AbstractsBiology & Animal Science

Gene switches and their applications in eukaryotic systems

by Jing Liang




Institution: University of Illinois – Urbana-Champaign
Department:
Year: 2013
Keywords: gene switch
Record ID: 2023755
Full text PDF: http://hdl.handle.net/2142/44177


Abstract

Gene switches, also known as transcription factors, are important components of genetic circuits, and they have wide utility in synthetic biology, gene therapy, and developmental biology. Small molecule inducible gene switches are especially valuable as they offer an easy way to regulate target genes using an external signal. By combining DNA binding domain, ligand binding domain, and activation domain, chimeric gene switches can be engineered to turn on or off a user-defined target gene or set of genes, in response to a user-defined chemical signal. In this thesis, we will explore some applications of gene switches in eukaryotic systems. First, we report the development of a gene switch that is able to regulate the endogenous VEGF-A expression in mammalian cell. The gene switch is specifically and reversibly controlled by 4,4???-dyhydroxybenzil, a small molecule, non-steroid synthetic ligand, which acts orthogonally in a mammalian system. After optimization of the gene switch architecture, a VEGF-A induction ratio of ~200?? can be achieved in HEK293 cells at micromolar concentrations of DHB. Second, we report the development of a system to assemble a multi-gene pathway and subsequently regulate the entire pathway in yeast using an estradiol gene switch. To demonstrate the utility of the system, we assembled the 5-gene zeaxanthin biosynthetic pathway in a single step and showed the ligand dependent, coordinated expression of all 5 genes as well as the tightly-regulated production of zeaxanthin.