Systematic genetic dissection of chitin degradation and uptake in Vibrio cholerae.
Systematic genetic dissection of chitin degradation and uptake in Vibrio cholerae.
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DOI：
10.1111/1462-2920.13866
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发表时间：
2017-10
影响因子：
5.1
通讯作者：
Dalia AB
中科院分区：
文献类型：
--
作者：
Hayes CA;Dalia TN;Dalia AB
霍乱弧菌是水环境中的一种天然居民，在水环境中，常见的营养物质是微小甲壳类动物的几丁质外骨骼。几丁质的利用需要几丁质酶，几丁质酶将这种不溶于水的聚合物降解成可溶的几丁质低聚糖。这些低聚糖也是弧菌物种自然转化的诱导线索。霍乱弧菌基因组中预测有7个内切几丁质酶样基因。在这里，我们系统地剖析了每个基因对甲壳素生长的贡献以及对自然转化的诱导。具体地说，我们创造了一个缺乏所有7种推定的几丁质酶的菌株，并从这个菌株产生了一组菌株，每个菌株都表达一种几丁质酶。我们还构建了在我们的几丁质酶缺陷菌株中异位表达所有7种几丁质酶的表达载体。通过这一分析，我们发现低水平的几丁质酶活性足以进行自然转化，而以不溶性几丁质为唯一碳源生长需要更强劲和协调的几丁质酶活性。我们还评估了甲壳素降解产物GlcNAc、(GlcNAc)2和(GlcN)2的三种摄取系统在甲壳素利用和竞争诱导中的作用。总而言之，这项研究提供了这种病原体如何利用甲壳素在其环境水库中茁壮成长和进化的机制细节。
Vibrio cholerae is a natural resident of the aquatic environment, where a common nutrient is the chitinous exoskeletons of microscopic crustaceans. Chitin utilization requires chitinases, which degrade this insoluble polymer into soluble chitin oligosaccharides. These oligosaccharides also serve as an inducing cue for natural transformation in Vibrio species. There are 7 predicted endochitinase-like genes in the V. cholerae genome. Here, we systematically dissect the contribution of each gene to growth on chitin as well as induction of natural transformation. Specifically, we created a strain that lacks all 7 putative chitinases and from this strain, generated a panel of strains where each expresses a single chitinase. We also generated expression plasmids to ectopically express all 7 chitinases in our chitinase deficient strain. Through this analysis, we found that low levels of chitinase activity are sufficient for natural transformation, while growth on insoluble chitin as a sole carbon source requires more robust and concerted chitinase activity. We also assessed the role that the three uptake systems for the chitin degradation products GlcNAc, (GlcNAc)2, and (GlcN)2, play in chitin utilization and competence induction. Cumulatively, this study provides mechanistic details for how this pathogen utilizes chitin to thrive and evolve in its environmental reservoir.
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影响因子：
3.2
作者：
Dalia, Ankur B.;Lazinski, David W.;Camilli, Andrew
通讯作者：
Camilli, Andrew
影响因子：
4.8
作者：
Keyhani, NO;Roseman, S
通讯作者：
Roseman, S
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2.8
作者：
Mondal, Moumita;Chatterjee, Nabendu Sekhar
通讯作者：
Chatterjee, Nabendu Sekhar
影响因子：
4.8
作者：
Keyhani, NO;Li, XB;Roseman, S
通讯作者：
Roseman, S
影响因子：
64.8
作者：
Wang HH;Isaacs FJ;Carr PA;Sun ZZ;Xu G;Forest CR;Church GM
通讯作者：
Church GM