Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, South Africa.
Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland, South Africa.
Adv Appl Microbiol. 2023;124:1-29. doi: 10.1016/bs.aambs.2023.07.002. Epub 2023 Jul 27.
The transcription of genes in the yeast Saccharomyces cerevisiae is governed by multiple layers of regulatory elements and proteins, cooperating to ensure optimum expression of the final protein product based on the cellular requirements. Promoters have always been regarded as the most important determinant of gene transcription, but introns also play a key role in the expression of intron-encoding genes. Some introns can enhance transcription when introduced either promoter-proximal or embedded in the open reading frame of genes. However, the outcome is seldom predictable, with some introns increasing or decreasing transcription depending on the promoter and reporter gene employed. This chapter provides an overview of the general structure and function of promoters and introns and how they may cooperate during transcription to allow intron-mediated enhancement of gene expression. Since S. cerevisiae is a suitable host for recombinant protein production on a commercial level, stronger and more controllable promoters are in high demand. Enhanced gene expression can be achieved via promoter engineering, which may include introns that increase the efficacy of recombinant expression cassettes. Different models for the role of introns in transcription are briefly discussed to show how these intervening sequences can actively interact with the transcription machinery. Furthermore, recent examples of improved protein production via the introduction of promoter-proximal introns are highlighted to showcase the potential value of intron-mediated enhancement of gene expression.
酵母酿酒酵母中的基因转录受多层次的调控元件和蛋白质控制，这些调控元件和蛋白质协同作用，根据细胞需求确保最终蛋白质产物的最佳表达。启动子一直被认为是基因转录的最重要决定因素，但内含子在内含子编码基因的表达中也起着关键作用。一些内含子可以在引入启动子近端或嵌入基因的开放阅读框时增强转录。然而，结果往往是不可预测的，一些内含子会根据启动子和报告基因的不同而增加或减少转录。本章概述了启动子和内含子的一般结构和功能，以及它们在转录过程中如何协同作用，从而允许内含子介导的基因表达增强。由于酿酒酵母是一种适合商业水平的重组蛋白生产的宿主，因此对更强、更可控的启动子的需求很高。通过启动子工程可以实现增强基因表达，这可能包括增强重组表达盒效力的内含子。简要讨论了内含子在转录中的不同作用模型，以展示这些间隔序列如何与转录机制进行积极的相互作用。此外，还强调了通过引入启动子近端内含子来提高蛋白质产量的最新示例，以展示内含子介导的基因表达增强的潜在价值。
