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TOBFAC: The database of tobacco transcription factors

Family: GeBP

Minimum number of tobacco GeBP genes: 15

Count of tobacco GeBP sequences: 16

Pfam accession: DUF573

SHOULD possess DUF573 domain

Trichomes of Arabidopsis are single-celled epidermal hair that are a useful model for studying plant cell fate determination. Trichome initiation requires the activity of the GLABROUS1 (GL1) gene whose expression in epidermal and trichome cells is dependent on the presence of a 3'-cis-regulatory element. Using a one-hybrid screen, we have isolated a cDNA, which encodes for a protein, GL1 enhancer binding protein (GeBP), that binds this regulatory element in yeast and in vitro. GeBP and its three homologues in Arabidopsis share two regions: a central region with no known motifs and a C-terminal region with a putative leucine-zipper motif. We show that both regions are necessary for trans-activation in yeast. A translational fusion with the Yellow Fluorescent Protein (YFP) indicates that GeBP is a nuclear protein whose localization is restricted to, on average, 3-5 subnuclear foci that might correspond to nucleoli. Transcriptional fusion with the GUS reporter indicates that GeBP is mainly expressed in vegetative meristematic tissues and in very young leaf primordia. We looked at GeBP expression in plants mutated in or misexpressing KNAT1, a KNOX gene, expressed in the shoot apical meristem and downregulated in leaf founder cells, and found that GeBP transcript level is regulated by KNAT1 suggesting that KNAT1 is a transcriptional activator of GeBP. This regulation suggests that GeBP is acting as a repressor of leaf cell fate.

Papers

Curaba, J; Herzog, M; Vachon, G. GeBP, the first member of a new gene family in Arabidopsis, encodes a nuclear protein with DNA-binding activity and is regulated by KNAT1. Plant J. 2003. 33(2):305-17 PMID: 12535344

Number of contigs: 15

Number of singlets: 4

Number of N terminal – 1

Number of C terminal – 1

Number of full – 14

Total minimum number – 15

Search sequences and info

Transcription factor sequences

Tobacco published genes related to transcription factor family GeBP

Authors of this site:

Paul J Rushton
Marta T. Bokowiec
Xianfeng (Jeff) Chen
Thomas (Tom) W Laudeman
Jennifer F. Brannock
Michael P. Timko

Contact:

pr8y@virginia.edu