GSNOR regulates ganoderic acid content in Ganoderma lucidum under heat stress through S-nitrosylation of catalase

Rui Liu,Zhengyan Yang,Xin Chen,Ting Zhu,Mingwen Zhao,Ang Ren,Zi Wang,Hanshou Yu,Liang Shi

doi:10.1038/s42003-021-02988-0

Rui Liu, Zhengyan Yang + Show 7 more

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https://doi.org/10.1038/s42003-021-02988-0

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Abstract

As a master regulator of the balance between NO signaling and protein S-nitrosylation, S-nitrosoglutathione (GSNO) reductase (GSNOR) is involved in various developmental processes and stress responses. However, the proteins and specific sites that can be S-nitrosylated, especially in microorganisms, and the physiological functions of S-nitrosylated proteins remain unclear. Herein, we show that the ganoderic acid (GA) content in GSNOR-silenced (GSNORi) strains is significantly lower (by 25%) than in wild type (WT) under heat stress (HS). Additionally, silencing GSNOR results in an 80% increase in catalase (CAT) activity, which consequently decreases GA accumulation via inhibition of ROS signaling. The mechanism of GSNOR-mediated control of CAT activity may be via protein S-nitrosylation. In support of this possibility, we show that CAT is S-nitrosylated (as shown via recombinant protein in vitro and via GSNORi strains in vivo). Additionally, Cys (cysteine) 401, Cys642 and Cys653 in CAT are S-nitrosylation sites (assayed via mass spectrometry analysis), and Cys401 may play a pivotal role in CAT activity. These findings indicate a mechanism by which GSNOR responds to stress and regulates secondary metabolite content through protein S-nitrosylation. Our results also define a new S-nitrosylation site and the function of an S-nitrosylated protein regulated by GSNOR in microorganisms.

Highlights

A common and convergent feature of numerous biological processes is the production of redox molecules, including reactive oxygen species (ROS) and reactive nitrogen species (RNS), including nitric oxide (NO) and its derivatives, such as S-nitrosothiols (SNOs), peroxynitrite (ONOO−), and higher nitrogen oxides (NOx)[1]
It was observed that knockdown in the GSNORi-11 and GSNORi-12 strains resulted in a significant reduction of approximately 70% in GSNO reductase (GSNOR) activity compared with that in the wild type (WT), Si-control-1, and Si-control-2 strains (Fig. 1a)
The results showed a significantly higher ganoderic acid (GA) content (25%) in the WT strains than in the GSNORsilenced strains under heat stress (HS) conditions (Fig. 1b)

Summary

Introduction

A common and convergent feature of numerous biological processes is the production of redox molecules, including reactive oxygen species (ROS) and reactive nitrogen species (RNS), including nitric oxide (NO) and its derivatives, such as S-nitrosothiols (SNOs), peroxynitrite (ONOO−), and higher nitrogen oxides (NOx)[1]. The formation of an SNO group on cysteine residues of target proteins is called S-nitrosylation[7]. The degree of S-nitrosylation is balanced and regulated by GSNO reductase (GSNOR)[10]. GSNOR has recently received attention for its role in indirectly regulating NO signaling cascades associated with protein S-nitrosylation. Nitrosylation, as a redox-based posttranslational protein modification, may be integral to NO function in a variety of cellular processes. Similar to other posttranslational modifications, S-nitrosylation has important roles in the regulation of protein activity, subcellular localization, and protein–protein interactions across myriad physiological processes[12]. GSNOR plays a crucial role in a large array of physiological and pathological processes by regulating protein S-nitrosylation[7]. GSNOR-mediated protein S-nitrosylation is necessary for immune function, inflammation, development, and cancer progression[13].

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