Singer M A, Lindquist S
Department of Pathology, Howard Hughes Medical Institute, University of Chicago, Illinois 60637, USA.
Mol Cell. 1998 Apr;1(5):639-48. doi: 10.1016/s1097-2765(00)80064-7.
The disaccharide trehalose is produced in large quantities by diverse organisms during a variety of stresses. Trehalose prevents proteins from denaturing at high temperatures in vitro, but its function in stress tolerance in vivo is controversial. We report that trehalose stabilizes proteins in yeast cells during heat shock. Surprisingly, trehalose also suppresses the aggregation of denatured proteins, maintaining them in a partially-folded state from which they can be activated by molecular chaperones. The continued presence of trehalose, however, interferes with refolding, suggesting why it is rapidly hydrolyzed following heat shock. These findings reconcile conflicting reports on the role of trehalose in stress tolerance, provide a novel tool for accessing protein folding intermediates, and define new parameters for modulating stress tolerance and protein aggregation.
二糖海藻糖在多种应激情况下由不同生物体大量产生。海藻糖在体外可防止蛋白质在高温下变性，但其在体内应激耐受中的功能存在争议。我们报告称，海藻糖在热休克期间能稳定酵母细胞中的蛋白质。令人惊讶的是，海藻糖还能抑制变性蛋白质的聚集，使其维持在部分折叠状态，分子伴侣可由此激活这些蛋白质。然而，海藻糖的持续存在会干扰重折叠，这解释了热休克后海藻糖迅速水解的原因。这些发现调和了关于海藻糖在应激耐受中作用的相互矛盾的报道，提供了一种获取蛋白质折叠中间体的新工具，并定义了调节应激耐受和蛋白质聚集的新参数。
