title: The flowering time regulator CONSTANS is recruited to the FLOWERING LOCUS T promoter via a unique cis-element.
abstract: CONSTANS is an evolutionarily-conserved central component of the genetic pathway that controls the onset of flowering in response to daylength. However, the specific biochemical mechanism by which the CONSTANS protein regulates the expression of its target genes remains largely unknown. *By using a combination of cell-based expression analysis and in vitro DNA binding studies, we have demonstrated that CONSTANS possesses transcriptional activation potential and is capable of directly binding to DNA. *CONSTANS was found to bind DNA via a unique sequence element containing a consensus TGTG(N2-3)ATG motif. This element is present in tandem within the FLOWERING LOCUS T promoter and is sufficient for CO binding and activity. The conserved CCT (CONSTANS, CONSTANS-like and TOC1) domain of CONSTANS was shown to be required for its recruitment to the DNA motif and other CCT-containing proteins were also found to have the ability to regulate gene expression via this element. *The CCAAT box, which has been previously hypothesized as a recruitment site for complexes containing the CONSTANS protein, potentiated CONSTANS-mediated activation but was not essential for CONSTANS recruitment to a target promoter or for its activity as a transcriptional factor.
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Shiv B
authors.initials: SB
authors.lastname: Tiwari
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Han-Chang
authors.initials: HC
authors.lastname: Chang
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Harris
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Siu Fong
authors.initials: SF
authors.lastname: Ma
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: McPartland
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Hymus
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Luc
authors.initials: L
authors.lastname: Adam
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Colleen
authors.initials: C
authors.lastname: Marion
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Alemu
authors.initials: A
authors.lastname: Belachew
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Repetti
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: T Lynne
authors.initials: TL
authors.lastname: Reuber
authors.affiliation: Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Ratcliffe
mesh_terms: D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D035264:Flowers / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D005973:Glutamine / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020218:Response Elements / Q000235:genetics; D013997:Time Factors; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D004268:DNA-Binding Proteins; C418905:FT protein, Arabidopsis; D014157:Transcription Factors; D005973:Glutamine
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