Overexpression of the transcription factor HAC1 improves nerolidol production in engineered yeast
Overexpression of the transcription factor HAC1 improves nerolidol production in engineered yeast
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DOI：
10.1016/j.enzmictec.2019.109485
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发表时间：
2020-03-01
影响因子：
3.4
通讯作者：
Sun, Jie
中科院分区：
文献类型：
--
作者：
Qu, Zhenzhen;Zhang, Lili;Sun, Jie
增加甲戊酸途径的代谢通量，减少竞争途径的代谢通量，利用GAL启动子构建的二异体诱导系统是酵母代谢工程生产萜类化合物的常用策略。利用这些策略，我们构建了一系列具有甲戊酸途径的酵母菌株，最终在摇瓶中生产了336.5 mg/L橙花醇。剪接的HAC1mRNA检测表明，我们构建的菌株发生了未折叠蛋白反应(UPR)。UPR菌株具有较低的GAL1启动子转录活性。HAC1高表达菌株在摇瓶发酵72h时，GAL1启动子的转录活性显著增强。HAC1过表达还使橙花醇滴度提高了47.7%，达到497.0 mg/L，细胞活力增强。RNA-seq结果表明，HAC1过表达的转录应答基因参与了单羧酸代谢过程和细胞氨基酸生物合成过程的调控，表明代谢调控可能是橙花醇合成增加的部分原因。我们的发现丰富了倍半萜生产细胞工厂的建设与UPR调控之间的关系的认识。本研究为酵母生产倍半萜提供了一种有效的策略。
Increasing the metabolic flux of the mevalonate pathway, reducing the metabolic flux of competing pathway and utilizing the diauxie-inducible system constructed by GAL promoters are strategies commonly used in yeast metabolic engineering for the production of terpenoids. Using these strategies, we constructed a series of yeast strains with a strengthened mevalonate pathway and finally produced 336.5 mg/L nerolidol in a shake flask. The spliced HAC1 mRNA assay indicated that the unfolded protein response (UPR) occurred in the strains that we constructed. UPR strains exhibited the low transcriptional activities of GAL1 promoter. HAC1-overexpressing strain exhibited dramatically enhanced transcriptional activity of GAL1 promoter at 72 h of fermentation in flasks. HAC1 overexpression also increased the nerolidol titer by 47.7 %, reaching 497.0 mg/L and increased cell vitality. RNA-seq showed that the genes whose transcription responded to HAC1-overexpression were involved in the regulation of monocarboxylic acid metabolic processes and cellular amino acid biosynthetic process, indicating that the metabolic regulation may be part of the reason of the improved nerolidol synthesis. Our findings enrich the knowledge of the relationship between the construction of sesquiterpene-producing cell factories and UPR regulation. This study provides an effective strategy for sesquiterpene production in yeast.