PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Cucumis melo
FAR1 Family
Species TF ID Description
MELO3C007004P1FAR1 family protein
MELO3C015625P1FAR1 family protein
MELO3C016234P1FAR1 family protein
FAR1 Family Introduction

We show that Arabidopsis FHY3 and FAR1, which encode two proteins related to Mutator-like transposases, act together to modulate phyA signaling by directly activating the transcription of FHY1 and FHL, whose products are essential for light-induced phyA nuclear accumulation and subsequent light responses. FHY3 and FAR1 have separable DNA binding and transcriptional activation domains that are highly conserved in Mutator-like transposases. Further, expression of FHY3 and FAR1 is negatively regulated by phyA signaling. We propose that FHY3 and FAR1 represent transcription factors that have been co-opted from an ancient Mutator-like transposase(s) to modulate phyA-signaling homeostasis in higher plants.

We next used a yeast one-hybrid assay to delineate the DNA sequences to which FHY3 and FAR1 bind. GAD-FHY3 or GAD-FAR1 fusion proteins (GAD, GAL4 transcriptional activation domain), but not GAD alone, activated the LacZ reporter genes driven by the FHY1 and FHL promoters. Deletion analysis narrowed down the FHY3/FAR1 binding site to a 39-bp promoter subfragment located on the "a" fragment for both FHY1 and FHL. Notably, these subfragments share a stretch of consensus sequence, 5'-TTCACGCGCC-3'. Mutating the core sequence "CACGCGC" of this motif (m2 and m3 for FHY1, m5 for FHL) abolished the reporter gene activation by both GAD-FHY3 and GAD-FAR1. Mutating the flanking sequences (m1 and m4) did not obviously affect the reporter gene activation by GAD-FAR1, but clearly reduced activation by GAD-FHY3. Thus, "CACGCGC" likely defines a cis-element that confers specific binding for FHY3 and FAR1 and is named FBS for FHY3-FAR1 binding site.

Lin R, Ding L, Casola C, Ripoll DR, Feschotte C, Wang H.
Transposase-derived transcription factors regulate light signaling in Arabidopsis.
Science, 2007. 318(5854): p. 1302-5.
PMID: 18033885