Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China.
Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, China.
Appl Environ Microbiol. 2024 Feb 21;90(2):e0174023. doi: 10.1128/aem.01740-23. Epub 2024 Jan 9.
() is one of the most popular cell factories for expressing exogenous proteins and producing useful chemicals. The alcohol oxidase 1 promoter (P) is the most commonly used strong promoter in and has the characteristic of biphasic expression. However, the inducer for P, methanol, has toxicity and poses risks in industrial settings. In the present study, analyzing transcriptomic data of cells collected at different stages of growth found that the formate dehydrogenase (FDH) gene ranked 4960th in relative expression among 5032 genes during the early logarithmic growth phase but rose to the 10th and 1st during the middle and late logarithmic growth phases, respectively, displaying a strict biphasic expression characteristic. The unique transcriptional regulatory profile of the FDH gene prompted us to investigate the properties of its promoter (P). Under single-copy conditions, when a green fluorescent protein variant was used as the expression target, the P achieved 119% and 69% of the activity of the glyceraldehyde-3-phosphate dehydrogenase promoter and P, respectively. After increasing the copy number of the expression cassette in the strain to approximately four copies, the expression level of GFPuv driven by P increased to approximately 2.5 times that of the strain containing GFPuv driven by a single copy of P. Our P-based expression system exhibited precise biphasic expression, ease of construction, minimal impact on normal cellular metabolism, and high strength. Therefore, it has the potential to serve as a new expression system to replace the P promoter.IMPORTANCEThe alcohol oxidase 1 promoter (PAOX1) expression system has the characteristics of biphasic expression and high expression levels, making it the most widely used promoter in the yeast . However, PAOX1 requires methanol induction, which can be toxic and poses a fire hazard in large quantities. Our research has found that the activity of PFDH800 is closely related to the growth state of cells and can achieve biphasic expression without the need for an inducer. Compared to other reported non-methanol-induced biphasic expression systems, the system based on the PFDH800 offers several advantages, including high expression levels, simple construction, minimal impact on cellular metabolism, no need for an inducer, and the ability to fine-tune expression.
()是表达外源蛋白和生产有用化学品的最受欢迎的细胞工厂之一。醇氧化酶 1 启动子(P)是中最常用的强启动子,具有两相表达的特点。然而,P 的诱导剂甲醇具有毒性,在工业环境中存在风险。在本研究中,分析不同生长阶段细胞的转录组数据发现,甲酸脱氢酶(FDH)基因在对数早期生长阶段的 5032 个基因中相对表达排名第 4960 位,但在对数中期和晚期分别上升到第 10 位和第 1 位,表现出严格的两相表达特征。FDH 基因独特的转录调控谱促使我们研究其启动子(P)的性质。在单拷贝条件下,当绿色荧光蛋白变体作为表达靶标时,P 的活性分别达到甘油醛-3-磷酸脱氢酶启动子和 P 的 119%和 69%。在菌株中表达盒的拷贝数增加到大约四个拷贝后,由 P 驱动的 GFPuv 的表达水平增加到大约 2.5 倍,而由 P 驱动的单个拷贝的 GFPuv 的表达水平。我们基于 P 的表达系统表现出精确的两相表达、易于构建、对正常细胞代谢的影响最小和高强度。因此,它有可能取代 P 启动子成为新的表达系统。
重要性:醇氧化酶 1 启动子(PAOX1)表达系统具有两相表达和高表达水平的特点,使其成为酵母中应用最广泛的启动子。然而,PAOX1 需要甲醇诱导,甲醇在大量存在时可能有毒且有火灾隐患。我们的研究发现,PFDH800 的活性与细胞的生长状态密切相关,可以在不需要诱导剂的情况下实现两相表达。与其他报道的非甲醇诱导的两相表达系统相比,基于 PFDH800 的系统具有几个优点,包括高表达水平、简单的构建、对细胞代谢的影响最小、不需要诱导剂以及可以精细调节表达。