The SAL1 gene of Arabidopsis, encoding an enzyme with 3'(2'),5'-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase activities, increases salt tolerance in yeast
The SAL1 gene of Arabidopsis, encoding an enzyme with 3'(2'),5'-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase activities, increases salt tolerance in yeast
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DOI：
10.1105/tpc.8.3.529
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发表时间：
1996-03-01
期刊：
影响因子：
11.6
通讯作者：
RodriguezNavarro, A
中科院分区：
文献类型：
--
作者：
Quintero, FJ;Garciadeblas, B;RodriguezNavarro, A
以盐胁迫下的拟南芥根系为材料，构建酵母表达载体cDNA文库，用于筛选耐Li+酵母转化子。从其中一个转化子中分离到的cDNA SAL1编码353个氨基酸残基的多肽。该蛋白分别与酵母和大肠杆菌的HAL2和CysQ磷酸酶同源。数据库中的部分cDNA序列表明，水稻产生一个与SAL1高度同源的磷酸酶，而拟南芥中也存在一个与SAL1高度同源的基因。在大肠杆菌中表达的SAL1蛋白具有3'(2',5')-二磷酸核苷酸酶和肌醇多磷酸1-磷酸酶活性。在酵母中，SAL1恢复了hal2/met22突变体在硫酸盐作为唯一硫源上生长的能力，增加了细胞内Li+的耐受性，并改变了Na+和Li+的外排。我们认为SAL1的产物参与硫同化途径和磷酸肌苷信号通路，后者的变化可能影响Na+和Li+通量。
A cDNA library in a yeast expression vector was prepared from roots of Arabidopsis exposed to salt and was used to select Li+-tolerant yeast transformants. The cDNA SAL1 isolated from one of these transformants encodes a polypeptide of 353 amino acid residues. This protein is homologous to the HAL2 and CysQ phosphatases of yeast and Escherichia coli, respectively. Partial cDNA sequences in the data bases indicate that rice produces a phosphatase highly homologous to SAL1 and that a second gene homologous to SAL1 exists in Arabidopsis. The SAL1 protein expressed in E. coli showed 3'(2',5'-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase activities. In yeast, SAL1 restored the ability of a hal2/met22 mutant to grow on sulfate as a sole sulfur source, increased the intracellular Li+ tolerance, and modified Na+ and Li+ effluxes. We propose that the product of SAL1 participates in the sulfur assimilation pathway as well as in the phosphoinositide signaling pathway and that changes in the latter may affect Na+ and Li+ fluxes.