Mönke Gudrun, Altschmied Lothar, Tewes Annegret, Reidt Wim, Mock Hans-Peter, Bäumlein Helmut, Conrad Udo
Institut für Pflanzengenetik und Kulturpflanzenforschung Gatersleben, Corrensstr.3, 6466 Gatersleben, Germany.
Planta. 2004 May;219(1):158-66. doi: 10.1007/s00425-004-1206-9. Epub 2004 Feb 7.
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.
在拟南芥中，种子特异性转录因子ABI3和FUS3在成熟种子发育过程中具有关键调控功能。许多种子特异性启动子中存在的高度保守的RY基序[DNA基序CATGCA(TG)]是这两种调控因子的重要靶点。我们在此表明，在体外，全长ABI3蛋白以及FUS3蛋白能够与RY-DNA结合，并且这两种转录因子的B3结构域对于与RY元件的特异性相互作用是必要且充分的。RY基序的侧翼序列调节结合，但仅RY序列的存在就允许ABI3和FUS3在体外与靶点进行特异性相互作用。通过瞬时启动子激活测量的ABI3和FUS3的转录活性需要B3 DNA结合结构域和一个激活结构域。除了已知的位于N端的激活结构域之外，在ABI3的B1区域还发现了第二个转录激活结构域。
