrE or acrB mutants. In addition, the double mutant invaded human intestinal epithelial cells poorly. The phenotypic defects of the acrA acrE mutant were ameliorated by expression of either acrA or acrE, but the proteins exhibited some substrate specificity.
CONCLUSIONS
These data show for the first time the level of redundancy between the PAPs AcrA and AcrE, and highlight the PAPs as excellent targets for inhibitor molecules that could be used to potentiate the action of clinical antimicrobials. However, the redundancy that exists between AcrA and AcrE means potential inhibitors must act on both targets to be effective.
影响因子：
5.7
作者：
Mikolosko, J;Bobyk, K;Ghosh, P
通讯作者：
Ghosh, P
影响因子：
5.2
作者：
Coldham, Nick G.;Webber, Mark;Piddock, Laura J. V.
通讯作者：
Piddock, Laura J. V.
影响因子：
5.6
作者：
Zgurskaya, HI;Nikaido, H
通讯作者：
Nikaido, H