A Selaginella lepidophylla trehalose-6-phosphate synthase complements growth and stress-tolerance defects in a yeast tps1 mutant.
A Selaginella lepidophylla trehalose-6-phosphate synthase complements growth and stress-tolerance defects in a yeast tps1 mutant.
复制标题
DOI：
10.1104/pp.119.4.1473
复制
发表时间：
1999-04
期刊：
影响因子：
7.4
通讯作者：
Rodolfo Zentella;J. MASCORRO-GALLARDO;P. Dijck;J. Folch-Mallol;B. Bonini;C. V. Vaeck;Roberto A. Gaxiola-Roberto
中科院分区：
文献类型：
--
作者：
Rodolfo Zentella;J. MASCORRO-GALLARDO;P. Dijck;J. Folch-Mallol;B. Bonini;C. V. Vaeck;Roberto A. Gaxiola-Roberto
二糖海藻糖在无水生物体内的积累使它们能够在严重的环境压力下生存下来。从富含海藻糖的复活植物卷柏中分离到一个编码109-kD蛋白的植物基因SLTPS1。蛋白质序列比较表明，SLTPS1与原核生物和真核生物的海藻糖-6-磷酸合成酶基因具有很高的相似性。SLTPS1基因在鳞片藻中呈结构性表达。DNA凝胶印迹分析表明，SLTPS1为单拷贝基因。将ScTPS1基因中断的突变株转化酿酒酵母TPS1，可恢复发酵糖的生长和海藻糖的高水平合成。此外，将SlTPS1基因导入到tps1Delta突变体中可以弥补这两个缺陷：对39℃亚致死热处理的敏感性和在50℃诱导的耐热性。在氯化钠和山梨醇中生长的酵母tps1Delta突变体的渗透敏感表型也被SLTPS1基因恢复。因此，SLTPS1蛋白是一种能够维持海藻糖生物合成的功能植物同源物，可能在鳞茎海藻的逆境耐受性中发挥重要作用。
The accumulation of the disaccharide trehalose in anhydrobiotic organisms allows them to survive severe environmental stress. A plant cDNA, SlTPS1, encoding a 109-kD protein, was isolated from the resurrection plant Selaginella lepidophylla, which accumulates high levels of trehalose. Protein-sequence comparison showed that SlTPS1 shares high similarity to trehalose-6-phosphate synthase genes from prokaryotes and eukaryotes. SlTPS1 mRNA was constitutively expressed in S. lepidophylla. DNA gel-blot analysis indicated that SlTPS1 is present as a single-copy gene. Transformation of a Saccharomyces cerevisiae tps1Delta mutant disrupted in the ScTPS1 gene with S. lepidophylla SlTPS1 restored growth on fermentable sugars and the synthesis of trehalose at high levels. Moreover, the SlTPS1 gene introduced into the tps1Delta mutant was able to complement both deficiencies: sensitivity to sublethal heat treatment at 39 degrees C and induced thermotolerance at 50 degrees C. The osmosensitive phenotype of the yeast tps1Delta mutant grown in NaCl and sorbitol was also restored by the SlTPS1 gene. Thus, SlTPS1 protein is a functional plant homolog capable of sustaining trehalose biosynthesis and could play a major role in stress tolerance in S. lepidophylla.