PEP3 overexpression shortens lag phase but does not alter growth rate in Saccharomyces cerevisiae exposed to acetic acid stress.
PEP3 overexpression shortens lag phase but does not alter growth rate in Saccharomyces cerevisiae exposed to acetic acid stress.
复制标题
PEP3 过表达缩短了滞后期，但不改变暴露于乙酸胁迫的酿酒酵母的生长速率。
DOI：
10.1007/s00253-015-6708-9
复制
发表时间：
2015
影响因子：
5
通讯作者：
Bakalinsky,AlanT
中科院分区：
文献类型：
--
作者：
Ding,Jun;Holzwarth,Garrett;Bradford,CSamuel;Cooley,Ben;Yoshinaga,AllenS;Patton-Vogt,Jana;Abeliovich,Hagai;Penner,MichaelH;Bakalinsky,AlanT
在真菌中，两种公认的机制有助于pH稳态：质膜质子泵ATP酶输出过量的质子和液泡质子泵ATP酶（V-ATP酶），介导液泡质子吸收。在这里，我们报告PEP 3的过度表达，其中编码的HOPS和CORVET复合物参与液泡生物合成的组成部分，缩短滞后期在酵母暴露于乙酸胁迫。通过共聚焦显微镜，PEP 3过表达细胞与空泡膜特异性染料，FM 4 -64染色有更多的破碎空泡比野生型对照。通过流式细胞术测定，还发现染色的过表达突变体表现出比野生型对照多约3.6倍的FM 4 -64荧光。虽然在80 mM乙酸存在下生长的野生型菌株的液泡pH显著高于在不存在添加的酸的情况下，但在80 mM乙酸存在或不存在下生长的过表达菌株的液泡pH中没有观察到显著差异。间接生长试验表明，PEP 3过表达菌株具有较高的V-ATPase活性。我们推测PEP 3过表达通过增加液泡表面积和V-ATP酶活性，从而增加质子螯合能力，从而提供对酸胁迫的保护。
In fungi, two recognized mechanisms contribute to pH homeostasis: the plasma membrane proton-pumping ATPase that exports excess protons and the vacuolar proton-pumping ATPase (V-ATPase) that mediates vacuolar proton uptake. Here, we report that overexpression ofPEP3which encodes a component of the HOPS and CORVET complexes involved in vacuolar biogenesis, shortened lag phase inSaccharomyces cerevisiaeexposed to acetic acid stress. By confocal microscopy,PEP3-overexpressing cells stained with the vacuolar membrane-specific dye, FM4-64 had more fragmented vacuoles than the wild-type control. The stained overexpression mutant was also found to exhibit about 3.6-fold more FM4-64 fluorescence than the wild-type control as determined by flow cytometry. While the vacuolar pH of the wild-type strain grown in the presence of 80 mM acetic acid was significantly higher than in the absence of added acid, no significant difference was observed in vacuolar pH of the overexpression strain grown either in the presence or absence of 80 mM acetic acid. Based on an indirect growth assay, thePEP3-overexpression strain exhibited higher V-ATPase activity. We hypothesize thatPEP3overexpression provides protection from acid stress by increasing vacuolar surface area and V-ATPase activity and, hence, proton-sequestering capacity.