BBR-BPC Genomic sequences

Minimum number of tobacco BBR-BPC genes: 3

Count of tobacco BBR-BPC sequences: 3

Pfam accession: DUF1004

SHOULD possess DUF1004 domain

This family includes gbp a protein from Soybean that binds to GAGA element dinucleotide repeat DNA. It seems likely that the this domain mediates DNA binding. This putative domain contains several conserved cysteines and a histidine suggesting this may be a zinc-binding DNA interaction domain.

The barley b recombinant (BBR) protein binds specifically to the (GA/TC)8 repeat. BBR is nuclear targeted and is a characterized nuclear localization signal (NLS) sequence, a DNA-binding domain extended up to 90 aa at the C-terminus and a putative N-terminal activation domain. The corresponding gene has no introns and is ubiquitously expressed in barley tissues. In co-transfection experiments, BBR activates (GA/TC)8-containing promoters, and its overexpression in tobacco leads to a pronounced leaf shape modification. BBR has properties of a GAGA-binding factor, but the corresponding gene has no sequence homology to Trl and Psq of Drosophila, which encode functionally analogous proteins.

We identified BASIC PENTACYSTEINE1 (BPC1) as a regulator of the homeotic Arabidopsis thaliana gene SEEDSTICK (STK), which con trols ovule identity, and characterized its mechanism of action. A combination of tethered particle motion analysis and elect romobility shift assays revealed that BPC1 is able to induce conformational changes by cooperative binding to purine-rich ele ments present in the STK regulatory sequence. Analysis of STK expression in the bpc1 mutant showed that STK is upregulated. O ur results give insight into the regulation of gene expression in plants and provide the basis for further studies to underst and the mechanisms that control ovule identity in Arabidopsis. In the dominant mutant Hooded (K), the barley gene BKn3 is overexpressed as a result of a duplication of 305 bp in intron IV. When fused to a cauliflower mosaic virus 35S minimal promoter, the 305 bp element activates gene expression in tobacco, as d oes a 655 bp BKn3 promoter sequence. Both DNA fragments contain a (GA)8 repeat (GA/TC)8. A one-hybrid screen using the 305 bp element as the DNA target led to the cloning of the barley b recombinant (BBR) protein, which binds specifically to the (GA/ TC)8 repeat. BBR is nuclear targeted and is a characterized nuclear localization signal (NLS) sequence, a DNA-binding domain extended up to 90 aa at the C-terminus and a putative N-terminal activation domain. The corresponding gene has no introns and is ubiquitously expressed in barley tissues. In co-transfection experiments, BBR activates (GA/TC)8-containing promoters, an d its overexpression in tobacco leads to a pronounced leaf shape modification. BBR has properties of a GAGA-binding factor, b ut the corresponding gene has no sequence homology to Trl and Psq of Drosophila, which encode functionally analogous proteins. In Arabidopsis, (GA/TC)8 repeats occur particularly within 1500 bp upstream of gene start codons included in some homeodoma in genes of different classes. The data presented suggest that expression of the barley BKn3 is regulated, at least in part, by the binding of the transcription factor BBR to GA/TC repeats

Papers

Kooiker M, Airoldi CA, Losa A, Manzotti PS, Finzi L, Kater MM, Colombo L. BASIC PENTACYSTEINE1, a GA binding protein that induces conformational changes in the regulatory region of the homeotic Arabidopsis gene SEEDSTICK. Plant Cell. 2005 Mar;17(3):722-9. Epub 2005 Feb 18. PMID: 15722463

Santi L, Wang Y, Stile MR, Berendzen K, Wanke D, Roig C, Pozzi C, Muller K, Muller J, Rohde W, Salamini F. The GA octodinucleotide repeat binding factor BBR participates in the transcriptional regulation of the homeobox gene Bkn3. Plant J. 2003 Jun;34(6):813-26. PMID: 12795701



Number of contigs : 1

Number of singlets: 3

Full – 3

Total minimum number – 3




Search sequences and info


Transcription factor sequences
Locus
Description
NCBI
BBR-BPC_1 [comment=full] ET050385
ET043770
ET047354
BBR-BPC_3 [comment=full] ET042975
BBR-BPC_4 [comment=almost full (missing first 15 amino acids)] ET041675


Tobacco published genes related to transcription factor family BBR-BPC
Family Genbank ID Name
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