Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
Laboratory of Mass Spectrometry, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-807 Gdansk, Poland.
Int J Mol Sci. 2022 Jan 9;23(2):697. doi: 10.3390/ijms23020697.
In bacteria, the DsbA oxidoreductase is a crucial factor responsible for the introduction of disulfide bonds to extracytoplasmic proteins, which include important virulence factors. A lack of proper disulfide bonds frequently leads to instability and/or loss of protein function; therefore, improper disulfide bonding may lead to avirulent phenotypes. The importance of the DsbA function in phytopathogens has not been extensively studied yet. is a bacterium from the Soft Rot family which is responsible for very high economic losses mainly in potato. In this work, we constructed a mutant and demonstrated that a lack of DsbA caused a loss of virulence. The mutant bacteria showed lower activities of secreted virulence determinants and were unable to develop disease symptoms in a potato plant. The SWATH-MS-based proteomic analysis revealed that the mutation led to multifaceted effects in the cells, including not only lower levels of secreted virulence factors, but also the induction of stress responses. Finally, the outer membrane barrier seemed to be disturbed by the mutation. Our results clearly demonstrate that the function played by the DsbA oxidoreductase is crucial for virulence, and a lack of DsbA significantly disturbs cellular physiology.
在细菌中，DsbA 氧化还原酶是负责将二硫键引入细胞外蛋白质的关键因素，这些蛋白质包括重要的毒力因子。缺乏适当的二硫键通常会导致蛋白质不稳定和/或丧失功能；因此，不正确的二硫键形成可能导致无毒性表型。DsbA 功能在植物病原体中的重要性尚未得到广泛研究。 是一种软腐菌科的细菌，主要导致马铃薯遭受极高的经济损失。在这项工作中，我们构建了一个 突变体，并证明 DsbA 的缺乏导致了毒力的丧失。突变细菌表现出较低的分泌毒力决定因子活性，并且无法在马铃薯植株上引起疾病症状。基于 SWATH-MS 的蛋白质组学分析表明， 突变导致 细胞中出现多方面的影响，不仅降低了分泌的毒力因子水平，还诱导了应激反应。最后，似乎突变扰乱了外膜屏障。我们的结果清楚地表明，DsbA 氧化还原酶的功能对于 毒力至关重要，而 DsbA 的缺乏会严重扰乱细胞生理。
