Cellulose is a by-product of agricultural production and an abundant waste. As a carbon source, cellulose can be degraded and utilized by fungi. Carbon sources, which act as nutrients, not only provide energy but also serve as regulators of gene expression, metabolism and growth, through various signalling networks that enable cells to sense and adapt to varying environmental conditions. Nutrient-sensing pathways prioritize the use of preferred carbon sources and regulate the production of cellulose-degrading enzymes when necessary. Understanding the regulation of the fungal cellulolytic response will become increasingly important because we strive to increase the efficiency of the utilization of these renewable energy sources. Here, we show that Glsnf1, a sucrose-nonfermenting serine-threonine-protein kinase 1 (Snf1)/AMP-activated protein kinase homologue in medicinal macro basidiomycete Ganoderma lucidum, actively responds to carbon alterations and positively regulates cellulase activity and cellulase-related gene transcription. The carbon catabolite repressor CreA, a zinc binuclear cluster transcription factor that mediates the sensing of nutrients and suppression of the transcription of a number of genes necessary for the consumption of a less preferred carbon source, participates in the Glsnf1-mediated regulation of cellulases. Glsnf1 not only negatively regulates the transcription level of the CreA gene but also hinders its localization in the nucleus. Overall, our findings reveal a key nutrient-sensing mechanism that is critical for the modulation of carbon source adaptation in G. lucidum.

中文翻译：

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在灵芝中，Glsnf1通过抑制纤维素利用过程中的GlCreA来调节纤维素的降解。

纤维素是农业生产和大量废物的副产品。作为碳源，纤维素可以被真菌降解并利用。碳源不仅可以提供营养，还可以通过各种信号传递网络提供能量，同时还可以作为基因表达，代谢和生长的调节剂，使细胞能够感知并适应各种环境条件。营养感应途径优先使用首选碳源，并在必要时调节纤维素降解酶的产生。因为我们努力提高这些可再生能源的利用效率，所以了解真菌纤维素分解反应的调控将变得越来越重要。在这里，我们显示Glsnf1，药用宏观担子菌灵芝中的蔗糖非发酵丝氨酸-苏氨酸蛋白激酶1（Snf1）/ AMP激活的蛋白激酶同源物，对碳的变化做出积极反应并积极调节纤维素酶活性和纤维素酶相关的基因转录。碳分解代谢物阻遏物CreA，一种锌双核簇转录因子，介导营养素的感知并抑制消耗次优选碳源所必需的许多基因的转录，它参与了Glsnf1介导的纤维素酶调控。Glsnf1不仅负调控CreA基因的转录水平，而且阻碍其在细胞核中的定位。总体而言，我们的发现揭示了关键的养分感应机制，这对于灵芝中碳源适应的调节至关重要。