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TOBFAC: The database of tobacco transcription factors

Family: ABI

Minimum number of tobacco ABI3-VP1 genes: 76

Count of tobacco ABI3-VP1 sequences: 94

Pfam accession: B3

SHOULD possess a B3 domain but SHOULD NOT possess AP2 Auxin_resp domains

Suzuki et al. (1997) showed that when expressed and purified as a separate peptide, the B3 domain has a highly cooperative DNA binding activity that is specific for the Sph sequence. They found that the properties of this activity are in compelling agreement with the functional analyses of VP1 and regulatory sequences in the C7 promoter. These results identify a new class of DNA binding proteins, which thus far are known only in the plant kingdom, that have critical functions in development .

ABI3/VP1 proteins are members of a large group of transcription factors which act as intermediaries in regulating abscisic acid (ABA)-responsive genes during seed development. Lesions in the genes affect the later stages of seed development and have adverse effects on many important processes such as reserve deposition, dormancy imposition and the acquisition of a tolerance of seed tissues to desiccation. ABI3 does not act in isolation to control gene expression central to seed maturation programmes, but rather acts in concert with various other transcription factors such as LEC1, LEC2 and FUS3; these interactions prevent the precocious activation of genes associated with germination and growth . Maize (Zea mays) Viviparous1 (VP1) and Arabidopsis ABI3 are orthologous transcription factors.

ABI3/VP1 is a multidomain transcription factor that functions as both an activator and a repressor depending on the promoter context . Three basic protein domains, B1, B2, and B3, are highly conserved among ABI3/VP1 factors from various plant species. The C-terminal B3 domain of VP1 binds specifically to the Sph DNA element in the maize C1 promoter, whereas the N-terminal B1 and B2 domains are implicated in nuclear localization and interactions with other proteins. The N-terminal co-activation repression domain is necessary and sufficient for ABA-dependent co-activation functions and repressor activities of VP1/ABI3, whereas the C-terminal B3 is required for a discrete subset of gene activation functions. Recent genetic analysis of abi3 alleles has revealed further complexity of the role of ABI3 in ABA signaling, suggesting that multiple ABA-signaling pathways are perceived through ABI3. Moreover, modification of chromatin structure by PvALF, the Phaseolus sp. ABI3 ortholog, has been shown, suggesting that VP1/ABI3 has a potential to recruit additional DNA-binding proteins to promoters

Papers

Nag, R; Maity, MK; Dasgupta, M. Dual DNA binding property of ABA insensitive 3 like factors targeted to promoters responsive to ABA and auxin. Plant Mol. Biol. 2005. 59(5):821-38 PMID: 16270233

Suzuki, M; Kao, CY; McCarty, DR. The conserved B3 domain of VIVIPAROUS1 has a cooperative DNA binding activity. Plant Cell 1997. 9(5):799-807 PMID: 9165754

Lazarova G, Zeng Y, Kermode AR. Cloning and expression of an ABSCISIC ACID-INSENSITIVE 3 (ABI3) gene homologue of yellow-cedar. J Exp Bot. 2002 May;53(371):1219-21. PMID: 11971933

Suzuki M, Ketterling MG, Li QB, McCarty DR. Viviparous1 alters global gene expression patterns through regulation of abscisic acid signaling. Plant Physiol. 2003 Jul;132(3):1664-77. PMID: 12857845

Number of contigs: 66

Number of singlets: 30

Number of N terminal – 1

Number of C terminal – 17

Number of genes with missing N terminal part – 17

Number of genes with missing C terminal part – 2

Number of middle bits – 14

Number of full – 40

Total minimum number – 76

Search sequences and info

Transcription factor sequences

Tobacco published genes related to transcription factor family ABI

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