酿酒酵母中苜蓿源诱导型转录调控工具的构建与应用

Construction and application of an inducible transcriptional regulatory tool fromMedicago truncatulain Saccharomyces cerevisiae

摘要:

基于转录因子的转录调控是广泛应用于微生物细胞工厂的一种有效的调控方式。目前，已实现应用的酿酒酵母内源天然转录调控元件较少，且存在基础表达高或动态范围窄等问题，无法满足异源化合物的特定代谢调控需求。植物中含有丰富的转录调控元件，但大多元件的序列和功能尚未充分表征和优化，在微生物细胞工厂中的应用更是处于初级阶段。本研究选取了蒺藜苜蓿中天然调控元件，包括转录因子MtTASR2和MtTASR3以及其结合的启动子P_roHMGR1，对其进行功能表征和工程化改造，构建了诱导型转录调控工具，并将其应用于酿酒酵母中β-胡萝卜素异源合成途径的特异性调控，使β-胡萝卜素产量相比出发菌株提高7.31倍。本研究进一步证明了植物源转录调控元件可用于调节酿酒酵母中基因的表达，为其在微生物细胞工厂中的特异性调控和应用提供了新的策略和思路。

Abstract:

Transcriptional regulation based on transcription factors is an effective regulatory method widely used in microbial cell factories. Currently, few naturally transcriptional regulatory elements have been discovered from Saccharomyces cerevisiae and applied. Moreover, the discovered elements cannot meet the demand for specific metabolic regulation of exogenous compounds due to the high background expression or narrow dynamic ranges. There are abundant transcriptional regulatory elements in plants. However, the sequences and functions of most elements have not been fully characterized and optimized. Particularly, the applications of these elements in microbial cell factories are still in the infancy stage. In this study, natural regulatory elements from Medicago truncatula were selected, including the transcription factors MtTASR2 and MtTASR3, along with their associated promoter P_roHMGR1, for functional characterization and engineering modification. We constructed an inducible transcriptional regulation tool and applied it in the regulation of heterologous β-carotene synthesis in S.cerevisiae, which increased the β-carotene production by 7.31 folds compared with the original strain. This study demonstrates that plant-derived transcriptional regulatory elements can be used to regulate the expression of multiple genes in S.cerevisiae, providing new strategies and ideas for the specific regulation and application of these elements in microbial cell factories.