title: The AtMYB12 activation domain maps to a short C-terminal region of the transcription factor.
abstract: The Arabidopsis thaliana R2R3-MYB transcription factor MYB12 is a light-inducible, flavonol-specific activator of flavonoid biosynthesis. The transactivation activity of the AtMYB12 protein was analyzed using a C-terminal deletion series in a transient A. thaliana protoplast assay with the goal of mapping the activation domain (AD). Although the deletion of the last 46 C-terminal amino acids did not affect the activation capacity, the deletion of the last 98 amino acids almost totally abolished transactivation of two different target promoters. A domain swap experiment using the yeast GAL4 DNA-binding domain revealed that the region from positions 282 to 328 of AtMYB12 was sufficient for transactivation. In contrast to the R2R3-MYB ADs known thus far, that of AtMYB12 is not located at the rearmost C-terminal end of the protein. The AtMYB12 AD is conserved in other experimentally proven R2R3-MYB flavonol regulators from different species.
authors.affiliation: Bielefeld University, Chair of Genome Research, 33615 Bielefeld, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Stracke
authors.affiliation: Istanbul University, Faculty of Science, Department of Molecular Biology and Genetics, 34134 Vezneciler, Istanbul, Turkey.
authors.forename: Neslihan
authors.initials: N
authors.lastname: Turgut-Kara
authors.affiliation: Bielefeld University, Chair of Genome Research, 33615 Bielefeld, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Weisshaar
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D005419:Flavonoids / Q000096:biosynthesis; D018506:Gene Expression Regulation, Plant; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011523:Protoplasts / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D029681:Arabidopsis Proteins; D005419:Flavonoids; C504539:MYB12 protein, Arabidopsis; D014157:Transcription Factors; D005966:Glucuronidase
keywords: MYB12; activation domain; flavonol regulator; production of flavonol glycosides; transcription factor