A new quorum-sensing system (TprA/PhrA) for Streptococcus pneumoniae D39 that regulates a lantibiotic biosynthesis gene cluster.
A new quorum-sensing system (TprA/PhrA) for Streptococcus pneumoniae D39 that regulates a lantibiotic biosynthesis gene cluster.
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DOI：
10.1111/mmi.13029
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发表时间：
2015-07
影响因子：
3.6
通讯作者：
Lazazzera BA
中科院分区：
文献类型：
--
作者：
Hoover SE;Perez AJ;Tsui HC;Sinha D;Smiley DL;DiMarchi RD;Winkler ME;Lazazzera BA
芽孢杆菌的Phr多肽介导群体感应，但它们在其他细菌中的鉴定和功能尚未确定。我们已经确定了一种Phr多肽群体感应系统(TprA/Phra)，它控制着革兰氏阳性人类病原体肺炎链球菌中抗生素基因簇的表达。抗生素是高度修饰的多肽，属于细菌素家族的抗菌肽。我们已经描述了肺炎链球菌Phr肽信号系统的基本机制，并发现当肺炎球菌细胞在高密度下存在半乳糖时，它诱导抗生素基因的表达，半乳糖是人鼻咽的一种主要糖，这是一个高度竞争的微生物环境。当肺炎链球菌在侵袭性疾病期间遇到的首选碳源和最普遍的糖-葡萄糖一起生长时，看不到Phr肽系统的活性。因此，l抗生素基因的表达受Phr多肽系统的细胞密度信号和来自碳源的营养信号的控制，这表明群体感应和l抗生素机制可能帮助肺炎球菌细胞在鼻咽定植期间竞争空间和资源。
The Phr peptides of Bacillus species mediate quorum sensing, but their identification and function in other species of bacteria has not been determined. We have identified a Phr peptide quorum sensing system (TprA/PhrA) that controls the expression of a lantibiotic gene cluster in the Gram-positive human pathogen, Streptococcus pneumoniae. Lantibiotics are highly modified peptides that are part of the bacteriocin family of antimicrobial peptides. We have characterized the basic mechanism for a Phr peptide signaling system in S. pneumoniae and found that it induces expression of the lantibiotic genes when pneumococcal cells are at high density in the presence of galactose, a main sugar of the human nasopharynx, a highly competitive microbial environment. Activity of the Phr peptide system is not seen when pneumococcal cells are grown with glucose, the preferred carbon source and the most prevalent sugar encountered by S. pneumoniae during invasive disease. Thus, the lantibiotic genes are expressed under the control of both cell density signals via the Phr peptide system and nutritional signals from the carbon source present, suggesting that quorum sensing and the lantibiotic machinery may help pneumococcal cells compete for space and resources during colonization of the nasopharynx.