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Zinc finger protein transcription factors (ZFP TFs) have been designed to control the expression of endogenous genes in a variety of cells. However, thus far the use of engineered ZFP TFs in germline transgenic settings has been restricted to plants. Here we report that ZFP TFs can regulate gene expression in transgenic Drosophila. To demonstrate this, we targeted the promoter of the well-characterized fushi tarazu (ftz) gene with a ZFP TF activator using the VP16 activation domain from Herpes simplex virus, and ZFP TF repressors using the Drosophila methyl-CpG binding domain (MBD)-like Delta protein. Heat-shock-inducible expression of the ZFP TF activator and repressors resulted in reciprocal effects on ftz regulation, as deduced from changes in the staining pattern and intensity of ftz and en gene expression, and from the cuticular analysis of first instar larvae. These data demonstrate the utility of ZFP TFs as tools for controlling gene expression in the context of a metazoan organism.

The use of synthetic chemical moieties to design fully functional analogues of transcription factors will give rise to novel molecular tools for targeted gene regulation. Here we demonstrate that a synthetic molecule based on a nonpeptidic DNA-binding domain can be engineered to function as a highly potent transcription factor in vitro and in an intracellular context. The structure of this artificial transcription factor (ATF) consists of three parts: (i) triple-helix-forming oligonucleotide as a DNA-binding domain; (ii) composite linker moiety; and (iii) short synthetic peptide. The direct comparison of ATFs with natural transcription factors in in vitro assays reveals the ability of ATFs to initiate RNA transcription at the correct initiation site. In addition, the transcriptional activation potency of ATFs in vitro matches or exceeds the potency of GAL4-VP16, one of the strongest natural transcriptional activators. This remarkable biological activity is explained as a function of ATF's chemical structure. We also demonstrate for the first time that ATFs possess substantial ability to activate transcription in tissue culture cells, thus opening a prospect for practical applications in basic and applied research. The specific molecular design employed in the synthesis of ATFs may lead to the development of novel gene-targeting pharmaceuticals for treatment of fatal and chronic diseases.