PlantTFDB
Plant Transcription Factor Database
v4.0
Previous version: v1.0, v2.0, v3.0
Brassica rapa
GeBP Family
Species TF ID Description
XP_009102706.1GeBP family protein
XP_009105150.1GeBP family protein
XP_009113119.1GeBP family protein
XP_009113245.1GeBP family protein
XP_009113254.1GeBP family protein
XP_009123373.1GeBP family protein
XP_009123374.1GeBP family protein
XP_009124212.1GeBP family protein
XP_009124451.1GeBP family protein
XP_009124629.1GeBP family protein
XP_009124974.1GeBP family protein
XP_009137503.1GeBP family protein
XP_009138982.1GeBP family protein
XP_009139614.1GeBP family protein
XP_009139615.1GeBP family protein
XP_009139700.1GeBP family protein
XP_009139865.1GeBP family protein
XP_009139867.1GeBP family protein
XP_009140153.1GeBP family protein
XP_009140722.1GeBP family protein
XP_009141579.1GeBP family protein
XP_009141580.1GeBP family protein
XP_009141581.1GeBP family protein
XP_009141582.1GeBP family protein
XP_009144664.1GeBP family protein
XP_009144666.1GeBP family protein
XP_009148484.1GeBP family protein
XP_009151238.1GeBP family protein
GeBP Family Introduction

Understanding the role of transcription factors (TFs) is essential in reconstructing developmental regulatory networks. The plant-specific GeBP TF family of Arabidopsis thaliana (Arabidopsis) comprises 21 members, all of unknown function. A subset of four members, the founding member GeBP and GeBP-like proteins (GPL) 1, 2, and 3, shares a conserved C-terminal domain. Here we report that GeBP/GPL genes represent a newly defined class of leucine-zipper (Leu-zipper) TFs and that they play a redundant role in cytokinin hormone pathway regulation. Specifically, we demonstrate using yeast, in vitro, and split-yellow fluorescent protein in planta assays that GeBP/GPL proteins form homo- and heterodimers through a noncanonical Leu-zipper motif located in the C-terminal domain. A triple loss-of-function mutant of the three most closely related genes gebp gpl1 gpl2 shows a reduced sensitivity to exogenous cytokinins in a subset of cytokinin responses such as senescence and growth, whereas root inhibition is not affected. We find that transcript levels of type-A cytokinin response genes, which are involved in the negative feedback regulation of cytokinin signaling, are higher in the triple mutant. Using a GPL version that acts as a constitutive transcriptional activator, we show that the regulation of Arabidopsis response regulators (ARRs) is mediated by at least one additional, as yet unknown, repressor acting genetically downstream in the GeBP/GPL pathway. Our results indicate that GeBP/GPL genes encode a new class of unconventional Leu-zipper TF proteins and suggest that their role in the cytokinin pathway is to antagonize the negative feedback regulation on ARR genes to trigger the cytokinin response.

Chevalier F, Perazza D, Laporte F, Le Henanff G, Hornitschek P, Bonneville JM, Herzog M, Vachon G
GeBP and GeBP-Like Proteins Are Noncanonical Leucine-Zipper Transcription Factors That Regulate Cytokinin Response in Arabidopsis
Plant Physiol. 2008 Mar;146(3):1142-54.
PMID: 18162594