Competence-independent activity of pneumococcal EndA [corrected] mediates degradation of extracellular dna and nets and is important for virulence.
Competence-independent activity of pneumococcal EndA [corrected] mediates degradation of extracellular dna and nets and is important for virulence.
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DOI：
10.1371/journal.pone.0070363
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Lau GW
中科院分区：
文献类型：
--
作者：
Zhu L;Kuang Z;Wilson BA;Lau GW
肺部病原体肺炎链球菌（肺炎球菌）的膜表面定位核酸内切酶 EndA 是遗传转化和毒力所必需的。肺炎球菌在生长过程中表达 EndA。然而，据报道，当肺炎球菌细胞不具备遗传转化能力时，EndA 无法接触外部 DNA，因此无法降解细胞外 DNA。在这里，通过使用生化和遗传学方法，我们证明了 EndA 介导的溶核活性的存在，与肺炎球菌细胞的能力状态无关。在能力发育和遗传转化方面存在遗传缺陷的肺炎球菌突变体具有与其亲本野生型相当的细胞外核酸酶活性，包括降解中性粒细胞胞外陷阱（NET）的能力。自溶缺陷的 ΔlytA 突变体及其同基因胆碱处理的亲本野生型菌株 D39 很容易降解细胞外 DNA，表明 DNA 降解不需要部分细胞自溶。我们发现，EndA 分子在肺炎球菌细胞生长过程中分泌到培养基中，并对能力独立的溶核活性做出了重大贡献。 EndA 的能力独立活性负责 DNA 和 NET 的快速降解，并且是肺炎链球菌在肺部感染期间充分发挥毒力所必需的。
Membrane surface localized endonuclease EndA of the pulmonary pathogen Streptococcus pneumoniae (pneumococcus) is required for both genetic transformation and virulence. Pneumococcus expresses EndA during growth. However, it has been reported that EndA has no access to external DNA when pneumococcal cells are not competent for genetic transformation, and thus, unable to degrade extracellular DNA. Here, by using both biochemical and genetic methods, we demonstrate the existence of EndA-mediated nucleolytic activity independent of the competence state of pneumococcal cells. Pneumococcal mutants that are genetically deficient in competence development and genetic transformation have extracellular nuclease activity comparable to their parental wild type, including their ability to degrade neutrophil extracellular traps (NETs). The autolysis deficient ΔlytA mutant and its isogenic choline-treated parental wild-type strain D39 degrade extracellular DNA readily, suggesting that partial cell autolysis is not required for DNA degradation. We show that EndA molecules are secreted into the culture medium during the growth of pneumococcal cells, and contribute substantially to competence-independent nucleolytic activity. The competence-independent activity of EndA is responsible for the rapid degradation of DNA and NETs, and is required for the full virulence of Streptococcus pneumoniae during lung infection.
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影响因子：
3.2
作者：
Lee, MS;Morrison, DA
通讯作者：
Morrison, DA
影响因子：
3.2
作者：
Moscoso, Miriam;Garcia, Ernesto;Lopez, Rubens
通讯作者：
Lopez, Rubens
影响因子：
64.8
作者：
KOHOUTOVA, D
通讯作者：
KOHOUTOVA, D
研究肺炎球菌类型的诱导物质转化的化学性质：通过从III型肺炎球菌分离出的脱氧核糖核酸分数诱导转化。
DOI：
10.1084/jem.79.2.137
发表时间：
1944-02-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Avery OT;Macleod CM;McCarty M
通讯作者：
McCarty M
影响因子：
3.6
作者：
Pestova, EV;Havarstein, LS;Morrison, DA
通讯作者：
Morrison, DA