Oncoprotein Pbx1 is a Hox co-factor

We discovered the Pbx1 proto-oncogene at the site of chromosomal translocations in pediatric leukemias.  We have shown that Pbx homeodomain proteins function as DNA binding partners for a broad class of Hox proteins.  Interactions with Pbx markedly enhance the typically low DNA binding affinities and specificities of these Hox proteins.  We have shown that dimerization with Pbx is mediated by a highly conserved tryptophan motif whose contact with a conserved pocket in the Pbx homeodomain has been elucidated by the crystal structure of the HoxB1-Pbx1 complex bound to DNA.  Oncogenic forms of Pbx1 retain their ability to interact with Hox proteins.

[Links to some of our publications on these topics]