Excellent Research Laboratory for Yeast Innovation, School of Bioresources and Technology, Division of Biochemical Technology, King Mongkut's University of Technology Thonburi, Bangkok, Thailand.
Native Honeybee and Pollinator Research Center, King Mongkut's University of Technology Thonburi, Ratchaburi, Thailand.
Yeast. 2024 Jun;41(6):401-417. doi: 10.1002/yea.3940. Epub 2024 May 6.
To develop a cost-effective microbial cell factory for the production of biofuels and biochemicals, an understanding of tolerant mechanisms is vital for the construction of robust host strains. Here, we characterized a new function of a key metabolic transcription factor named Znf1 and its involvement in stress response in Saccharomyces cerevisiae to enhance tolerance to advanced biofuel, isobutanol. RNA-sequencing analysis of the wild-type versus the znf1Δ deletion strains in glucose revealed a new role for transcription factor Znf1 in the pentose phosphate pathway (PPP) and energy generation. The gene expression analysis confirmed that isobutanol induces an adaptive cell response, resulting in activation of ATP1-3 and COX6 expression. These genes were Znf1 targets that belong to the electron transport chain, important to produce ATPs. Znf1 also activated PPP genes, required for the generation of key amino acids, cellular metabolites, and maintenance of NADP/NADPH redox balance. In glucose, Znf1 also mediated the upregulation of valine biosynthetic genes of the Ehrlich pathway, namely ILV3, ILV5, and ARO10, associated with the generation of key intermediates for isobutanol production. Using S. cerevisiae knockout collection strains, cells with deleted transcriptional regulatory gene ZNF1 or its targets displayed hypersensitivity to isobutanol and acid inhibitors; in contrast, overexpression of ZNF1 enhanced cell survival. Thus, the transcription factor Znf1 functions in the maintenance of energy homeostasis and redox balance at various checkpoints of yeast metabolic pathways. It ensures the rapid unwiring of gene transcription in response to toxic products/by-products generated during biofuel production. Importantly, we provide a new approach to enhance strain tolerance during the conversion of glucose to biofuels.
为了开发经济高效的微生物细胞工厂来生产生物燃料和生物化学品，了解耐受机制对于构建稳健的宿主菌株至关重要。在这里，我们描述了一种名为 Znf1 的关键代谢转录因子的新功能及其在酿酒酵母应激反应中的参与，以增强对先进生物燃料异丁醇的耐受性。野生型与 znf1Δ 缺失菌株在葡萄糖中的 RNA-seq 分析揭示了转录因子 Znf1 在戊糖磷酸途径 (PPP) 和能量生成中的新作用。基因表达分析证实，异丁醇诱导适应性细胞反应，导致 ATP1-3 和 COX6 表达激活。这些基因是 Znf1 的靶标，属于电子传递链，对产生 ATPs 很重要。Znf1 还激活了 PPP 基因，这些基因对于产生关键氨基酸、细胞代谢物和维持 NADP/NADPH 氧化还原平衡很重要。在葡萄糖中，Znf1 还介导 Ehrlich 途径的缬氨酸生物合成基因 ILV3、ILV5 和 ARO10 的上调，这些基因与异丁醇生产的关键中间产物的产生有关。利用酿酒酵母敲除基因文库菌株，缺失转录调节基因 ZNF1 或其靶基因的细胞对异丁醇和酸抑制剂表现出敏感性；相比之下，ZNF1 的过表达增强了细胞的存活率。因此，转录因子 Znf1 在酵母代谢途径的各个检查点发挥作用，维持能量稳态和氧化还原平衡。它确保了在生物燃料生产过程中产生有毒产物/副产物时，基因转录的快速解耦。重要的是，我们提供了一种新的方法来增强葡萄糖转化为生物燃料过程中的菌株耐受性。
