CgCmk1 Activates CgRds2 To Resist Low-pH Stress in Candida glabrata
CgCmk1 Activates CgRds2 To Resist Low-pH Stress in Candida glabrata
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DOI：
10.1128/aem.00302-20
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发表时间：
2020-04
影响因子：
4.4
通讯作者：
Chengjin Wu;Guoxing Zhu;Q. Ding;Pei Zhou;Liming Liu;Xiulai Chen
中科院分区：
文献类型：
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作者：
Chengjin Wu;Guoxing Zhu;Q. Ding;Pei Zhou;Liming Liu;Xiulai Chen
酸性环境是赤霞珠有机酸生产的主要问题。本研究报道钙/钙调素依赖性蛋白激酶CgCmk1正调控CgRds2以增加细胞内ATP含量、膜通透性和对低ph胁迫的抵抗力。因此，转录因子CgRds2可能是提高C. glabrata在有机酸发酵过程中耐酸能力的潜在靶点。本研究还在钙信号通路与能量代谢之间建立了新的联系。在念珠菌中，转录因子CgRds2被认为是甘油磷脂代谢的调节因子，在对渗透胁迫的反应中起着至关重要的作用。在这里，我们报道了CgRds2也参与了对pH 2.0胁迫的响应。在pH 2.0时，CgRDS2的缺失导致细胞生长和存活分别比野生型菌株降低33%和57%。这些不良表型是由于Cgrds2Δ菌株在pH 2.0下与能量代谢相关的基因下调，导致细胞内ATP含量降低34%，膜通透性降低24%。相比之下，过表达CgRDS2挽救了Cgrds2Δ菌株的生长缺陷，在pH 2.0条件下，与野生型菌株相比，细胞存活率提高了17%，同时ATP含量和膜透性也显著增加，分别提高了42%和19%。此外，我们发现钙/钙调素依赖性蛋白激酶（CaMK） CgCmk1与CgRds2的PAS结构域相互作用，并且在pH 2.0胁迫下，CgCmk1是CgRds2活化和从细胞质向细胞核转运所必需的。此外，CgCmk1对CgRds2抵抗pH 2.0胁迫的功能至关重要，因为CgRds2 -pas菌株的细胞在pH 2.0时，CgCmk1-CgRds2相互作用被破坏，细胞的能量代谢和膜通透性受损。因此，我们的研究结果表明，CgCmk1正调控CgRds2，表明它们通过增强光棘草的能量代谢和膜通透性来促进对低ph胁迫的抵抗。酸性环境是光棘草生产有机酸的主要问题。本研究报道钙/钙调素依赖性蛋白激酶CgCmk1正调控CgRds2以增加细胞内ATP含量、膜通透性和对低ph胁迫的抵抗力。因此，转录因子CgRds2可能是提高C. glabrata在有机酸发酵过程中耐酸能力的潜在靶点。本研究还在钙信号通路与能量代谢之间建立了新的联系。
An acidic environment is the main problem in the production of organic acids in C. glabrata. The present study reports that the calcium/calmodulin-dependent protein kinase CgCmk1 positively regulates CgRds2 to increase intracellular ATP content, membrane permeability, and resistance to low-pH stress. Hence, the transcription factor CgRds2 may be a potential target for improving the acid stress tolerance of C. glabrata during the fermentation of organic acids. The present study also establishes a new link between the calcium signaling pathway and energy metabolism. ABSTRACT In Candida glabrata, the transcription factor CgRds2 has been previously characterized as a regulator of glycerophospholipid metabolism, playing a crucial role in the response to osmotic stress. Here, we report that CgRds2 is also involved in the response to pH 2.0 stress. At pH 2.0, the deletion of CgRDS2 led to reduced cell growth and survival, by 33% and 57%, respectively, compared with those of the wild-type strain. These adverse phenotypes resulted from the downregulation of genes related to energy metabolism in the Cgrds2Δ strain at pH 2.0, which led to a 34% reduction of the intracellular ATP content and a 24% decrease in membrane permeability. In contrast, the overexpression of CgRDS2 rescued the growth defect of the Cgrds2Δ strain and increased cell survival at pH 2.0 by 17% compared with that of the wild-type strain, and this effect was accompanied by significant increases in ATP content and membrane permeability, by 42% and 19%, respectively. Furthermore, we found that the calcium/calmodulin-dependent protein kinase (CaMK) CgCmk1 physically interacts with the PAS domain of CgRds2, and CgCmk1 is required for CgRds2 activation and translocation from the cytoplasm to the nucleus under pH 2.0 stress. Moreover, CgCmk1 is critical for CgRds2 function in resistance to pH 2.0 stress, because cells of the Cgrds2-pas strain with a disrupted CgCmk1-CgRds2 interaction exhibited impaired energy metabolism and membrane permeability at pH 2.0. Therefore, our results indicate that CgCmk1 positively regulates CgRds2 and suggest that they promote resistance to low-pH stress by enhancing energy metabolism and membrane permeability in C. glabrata. IMPORTANCE An acidic environment is the main problem in the production of organic acids in C. glabrata. The present study reports that the calcium/calmodulin-dependent protein kinase CgCmk1 positively regulates CgRds2 to increase intracellular ATP content, membrane permeability, and resistance to low-pH stress. Hence, the transcription factor CgRds2 may be a potential target for improving the acid stress tolerance of C. glabrata during the fermentation of organic acids. The present study also establishes a new link between the calcium signaling pathway and energy metabolism.