Deletion of genes encoding fatty acid desaturases leads to alterations in stress sensitivity in Pichia pastoris.
Deletion of genes encoding fatty acid desaturases leads to alterations in stress sensitivity in Pichia pastoris.
复制标题
DOI：
10.1093/femsyr/fov020
复制
发表时间：
2015-06
影响因子：
3.2
通讯作者：
Meng Zhang;Zhe Liu;Qilin Yu;Jiwei Mao;Biao Zhang;L. Xing;Mingchun Li
中科院分区：
文献类型：
--
作者：
Meng Zhang;Zhe Liu;Qilin Yu;Jiwei Mao;Biao Zhang;L. Xing;Mingchun Li
不饱和脂肪酸（UFA）是关键化合物，在维持细胞膜生理功能和适应恶劣条件方面发挥着重要作用。脂肪酸去饱和酶的缺陷会改变细胞的UFA构成。毕赤酵母GS115具有四种脂肪酸去饱和酶基因，即FAD9A、FAD9B、FAD12和FAD15。他们的产品分别催化合成三种UFA：油酸（由Fad9A和Fad9B催化）、亚油酸（由Fad12催化）和α-亚麻酸（由Fad15催化）。在这项研究中，我们发现 FAD12 的缺失会导致对氧化应激的抵抗力增强。经过 H2O2 处理后，fad12Δ 突变体的细胞脂质过氧化水平下降。细胞脂肪酸组成随着 FAD9A 表达的增加而改变。另一方面，FAD9A 的缺失导致对质膜（PM）损伤剂 SDS 的耐受性增加，并且在这种胁迫下，在 fad9AΔ 突变体中没有检测到 PM 变形。我们的结果表明，UFA 与细胞对不利环境变化的适应有关。
Unsaturated fatty acids (UFAs) are key compounds which have important roles in maintaining cell membrane physiological functions and the adaption to tough conditions. Defects of fatty acid desaturases will change cellular UFA constitution. Pichia pastoris GS115 has four fatty acid desaturase genes, namely FAD9A, FAD9B, FAD12 and FAD15. Their products catalyze the synthesis of three kinds of UFAs, oleic acid (catalyzed by Fad9A and Fad9B), linoleic acid (catalyzed by Fad12) and α-linolenic acid (catalyzed by Fad15), respectively. In this study, we found that deletion of FAD12 led to increased resistance to oxidative stress. Cellular lipid peroxidation levels declined in the fad12Δ mutant upon H2O2 treatment. Cellular fatty acids compositions were changed with the increased expression of FAD9A. On the other hand, deletion of FAD9A resulted in increased tolerance to the plasma membrane (PM) damage agent SDS, and PM deformation was not detected in the fad9AΔ mutant under this stress. Our results showed that UFAs are related to cell adaption to adverse environmental changes.