GIF Transcription Factor Family
The C-terminal region of GRF transcription factors has transactivation activity. A
search for partner proteins for GRF1 led to the isolation of a GRF-interacting factor
(GIF). Sequence and molecular analysis showed that GIF1 is a functional homolog of the
human SYT transcription coactivator. The N-terminal region of GIF1 protein is involved
in the interaction with GRF1. To understand the biological function of GIF1, a
loss-of-function mutant of GIF1 was isolated and transgenic plants with GIF1-specific
RNA interference were constructed. Like grf mutants, the gif1 mutant and transgenic
plants developed narrower leaves and petals than did wild-type plants, and combinations
of gif1 and grf mutations showed a cooperative effect. The narrow leaf phenotype of
gif1, as well as that of the grf triple mutant, was caused by a reduction in cell
numbers along the leaf-width axis. It was proposed that GRF1 and GIF1 act as
transcription activator and coactivator, respectively, and that they are part of a
complex involved in regulating the growth and shape of leaves and petals.
Notes: GIF is missed in PlnTFDB.
20 predicted putative GIF TF peptide,
CDS, cDNA sequences;
blast HSP, multiple sequence alignment,
and phylogeny tree in
Soy - TFKB.
7 GIF protein
and DNA
sequences with
annotations for soybean in PlantTFDB. Most are partial sequences.
Last updated by Dr. Jeff Chen on
July 15, 2009.
