背景:空肠弯曲杆菌的主要天然储库是禽类肠道。在那里,空肠杆菌在42°C-禽类体温下最佳繁殖。通过口服摄入感染人类后,细菌在人体肠道中遇到37°C的较低温度。通过无标记质谱(DIA-MS)进行蛋白质组分析,以检查使空肠弯曲杆菌81-176在37°C与42°C相比茁壮成长的过程。总的来说,四个状态相互比较:在37°C下孵育12小时,在37°C下24小时,在42°C下持续12小时,在42°C下持续24小时。
结果:结果表明,当比较37°C和42°C以及12小时和24小时的孵育时,蛋白质组的变化不仅取决于孵育温度的不同,而且取决于孵育时间的长短。总之,957种蛋白质的表达是可量化的.37.1-47.3%的蛋白质分析显示出显着的差异调节,在任一方向上变化至少1.5倍(即log2FC≥0.585或log2FC≤-0.585),且FDR调整后的p值小于0.05。显著差异表达的蛋白质可以排列成4个不同的簇和16个功能类别。
结论:与37°C相比,42°C时的空肠弯曲菌蛋白质组更好地适应高复制率,这特别是由属于功能类别“复制”的蛋白质的上调(例如Obg,ParABS,和NapL),“DNA合成和修复因子”(例如DNA聚合酶III,DnaB,和DnaE),“脂质和碳水化合物生物合成”(例如荚膜生物合成糖激酶,PrsA,AccA,和AccP)和“维生素合成,新陈代谢,辅因子生物合成\“(例如MobB,BioA,和ThiE)。具有伴侣功能的蛋白质的相对上调(GroL,DnaK,ClpB,HslU,GroS,DnaJ,DnaJ-1和NapD)在37°C孵育12小时后与42°C相比,表明暂时的低温蛋白质组学反应。此外,与42°C相比,37°C时DNA摄取因子(ComEA和RecA)的上调表明,在人体温度下获取外来DNA的能力更高。
BACKGROUND: The main natural reservoir for Campylobacter jejuni is the avian intestinal tract. There, C. jejuni multiplies optimally at 42 °C - the avian body temperature. After infecting humans through oral intake, the bacterium encounters the lower temperature of 37 °C in the human intestinal tract. Proteome profiling by label-free mass spectrometry (DIA-MS) was performed to examine the processes which enable C. jejuni 81-176 to thrive at 37 °C in comparison to 42 °C. In total, four states were compared with each other: incubation for 12 h at 37 °C, for 24 h at 37 °C, for 12 h at 42 °C and 24 h at 42 °C.
RESULTS: It was shown that the proteomic changes not only according to the different incubation temperature but also to the length of the incubation period were evident when comparing 37 °C and 42 °C as well as 12 h and 24 h of incubation. Altogether, the expression of 957 proteins was quantifiable. 37.1 - 47.3% of the proteins analyzed showed significant differential regulation, with at least a 1.5-fold change in either direction (i.e. log2 FC ≥ 0.585 or log2 FC ≤ -0.585) and an FDR-adjusted p-value of less than 0.05. The significantly differentially expressed proteins could be arranged in 4 different clusters and 16 functional categories.
CONCLUSIONS: The C. jejuni proteome at 42 °C is better adapted to high replication rates than that at 37 °C, which was in particular indicated by the up-regulation of proteins belonging to the functional categories \"replication\" (e.g. Obg, ParABS, and NapL), \"DNA synthesis and repair factors\" (e.g. DNA-polymerase III, DnaB, and DnaE), \"lipid and carbohydrate biosynthesis\" (e.g. capsular biosynthesis sugar kinase, PrsA, AccA, and AccP) and \"vitamin synthesis, metabolism, cofactor biosynthesis\" (e.g. MobB, BioA, and ThiE). The relative up-regulation of proteins with chaperone function (GroL, DnaK, ClpB, HslU, GroS, DnaJ, DnaJ-1, and NapD) at 37 °C in comparison to 42 °C after 12 h incubation indicates a temporary lower-temperature proteomic response. Additionally the up-regulation of factors for DNA uptake (ComEA and RecA) at 37 °C compared to 42 °C indicate a higher competence for the acquisition of extraneous DNA at human body temperature.