title: Elevation of seed alpha-tocopherol levels using plant-based transcription factors targeted to an endogenous locus.
abstract: Synthetic zinc finger transcription factors (ZFP-TFs) were designed to upregulate the expression of the endogenous Arabidopsis gamma-tocopherol methyltransferase (GMT) gene. This gene encodes the enzyme responsible for the conversion of gamma-tocopherol to alpha-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 alpha-tocopherol. These results demonstrate that engineered ZFP-TFs comprised of plant-derived elements are capable of modulating the expression of endogenous genes in plants.
authors.affiliation: Monsanto Company, 1920 5th Street, Davis, CA 95616, USA.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Van Eenennaam
authors.forename: Guofu
authors.initials: G
authors.lastname: Li
authors.forename: Mylavarapu
authors.initials: M
authors.lastname: Venkatramesh
authors.forename: Charlene
authors.initials: C
authors.lastname: Levering
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Gong
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Jamieson
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Rebar
authors.forename: Christine K
authors.initials: CK
authors.lastname: Shewmaker
authors.forename: Casey C
authors.initials: CC
authors.lastname: Case
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D018390:Gene Targeting / Q000379:methods; D024861:Genetic Enhancement / Q000379:methods; D005819:Genetic Markers; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000378:metabolism; D015202:Protein Engineering / Q000379:methods; D011994:Recombinant Proteins / Q000378:metabolism; D012639:Seeds / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000502:physiology; D016335:Zinc Fingers / Q000235:genetics; D024502:alpha-Tocopherol / Q000378:metabolism*
chemical_list: D005819:Genetic Markers; D011994:Recombinant Proteins; D014157:Transcription Factors; D008780:Methyltransferases; C047259:gamma-tocopherol methyltransferase; D024502:alpha-Tocopherol