Details of Gata-1 Transcriptional Complex Formation  — ASN Events

Details of Gata-1 Transcriptional Complex Formation  (#426)

Lorna E Wilkinson-White 1 , Nina Ripin 2 , David A Jacques 1 , Jacqueline M Matthews 1
  1. Sydney University, NSW, Australia
  2. Institute of Biophysical Chemistry, Goethe University Frankfurt, Frankfurt, Germany

Gata-1 is a key transcription factor in the regulation of haematopoietic development. Gata-1 is associated with either transcriptional activation or repression through its association with a variety of binding partners, including Friend of Gata (FOG) and LIM-only protein 2 (Lmo2). Gata-1 contains two zinc finger domains; the N-finger (NF) and C-finger (CF). The CF binds DNA, whereas the NF is known to bind both protein and DNA. The role of both zinc fingers in DNA binding is of interest given the prevalence of sites in the genome containing two closely spaced GATA-binding motifs. We have used both EMSA and ITC to characterise Gata-1 binding at two dual site motifs, including a consensus sequence identified in a genome-wide screen. We have also structurally characterised the interaction between Gata-1 and the consensus sequence, the first time both Gata-1 zinc fingers have been visualised binding to a dual site on DNA. We observe significantly less contacts between the NF and the DNA relative to the CF, reflecting a weaker interaction. We have also shown that the NF is unable to simultaneously bind Lmo2 and DNA. Therefore it is possible the weaker NF:DNA interaction allows NF to initially contact the DNA, but also to dissociate and thus make the necessary contacts with Lmo2 in order to regulate haematopoiesis.