Author/Authors :
Van Eenennaam، نويسنده , , Alison L. and Li، نويسنده , , Guofu and Venkatramesh، نويسنده , , Mylavarapu and Levering، نويسنده , , Charlene and Gong، نويسنده , , Xiaosong and Jamieson، نويسنده , , Andrew C. and Rebar، نويسنده , , Edward J. and Shewmaker، نويسنده , , Christine K. and Case، نويسنده , , Casey C.، نويسنده ,
Abstract :
Synthetic zinc finger transcription factors (ZFP-TFs) were designed to upregulate the expression of the endogenous Arabidopsis γ-tocopherol methyltransferase (GMT) gene. This gene encodes the enzyme responsible for the conversion of γ-tocopherol to α-tocopherol, the tocopherol species with the highest vitamin E activity. Five three-finger zinc finger protein (ZFP) DNA binding domains were constructed and proven to bind tightly to 9 bp DNA sequences located in either the promoter or coding region of the GMT gene. When these ZFPs were fused to a nuclear localization signal and the maize C1 activation domain, four of the five resulting ZFP-TFs were able to upregulate the expression of the GMT gene in leaf protoplast transient assays. Seed-specific expression of these ZFP-TFs in transgenic Arabidopsis produced several lines with a heritable elevation in seed α-tocopherol. These results demonstrate that engineered ZFP-TFs comprised of plant-derived elements are capable of modulating the expression of endogenous genes in plants.
