Seed-specific transcription factors ABI3 and FUS3: molecular interaction with DNA
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In Arabidopsis thaliana (L.) Heynh. the seed-specific transcription factors ABI3 and FUS3 have key regulatory functions during the development of mature seeds. The highly conserved RY motif [DNA motif CATGCA(TG)], present in many seed-specific promoters, is an essential target of both regulators. Here we show that, in vitro, the full-length ABI3 protein, as well as FUS3 protein, is able to bind to RY-DNA and that the B3 domains of both transcription factors are necessary and sufficient for the specific interaction with the RY element. Flanking sequences of the RY motif modulate the binding, but the presence of an RY sequence alone allows the specific interaction of ABI3 and FUS3 with the target in vitro. Transcriptional activity of ABI3 and FUS3, measured by transient promoter activation, requires the B3 DNA-binding domain and an activation domain. In addition to the known N-terminal-located activation domain, a second transcription activation domain was found in the B1 region of ABI3.
KeywordsABI3 Arabidopsis FUS3 Transcription factor DNA binding Transient expression
Abscisic acid insensitive 3
Leafy cotyledon 1 (2)
DNA motif CATGCA(TG)
We are grateful to Barbara Kettig for her excellent help with FPLC, to Sabine Skiebe for skillful handling of the transactivation experiments and to Heike Ernst for graphical support.
- Bäumlein H, Boerjan W, Nagy I, Bassüner R, van Montagu M, Inze D, Wobus U (1991a) A novel seed protein gene from Vicia faba is developmentally regulated in transgenic tobacco and Arabidopsis plants. Mol Gen Genet 22:459–467Google Scholar
- Ezcurra I, Wycliffe P, Nehlin L, Ellerström M, Rask L (2000) Transactivation of the Brassica napus napin promoter by ABI3 requires interaction of the conserved B2 and B3 domains of ABI3 with different cis-elements: B2 mediates activation through an ABRE, whereas B3 interacts with an RY/G-box. Plant J 24:57–66CrossRefPubMedGoogle Scholar
- Goldberg RB, Depaiva G, Yadegari R (1994) Plant embryogenesis—zygote to seed. Science 266:605–614Google Scholar
- Koornneef M, Reuling G, Karssen CM (1984) The isolation and characterization of abscisic acid-insensitive mutants of Arabidopsis thaliana. Plant Physiol 90:463–469Google Scholar
- McCarty DR (1995) Genetic control and integration of maturation and germination pathways in seed development. Annu Rev Plant Physiol Plant Mol Biol 46:71–93Google Scholar
- Müller AJ (1963) Embryonentest zum Nachweis rezessiver Lethalfaktoren bei Arabidopsis thaliana. Biol Zentralbl 83:133–163Google Scholar
- Reidt W (2002) Analysis of transcription factors during late-embryogenesis: the role of FUS3, LEC1, ABI3 and AtET. Thesis, University of Halle, GermanyGoogle Scholar
- Reidt W, Ellerström M, Kölle K, Tewes A, Tiedemann J, Altschmied L, Bäumlein H (2001) FUS3-dependent gene regulation during late embryogenesis. J Plant Physiol 158:411–418Google Scholar