PptAB Exports Rgg Quorum-Sensing Peptides in Streptococcus
PptAB Exports Rgg Quorum-Sensing Peptides in Streptococcus
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DOI：
10.1371/journal.pone.0168461
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发表时间：
2016-12-19
期刊：
影响因子：
3.7
通讯作者：
Federle, Michael J.
中科院分区：
文献类型：
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作者：
Chang, Jennifer C.;Federle, Michael J.
转座子诱变筛选被设计用于鉴定在化脓链球菌中Rgg 2/Rgg 3途径的肽-信息素信号传导中有缺陷的突变体，其在16个基因座中产生插入，显示降低的报道活性。14个独特的转座子插入映射到pptAB，ABC型转运最近描述出口粪肠球菌性信息素。与PptAB输出信号肽的想法一致，在所产生的pptAB缺失突变体的无细胞培养上清液中不再检测到被称为SHP（短疏水肽）的信息素。PptAB输出蛋白在厚壁菌门中是保守的，但其功能和底物仍不清楚。因此，我们测试了在变形链球菌中产生的pptAB突变体，发现尽管异源表达的SHP肽的分泌需要PptAB，但变形链球菌的分泌需要PptAB。变形杆菌内源性信息素XIP（sigX诱导肽）仅被部分破坏，表明存在XIP的次级分泌途径。
A transposon mutagenesis screen designed to identify mutants that were defective in peptide- pheromone signaling of the Rgg2/Rgg3 pathway in Streptococcus pyogenes generated insertions in sixteen loci displaying diminished reporter activity. Fourteen unique transposon insertions were mapped to pptAB, an ABC-type transporter recently described to export sex pheromones of Enterococcus faecalis. Consistent with an idea that PptAB exports signaling peptides, the pheromones known as SHPs (short hydrophobic peptides) were no longer detected in cell-free culture supernatants in a generated deletion mutant of pptAB. PptAB exporters are conserved among the Firmicutes, but their function and substrates remain unclear. Therefore, we tested a pptAB mutant generated in Streptococcus mutans and found that while secretion of heterologously expressed SHP peptides required PptAB, secretion of the S. mutans endogenous pheromone XIP (sigX inducing peptide) was only partially disrupted, indicating that a secondary secretion pathway for XIP exists.