Overproduction of individual gas vesicle proteins perturbs flotation, antibiotic production and cell division in the enterobacterium Serratia sp. ATCC 39006.
Overproduction of individual gas vesicle proteins perturbs flotation, antibiotic production and cell division in the enterobacterium Serratia sp. ATCC 39006.
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DOI：
10.1099/mic.0.000347
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发表时间：
2016-09
期刊：
影响因子：
1.5
通讯作者：
Rita E. Monson;Y. Tashiro;G. Salmond
中科院分区：
文献类型：
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作者：
Rita E. Monson;Y. Tashiro;G. Salmond
气泡是细胞内的蛋白质细胞器，有助于细菌在静态水柱中定植。在肠杆菌沙雷氏菌ATCC 39006中，气泡形成需要蛋白GvpA1、GvpF1、GvpG、GvpA2、GvpK、GvpA3、GvpF2和GvpF3以及三种气泡调节蛋白GvrA、GvrB和GvrC。gvpC的缺失改变了气体囊泡的稳健性，并且gvpN或gvpV的缺失导致小的双锥囊泡。在这项工作中，我们评估了当这14种必需蛋白中的每一种过表达时对气泡形成的影响。GvpF1、GvpF2、GvrA、GvrB或GvrC的过量产生均导致气泡合成显著减少。当GvpV和GvpA3过量时，也观察到气泡形成的扰动。除了对气体囊泡形成的影响之外，GvrA或GvrB的过度产生导致三吡咯色素灵菌红素的生物合成增加，灵菌红素是一种由于其抗疟疾和抗癌特性而引起越来越多医学兴趣的次级代谢物。最后，当GvpG过表达时，仍然产生气泡，但细胞表现出生长缺陷。进一步的分析表明，诱导GvpG逮捕细胞生长，并导致活细胞计数下降，这表明这种蛋白质连接气囊生物发生和二分裂可能的生理作用。这些综合结果表明，单个气泡蛋白的化学计量是至关重要的细胞器形态发生和浮选控制，并提供了证据的第一个气泡组装和细胞分裂之间的联系，据我们所知。
Gas vesicles are intracellular proteinaceous organelles that facilitate bacterial colonization of static water columns. In the enterobacterium Serratia sp. ATCC 39006, gas vesicle formation requires the proteins GvpA1, GvpF1, GvpG, GvpA2, GvpK, GvpA3, GvpF2 and GvpF3 and the three gas vesicle regulatory proteins GvrA, GvrB and GvrC. Deletion of gvpC alters gas vesicle robustness and deletion of gvpN or gvpV results in small bicone vesicles. In this work, we assessed the impacts on gas vesicle formation when each of these 14 essential proteins was overexpressed. Overproduction of GvpF1, GvpF2, GvrA, GvrB or GvrC all resulted in significantly reduced gas vesicle synthesis. Perturbations in gas vesicle formation were also observed when GvpV and GvpA3 were in excess. In addition to impacts on gas vesicle formation, overproduction of GvrA or GvrB led to elevated biosynthesis of the tripyrrole pigment, prodigiosin, a secondary metabolite of increasing medical interest due to its antimalarial and anticancer properties. Finally, when GvpG was overexpressed, gas vesicles were still produced, but the cells exhibited a growth defect. Further analysis showed that induction of GvpG arrested cell growth and caused a drop in viable count, suggesting a possible physiological role for this protein linking gas vesicle biogenesis and binary fission. These combined results demonstrate that the stoichiometry of individual gas vesicle proteins is crucially important for controlled organelle morphogenesis and flotation and provides evidence for the first link between gas vesicle assembly and cell division, to our knowledge.