The effects of mycobacterial RmlA perturbation on cellular dNTP pool, cell morphology, and replication stress in Mycobacterium smegmatis.
The effects of mycobacterial RmlA perturbation on cellular dNTP pool, cell morphology, and replication stress in Mycobacterium smegmatis.
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分枝杆菌RMLA扰动对分枝杆菌中细胞DNTP库，细胞形态和复制应激的影响。
DOI：
10.1371/journal.pone.0263975
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发表时间：
2022
期刊：
影响因子：
3.7
通讯作者：
Tóth J
中科院分区：
文献类型：
--
作者：
Hirmondó R;Horváth Á;Molnár D;Török G;Nguyen L;Tóth J
DNA 复制和细胞分裂的协同作用已在真核生物中得到广泛研究。细胞周期中已确定了界限分明的检查点，这为后代提供了正确的 DNA 化学计量和适当的生长。与真核生物相比，细菌生长速度更快，协调性也较差，因此细胞伸长和 DNA 合成之间的联系尚不清楚。 dTTP 是 DNA 的经典核苷酸构建块之一，也用于分枝杆菌的细胞壁生物合成。我们假设 DNA 和细胞壁生物合成之间通过 dTTP 的互连可能需要通过调节 dTTP 的可用性来同步这些过程。我们研究了耻垢分枝杆菌的生长、形态、细胞 dNTP 池以及在 RmlA 过度表达扰乱鼠李糖生物合成时可能出现的应激迹象。 RmlA 是一种细胞壁合成酶，它使用 dTTP 作为前体，通过分枝杆菌细胞壁中的磷酸二酯键将肽聚糖与阿拉伯半乳聚糖层交联。我们发现 RmlA 过度表达会导致细胞形态的变化，导致细胞伸长和圆柱形细胞形状的破坏。我们还发现，在 RmlA 过表达细胞中，细胞 dTTP 池减少了一半，并且这种减少的 dTTP 可用性不会限制细胞生长。我们观察到 RmlA 过表达后复制和细胞壁生物合成应激因子的基因表达增加了 2-6 倍。使用超分辨率显微镜，我们发现 RmlA 负责交联细胞壁的新生层，除了细胞极之外，它还以螺旋模式定位在整个细胞长度上。
The concerted action of DNA replication and cell division has been extensively investigated in eukaryotes. Well demarcated checkpoints have been identified in the cell cycle, which provides the correct DNA stoichiometry and appropriate growth in the progeny. In bacteria, which grow faster and less concerted than eukaryotes, the linkages between cell elongation and DNA synthesis are unclear. dTTP, one of the canonical nucleotide-building blocks of DNA, is also used for cell wall biosynthesis in mycobacteria. We hypothesize that the interconnection between DNA and cell wall biosynthesis through dTTP may require synchronization of these processes by regulating dTTP availability. We investigated growth, morphology, cellular dNTP pool, and possible signs of stress in Mycobacterium smegmatis upon perturbation of rhamnose biosynthesis by the overexpression of RmlA. RmlA is a cell wall synthetic enzyme that uses dTTP as the precursor for cross-linking the peptidoglycan with the arabinogalactan layers by a phosphodiester bond in the mycobacterial cell wall. We found that RmlA overexpression results in changes in cell morphology, causing cell elongation and disruption of the cylindrical cell shape. We also found that the cellular dTTP pool is reduced by half in RmlA overexpressing cells and that this reduced dTTP availability does not restrict cell growth. We observed 2-6-fold increases in the gene expression of replication and cell wall biosynthesis stress factors upon RmlA overexpression. Using super-resolution microscopy, we found that RmlA, acting to crosslink the nascent layers of the cell wall, localizes throughout the whole cell length in a helical pattern in addition to the cellular pole.
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影响因子：
3.6
作者：
Hartmann, Raimo;van Teeseling, Muriel C. F.;Drescher, Knut
通讯作者：
Drescher, Knut
影响因子：
4.9
作者：
Ma, YF;Stern, RJ;McNeil, MR
通讯作者：
McNeil, MR
影响因子：
3.6
作者：
Cowley, S;Ko, M;Av-Gay, Y
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Av-Gay, Y
影响因子：
4.6
作者：
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通讯作者：
Khan, Inshad Ali
影响因子：
2.1
作者：
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通讯作者：
Parish, T