title: Comparative study and identification of potent eukaryotic transcriptional repressors in gene switch systems.
abstract: 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.
authors.affiliation: Laboratory of Molecular Biotechnology, Center for Biotechnology UNIL-EPFL and Institute of Animal Biology, University of Lausanne, 1015, Lausanne, Switzerland.
authors.forename: Markus O
authors.initials: MO
authors.lastname: Imhof
authors.forename: Philippe
authors.initials: P
authors.lastname: Chatellard
authors.forename: Nicolas
authors.initials: N
authors.lastname: Mermod
mesh_terms: D002460:Cell Line; D004269:DNA, Bacterial / Q000235:genetics; D005057:Eukaryotic Cells / Q000502:physiology; D015870:Gene Expression / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D018014:Gene Transfer Techniques; D006801:Humans; D008957:Models, Genetic; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004269:DNA, Bacterial; D012097:Repressor Proteins; D014157:Transcription Factors; C034811:tetracycline resistance-encoding transposon repressor protein