Deletion of Atg22 gene contributes to reduce programmed cell death induced by acetic acid stress in Saccharomyces cerevisiae
Deletion of Atg22 gene contributes to reduce programmed cell death induced by acetic acid stress in Saccharomyces cerevisiae
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Atg22 基因的缺失有助于减少酿酒酵母乙酸应激诱导的程序性细胞死亡
DOI：
10.1186/s13068-019-1638-x
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发表时间：
2019-12
影响因子：
6.3
通讯作者：
Chen Qihe
中科院分区：
文献类型：
--
作者：
Hu Jingjin;Dong Yachen;Wang Wei;Zhang Wei;Lou Hanghang;Chen Qihe
背景
纤维素水解过程中产生的主要副产物乙酸诱导的细胞程序性死亡（PCD）给酿酒酵母发酵木质纤维素生物燃料蒙上了一层阴影，成为亟待解决的问题。Atg22p是一个被忽视的位于液泡中的膜蛋白，属于自噬相关基因家族，最近的研究表明它是自噬降解和氨基酸从液泡向细胞质外排的必需蛋白。它可以减轻醋酸引起的细胞内营养饥饿，提高细胞耐受性。因此，我们研究atg22在Ac诱导的细胞死亡过程中的作用，试图为更好地理解耐受性背后的机制和更强大的工业菌株构建发现新的视角。
结果
在这项研究中，我们比较了细胞的生长，生理变化的情况下，存在和存在Atg22p在AC暴露条件下。观察到Atg22p的破坏和过表达分别延迟和增强乙酸诱导的PCD。S.酿酒酵母通过改变细胞膜磷脂、甾醇和脂肪酸来维持细胞壁的完整性，并在Ac胁迫下保护细胞膜的完整性、流动性和渗透性。更有趣的是，atg22缺失增加了细胞内氨基酸，以帮助酵母细胞解决氨基酸饥饿和细胞内酸化。此外，atg22缺失上调一系列应激反应基因的表达，如热休克蛋白家族、细胞壁完整性和自噬。
结论
结果表明Atg22p具有与细胞对Ac抗性相关的新功能。这将有助于我们更深入地了解醋酸诱导的PCD，并为设计木质纤维素生物燃料发酵过程中生产生物乙醇的工业酵母菌株提供一种新的策略，以提高醋酸抗性。
Background
Programmed cell death (PCD) induced by acetic acid, the main by-product released during cellulosic hydrolysis, cast a cloud over lignocellulosic biofuel fermented by Saccharomyces cerevisiae and became a burning problem. Atg22p, an ignored integral membrane protein located in vacuole belongs to autophagy-related genes family; prior study recently reported that it is required for autophagic degradation and efflux of amino acids from vacuole to cytoplasm. It may alleviate the intracellular starvation of nutrition caused by Ac and increase cell tolerance. Therefore, we investigate the role of atg22 in cell death process induced by Ac in which attempt is made to discover new perspectives for better understanding of the mechanisms behind tolerance and more robust industrial strain construction.
Results
In this study, we compared cell growth, physiological changes in the absence and presence of Atg22p under Ac exposure conditions. It is observed that disruption and overexpression of Atg22p delays and enhances acetic acid-induced PCD, respectively. The deletion of Atg22p in S. cerevisiae maintains cell wall integrity, and protects cytomembrane integrity, fluidity and permeability upon Ac stress by changing cytomembrane phospholipids, sterols and fatty acids. More interestingly, atg22 deletion increases intracellular amino acids to aid yeast cells for tackling amino acid starvation and intracellular acidification. Further, atg22 deletion upregulates series of stress response genes expression such as heat shock protein family, cell wall integrity and autophagy.
Conclusions
The findings show that Atg22p possessed the new function related to cell resistance to Ac. This may help us have a deeper understanding of PCD induced by Ac and provide a new strategy to improve Ac resistance in designing industrial yeast strains for bioethanol production during lignocellulosic biofuel fermentation.
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影响因子：
5.3
作者：
通讯作者：
--
影响因子：
6.4
作者：
Mira NP;Palma M;Guerreiro JF;Sá-Correia I
通讯作者：
Sá-Correia I
影响因子：
6.3
作者：
González-Ramos D;Gorter de Vries AR;Grijseels SS;van Berkum MC;Swinnen S;van den Broek M;Nevoigt E;Daran JM;Pronk JT;van Maris AJ
通讯作者：
van Maris AJ
影响因子：
3.2
作者：
OHSUMI, Y;KITAMOTO, K;ANRAKU, Y
通讯作者：
ANRAKU, Y
DOI：
10.15698/mic2014.09.164
发表时间：
2014-08-27
期刊：
Microbial cell (Graz, Austria)
影响因子：
--
作者：
Rego A;Duarte AM;Azevedo F;Sousa MJ;Côrte-Real M;Chaves SR
通讯作者：
Chaves SR