BES Transcription Factor Family
This group of proteins contains members of the BZR1/LAT61 family of plant transcriptional repressors involved in controlling
the response to Brassinosteroids (BRs). BRs are plant hormones that play essential roles in growth and development. BZR1
binds directly to DNA repressing the synthesis of genes involved in BR synthesis. Phosphorylation of BZR1 by BIN1 targets
BZR1 to the 20S proteosome, while dephosphorylation leads to nuclear accumulation of BZR1.
Brassinosteroids (BRs) signal through a plasma membrane-localized receptor kinase to regulate plant growth and development.
We showed previously that a novel protein, BES1(BRI1-EMS-SUPPRESSOR 1), accumulates in the nucleus in response to BRs, where
it plays a role in BR-regulated gene expression; however, the mechanism by which BES1 regulates gene expression is unknown.
In this study, we dissect BES1 subdomains and establish that BES1 is a transcription factor that binds to and activates BR
target gene promoters both in vitro and in vivo. BES1 interacts with a basic helix-loop-helix protein, BIM1, to
synergistically bind to E box (CANNTG) sequences present in many BR-induced promoters. Loss-of-function and gain-of-function
mutants of BIM1 and its close family members display BR response phenotypes. Thus, BES1 defines a new class of
plant-specific transcription factors that cooperate with transcription factors such as BIM1 to regulate BR-induced genes.
20 predicted BES TF peptide,
CDS, and cDNA sequences;
blast HSP, and multiple sequence alignment.
20 DUF822 domain peptide sequences with alignment
and domain based phylogeny tree.
7 BES protein
and DNA
sequences with
annotations for soybean in PlantTFDB. Most are partial sequences.
Last updated by Dr. Jeff Chen on
June 7, 2009.
