嗜热菌,生活在80°C以上的环境中,通常与多种极端环境压力耦合,由于它们在生物技术中的应用潜力以及原始的现存生命形式,因此引起了极大的关注。对它们的生存和适应机制的研究扩展了我们对生命如何在极端条件下茁壮成长的理解。在这些研究中,在极端高温和其他环境压力之间观察到各种生物的“交叉胁迫”行为。尽管有广泛的观察,在超嗜热菌中,交叉应力行为的全球观点仍不清楚,在我们对极端适应的理解中留下了知识空白。在这项研究中,我们在极端温度下进行了全球定量蛋白质组学分析,pH值,静水压力(HP),和一个古细菌菌株的盐度,热球菌A501,在广泛的温度范围内(50-100°C)具有出色的生长能力,pH(4-9),和HP(0.1-70MPa),但NaCl的范围很窄(1.0-5.0%,w/v)。蛋白质组分析(79.8%的基因组覆盖率)表明,大约61.5%的显著差异表达的蛋白质(DEP)响应于多种应激。对大多数测试应力的响应密切相关,除了对高盐度和低温的反应。前三个丰富的通用响应过程包括大分子的生物合成和保护,氨基酸的生物合成和代谢,离子传输,和有约束力的活动。此外,这项研究还揭示了特定的双重应激反应过程,如冷和HP胁迫的膜脂以及高渗和热应力的信号转导,以及钠依赖性的能量过程可能是盐度生长范围的限制因素。本研究是第一个在蛋白质组水平上检查嗜压嗜热菌中全局交叉应激反应的研究。我们的发现提供了交叉应激适应策略(33.5%的编码基因)对多种胁迫的直接证据,并突出了对极端温度的特定和独特的响应过程(每个编码基因的0.22-0.63%)。pH值,盐度,和压力,与进化生物学以及下一代工业生物技术(NGIB)领域高度相关。
Hyperthermophiles, living in environments above 80°C and usually coupling with multi-extreme environmental stresses, have drawn great attention due to their application potential in biotechnology and being the primitive extant forms of life. Studies on their survival and adaptation mechanisms have extended our understanding on how lives thrive under extreme conditions. During these studies, the \"cross-stress\" behavior in various organisms has been observed between the extreme high temperature and other environmental stresses. Despite the broad observation, the global view of the cross-stress behavior remains unclear in hyperthermophiles, leaving a knowledge gap in our understanding of extreme adaptation. In this study, we performed a global quantitative proteomic analysis under extreme temperatures, pH, hydrostatic pressure (HP), and salinity on an archaeal strain, Thermococcus eurythermalis A501, which has outstanding growth capability on a wide range of temperatures (50-100°C), pH (4-9), and HPs (0.1-70 MPa), but a narrow range of NaCl (1.0-5.0 %, w/v). The proteomic analysis (79.8% genome coverage) demonstrated that approximately 61.5% of the significant differentially expressed proteins (DEPs) responded to multiple stresses. The responses to most of the tested stresses were closely correlated, except the responses to high salinity and low temperature. The top three enriched universal responding processes include the biosynthesis and protection of macromolecules, biosynthesis and metabolism of amino acids, ion transport, and binding activities. In addition, this study also revealed that the specific dual-stress responding processes, such as the membrane lipids for both cold and HP stresses and the signal transduction for both hyperosmotic and heat stresses, as well as the sodium-dependent energetic processes might be the limiting factor of the growth range in salinity. The present study is the first to examine the global cross-stress responses in a piezophilic hyperthermophile at the proteomic level. Our findings provide direct evidences of the cross-stress adaptation strategy (33.5% of coding-genes) to multiple stresses and highlight the specific and unique responding processes (0.22-0.63% of coding genes for each) to extreme temperature, pH, salinity, and pressure, which are highly relevant to the fields of evolutionary biology as well as next generation industrial biotechnology (NGIB).