The flowering time regulator CONSTANS is recruited to the FLOWERING LOCUS T promoter via a unique cis-element.
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.
Tiwari
Shiv B
SB
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Shen
Yu
Y
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Chang
Han-Chang
HC
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Hou
Yanli
Y
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Harris
Amanda
A
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Ma
Siu Fong
SF
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
McPartland
Megan
M
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Hymus
Graham J
GJ
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Adam
Luc
L
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Marion
Colleen
C
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Belachew
Alemu
A
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Repetti
Peter P
PP
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Reuber
T Lynne
TL
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
Ratcliffe
Oliver J
OJ
Mendel Biotechnology Inc., 3935 Point Eden Way, Hayward, CA 94545, USA.
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
D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D004268:DNA-Binding Proteins; C418905:FT protein, Arabidopsis; D014157:Transcription Factors; D005973:Glutamine
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