Figure 4

The Runx-VDR interaction is well conserved between osteichthyan vertebrate species. GST or the indicated GST-Runx2 fusion proteins (1.5 μg) previously bound to 20 μl of glutathione-Sepharose beads were incubated with the recombinant VDR homologue from Homo sapiens (A) or Danio rerio (B). The Danio rerio VDR protein is not recognized by the anti-VDR antibody (not shown) and was therefore tagged with an N-terminal Myc epitope. Precipitated VDR (upper panel) and GST-Runx2 (lower panel) proteins were then detected by Western blotting. (C) The recombinant VDR homologue from Ciona intestinalis (bearing a Myc epitope in its N-terminal) was incubated with GST or the indicated GST fusion proteins (1.5 μg) previously bound to 20 μl of glutathione-Sepharose beads. Precipitated VDR (upper panel) and GST-Runx2 (lower panel) proteins were then detected by Western blotting. Abbreviations: Dr, Danio rerio; Mm, Mus musculus; Hs, Homo sapiens; Ci, Ciona intestinalis. The migration of molecular weight standards is indicated on the left.