文献类型： 外文期刊

第一作者： Li, Jinyang

作者： Li, Jinyang;Wang, Xiao;Zou, Jiahuan;Yang, Kun;Wang, Xiaolu;Wang, Yuan;Zhang, Honglian;Huang, Huoqing;Su, Xiaoyun;Yao, Bin;Luo, Huiying;Qin, Xing

作者机构：

关键词： Acidomyces richmondensis MEY-1; copper resistance; transcription factor; metallothionein; gene editing

期刊名称：APPLIED AND ENVIRONMENTAL MICROBIOLOGY （ 影响因子：4.4； 五年影响因子：5.0 ）

ISSN： 0099-2240

年卷期： 2023 年 89 卷 3 期

页码：

收录情况： SCI

摘要： Filamentous fungi are widely distributed worldwide and play an important ecological role as decomposers. However, the mechanisms of their adaptability to various environments are not fully understood. Copper (Cu) homeostasis has not been well documented in filamentous fungi, especially extremophiles. One of the main obstacles impeding their characterization is the lack of a powerful genome-editing tool. In this study, we applied a CRISPR/Cas9 system for efficient targeted gene disruption in the acidophilic fungus Acidomyces richmondensis MEY-1, formerly known as Bispora sp. strain MEY-1. Using this system, we investigated the basis of Cu tolerance in strain MEY-1. This strain has extremely high Cu tolerance among filamentous fungi, and the transcription factor ArAceA (A. richmondensis AceA) has been shown to be involved in this process. The ArAceA deletion mutant (Delta ArAceA) exhibits specific growth defects at Cu concentrations of >= 10 mM and is transcriptionally more sensitive to Cu than the wild-type strain. In addition, the putative metallothionein ArCrdA was involved in Cu tolerance only under high Cu concentrations. MEY-1 has no Aspergillus nidulans CrpA homologs, which are targets of AceA-like transcription factors and play a role in Cu tolerance. Instead, we identified the Cu-transporting P-type ATPase ArYgA, homologous to A. nidulans YgA, which was involved in pigmentation rather than Cu tolerance. When the Delta ArYgA mutant was grown on medium supplemented with Cu ions, the black color was completely restored. The lack of CrpA homologs in A. richmondensis MEY-1 and its high tolerance to Cu suggest that a novel Cu detoxification mechanism differing from the AceA-CrpA axis exists.IMPORTANCE Filamentous fungi are widely distributed worldwide and play an important ecological role as decomposers. However, the mechanisms of their adaptability to various environments are not fully understood. Various extremely acidophilic filamentous fungi have been isolated from acidic mine drainage (AMD) with extremely low pH and high heavy metal and sulfate concentrations, including A. richmondensis. The lack of genetic engineering tools, particularly genome-editing tools, hinders the study of these acidophilic and heavy metal-resistant fungi at the molecular level. Here, we first applied a CRISPR/Cas9-mediated gene-editing system to A. richmondensis MEY-1. Using this system, we identified and characterized the determinants of Cu resistance in A. richmondensis MEY-1. The conserved roles of the Cu-binding transcription factor ArAceA in Cu tolerance and the Cu-transporting P-type ATPase ArYgA in the Cu-dependent production of pigment were confirmed. Our findings provide insights into the molecular basis of Cu tolerance in the acidophilic fungus A. richmondensis MEY-1. Furthermore, the CRISPR/Cas9 system used here would be a powerful tool for studies of the mechanisms of adaptability of acidophilic fungi to extreme environments.

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