Imhof Markus O, Chatellard Philippe, Mermod Nicolas
Laboratory of Molecular Biotechnology, Center for Biotechnology UNIL-EPFL and Institute of Animal Biology, University of Lausanne, 1015, Lausanne, Switzerland.
J Biotechnol. 2002 Aug 28;97(3):275-85. doi: 10.1016/s0168-1656(02)00104-9.
In mammalian cells, proper gene regulation is achieved by the complex interplay of transcription factors that activate or repress gene expression by binding to the regulatory regions of target promoters. While transcriptional activators have been extensively characterised and classified into functional groups, relatively little is known about the comparative strength and cell type-specificity of transcriptional repressors. Here, we have compared the ability of a series of eukaryotic repression domains to silence basal and activated transcription. A series of the most potent repression domains was further tested in the context of a gene therapy gene-switch system in various cell types. The results indicate that the analysed repression domains exert varying silencing activities in different promoter contexts. Furthermore, their potential for gene silencing varies also depending on the cellular context. When multimerised within one chimeric repressor protein, particular combinations of repressor domains were found to display synergistic repressing effects and efficient repression in a panel of cell lines. This approach thus allowed the identification of transcriptional repressors that are both potent and versatile in terms of cellular specificity as a basis for gene switch systems.
在哺乳动物细胞中，通过转录因子的复杂相互作用实现适当的基因调控，这些转录因子通过与靶启动子的调控区域结合来激活或抑制基因表达。虽然转录激活因子已被广泛表征并分类为功能组，但对于转录抑制因子的相对强度和细胞类型特异性了解较少。在这里，我们比较了一系列真核抑制结构域沉默基础转录和激活转录的能力。在各种细胞类型的基因治疗基因开关系统中，对一系列最有效的抑制结构域进行了进一步测试。结果表明，所分析的抑制结构域在不同的启动子背景下发挥不同的沉默活性。此外，它们的基因沉默潜力也因细胞背景而异。当在一种嵌合阻遏蛋白中多聚化时，发现阻遏结构域的特定组合在一组细胞系中表现出协同抑制作用和有效抑制。因此，这种方法能够鉴定出在细胞特异性方面既有效又通用的转录抑制因子，作为基因开关系统的基础。
