Involvement of Vacuolar Sequestration and Active Transport in Tolerance of Saccharomyces cerevisiae to Hop Iso-α-Acids
Involvement of Vacuolar Sequestration and Active Transport in Tolerance of Saccharomyces cerevisiae to Hop Iso-α-Acids
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DOI：
10.1128/aem.01457-09
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发表时间：
2010-01-01
影响因子：
4.4
通讯作者：
Daran, Jean-Marc
中科院分区：
文献类型：
--
作者：
Hazelwood, Lucie A.;Walsh, Michael C.;Daran, Jean-Marc
啤酒花植物葎草（Humulus lupulus L.）具有极高的次生代谢产物，即啤酒花α -酸，它具有一系列有益的特性，包括防腐作用。迄今为止，对啤酒花异α -酸作用方式的研究仅限于乳酸菌。本文研究了酿酒酵母菌对啤酒花异- α -酸抗性的分子机制。啤酒花异α -酸浓度比啤酒花耐受原核生物的浓度高一个数量级。利用基于化学抑制因子的转录组分析和酿酒酵母单倍体基因缺失收集的表型筛选作为补充方法，筛选与啤酒花异α -酸解毒和耐受相关的基因。对缺失突变体的筛选和进一步分析证实，酵母对啤酒花异α -酸的耐受涉及三个主要过程：通过液泡型atp酶将质子主动泵入液泡，使异α -酸能够在液泡中隔离并改变细胞壁结构；在较小程度上，通过质膜主动输出异α -酸。此外，异α -酸被证明通过作为强锌和铁螯合剂影响细胞金属稳态。
The hop plant, Humulus lupulus L., has an exceptionally high content of secondary metabolites, the hop alpha-acids, which possess a range of beneficial properties, including antiseptic action. Studies performed on the mode of action of hop iso-alpha-acids have hitherto been restricted to lactic acid bacteria. The present study investigated molecular mechanisms of hop iso-alpha-acid resistance in the model eukaryote Saccharomyces cerevisiae. Growth inhibition occurred at concentrations of hop iso-alpha-acids that were an order of magnitude higher than those found with hop-tolerant prokaryotes. Chemostat-based transcriptome analysis and phenotype screening of the S. cerevisiae haploid gene deletion collection were used as complementary methods to screen for genes involved in hop iso-alpha-acid detoxification and tolerance. This screening and further analysis of deletion mutants confirmed that yeast tolerance to hop iso-alpha-acids involves three major processes, active proton pumping into the vacuole by the vacuolar-type ATPase to enable vacuolar sequestration of iso-alpha-acids and alteration of cell wall structure and, to a lesser extent, active export of iso-alpha-acids across the plasma membrane. Furthermore, iso-alpha-acids were shown to affect cellular metal homeostasis by acting as strong zinc and iron chelators.