The alternative sigma factor SigF is a key player in the control of secretion mechanisms in Synechocystis sp. PCC 6803
The alternative sigma factor SigF is a key player in the control of secretion mechanisms in Synechocystis sp. PCC 6803
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DOI：
10.1111/1462-2920.14465
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发表时间：
2019-01-01
影响因子：
5.1
通讯作者：
Tamagnini, Paula
中科院分区：
文献类型：
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作者：
Flores, Carlos;Santos, Marina;Tamagnini, Paula
蓝藻替代性σ因子是环境适应过程中的重要参与者，其可能涉及与维持细胞被膜和控制分泌途径相关的细菌反应。在这里，我们表明，第3组替代西格玛因子F（SigF）在集胞藻属PCC 6803生理学中起着多效性作用，对生长和分泌机制产生重大影响，如胞外多糖的产生，囊泡形成和蛋白质分泌。虽然Delta sigF生长显著受损，但与野生型相比，释放的多糖（RPS）的产生增加了三倍至四倍。δ sigF还表现出外膜囊泡（OMV）和皮利形成的损伤，以及几种其他细胞包膜的改变。类似地，Delta sigF的外切蛋白质组组成在所鉴定的蛋白质的量和类型方面均不同于野生型。定量蛋白质组学（iTRAQ）和SigF结合基序的计算机分析揭示了SigF控制下的可能靶点/途径。除了参与分泌机制的蛋白质水平的变化，我们的研究结果表明，光合作用，中央碳代谢和蛋白质折叠/降解机制的改变在德尔塔sigF。总之，这项工作为SigF在集胞藻生理学中的作用提供了新的证据，并将这种调节元件与经典和非经典的分泌途径联系起来。
Cyanobacterial alternative sigma factors are crucial players in environmental adaptation processes, which may involve bacterial responses related to maintenance of cell envelope and control of secretion pathways. Here, we show that the Group 3 alternative sigma factor F (SigF) plays a pleiotropic role in Synechocystis sp. PCC 6803 physiology, with a major impact on growth and secretion mechanisms, such as the production of extracellular polysaccharides, vesiculation and protein secretion. Although Delta sigF growth was significantly impaired, the production of released polysaccharides (RPS) increased threefold to fourfold compared with the wild-type. Delta sigF exhibits also impairment in formation of outer-membrane vesicles (OMVs) and pili, as well as several other cell envelope alterations. Similarly, the exoproteome composition of Delta sigF differs from the wild-type both in amount and type of proteins identified. Quantitative proteomics (iTRAQ) and an in silico analysis of SigF binding motifs revealed possible targets/pathways under SigF control. Besides changes in protein levels involved in secretion mechanisms, our results indicated that photosynthesis, central carbon metabolism and protein folding/degradation mechanisms are altered in Delta sigF. Overall, this work provided new evidences about the role of SigF on Synechocystis physiology and associates this regulatory element with classical and non-classical secretion pathways.