期刊
GENE
卷 369, 期 -, 页码 27-34出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.gene.2005.10.007
关键词
yeast; halotolerance; Na+/H+ antiporter; cation efflux
Debaryommyces hansenii is a yeast species often round in salty environments. Its genome sequence is known completely, but the mechanisms behind its halotolerance are poorly understood. In the D. hansenii genome, there is a gene strongly homologous to the Saccharomyces cerevisiae NHA1 gene (encoding a plasma membrane Na+/H+ antiporter). We isolated this DhNHA1 gene from two D. hansenii strains (CBS 767 and CBS 1793) differing in their osmotolerance. Both DhANHA1 alleles were heterologously expressed in a S. cerevisiae strain lacking its own systems for the efflux of alkali metal cations (BW31a, ena1-4 Delta nha1 Delta). D. hansenii Na+/H+ antiporters were localized in the plasma membrane of BW3 la cells, their presence increased BW31a tolerance to sodium, potassium, lithium and also rubidium. Measurements of Na+ and K+ efflux from S. cerevisiae cells expressing DhNHA1 alleles show that the D. hansenii antiporters efficiently transported both cations out of cells. The sodium and potassium transport activity of Nha1 antiporters from both D. hansenii strains was almost identical, indicating that plasma membrane antiporter activity is not one of the factors determining the different levels of halotolerance in the two strains. (C) 2005 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据