Increasing intracellular trehalose is sufficient to confer desiccation tolerance to Saccharomyces cerevisiae
Increasing intracellular trehalose is sufficient to confer desiccation tolerance to Saccharomyces cerevisiae
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DOI：
10.1073/pnas.1506415112
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发表时间：
2015-05-12
影响因子：
11.1
通讯作者：
Koshland, Douglas
中科院分区：
文献类型：
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作者：
Tapia, Hugo;Young, Lindsey;Koshland, Douglas
能够在干燥中生存的多种生物体，称为脱水生物，包括来自细菌、酵母、植物和无脊椎动物的物种。然而，大多数生物体对干燥敏感，可能是由于各种不同的应激，如蛋白质错误折叠和聚集、高渗应激、膜破裂以及细胞体积和形状的变化导致细胞质过度拥挤和代谢停滞。导致干燥敏感生物体死亡的确切应激以及如何减轻耐干燥生物体中的致死应激仍然知之甚少。脱水生物中海藻糖的存在与干燥耐受性密切相关。在酿酒酵母中，海藻糖对于长期干燥后的生存至关重要。在这里，我们确定，分裂酵母中细胞内海藻糖的升高是由于从培养基中输入海藻糖，将酵母从极度干燥敏感性转变为高水平的干燥耐受性。这种海藻糖诱导的耐受性与海藻糖作为能源的利用、其他应激效应物的从头合成或海藻糖生物合成中间体的代谢作用无关，表明海藻糖的化学性质直接负责干燥耐受性。最后，我们证明细胞内麦芽糖升高也可以使分裂酵母耐受短期干燥，这表明其他二糖具有应激效应活性。然而，海藻糖在赋予长期干燥耐受性方面比麦芽糖更有效。海藻糖作为酵母中干燥引起的损伤的拮抗剂的有效性和充分性强调了其赋予其他敏感生物体干燥耐受性的潜力。
Diverse organisms capable of surviving desiccation, termed anhydrobiotes, include species from bacteria, yeast, plants, and invertebrates. However, most organisms are sensitive to desiccation, likely due to an assortment of different stresses such as protein misfolding and aggregation, hyperosmotic stress, membrane fracturing, and changes in cell volume and shape leading to an overcrowded cytoplasm and metabolic arrest. The exact stress(es) that cause lethality in desiccation-sensitive organisms and how the lethal stresses are mitigated in desiccation-tolerant organisms remain poorly understood. The presence of trehalose in anhydrobiotes has been strongly correlated with desiccation tolerance. In the yeast Saccharomyces cerevisiae, trehalose is essential for survival after long-term desiccation. Here, we establish that the elevation of intracellular trehalose in dividing yeast by its import from the media converts yeast from extreme desiccation sensitivity to a high level of desiccation tolerance. This trehalose-induced tolerance is independent of utilization of trehalose as an energy source, de novo synthesis of other stress effectors, or the metabolic effects of trehalose biosynthetic intermediates, indicating that a chemical property of trehalose is directly responsible for desiccation tolerance. Finally, we demonstrate that elevated intracellular maltose can also make dividing yeast tolerant to short-term desiccation, indicating that other disaccharides have stress effector activity. However, trehalose is much more effective than maltose at conferring tolerance to long-term desiccation. The effectiveness and sufficiency of trehalose as an antagonizer of desiccation-induced damage in yeast emphasizes its potential to confer desiccation tolerance to otherwise sensitive organisms.