[Transcriptional factor Xanf1 interacts with the focal adhesion protein zyxin in the early development of the Xenopus laevis brain].

We searched for potential protein partners of the homeodomain transcription repressor Xanf1, a key transcriptional regulator of the early development of the forebrain, using a yeast two-hybrid system and identified for the first time the LIM domain protein zyxin from the African clawed frog Xenopus laevis. This protein is interesting because it can play the role of a signal transmitter from cell receptors to the cell nucleus and, thus, participate in the regulation of cell morphogenetic movements and gene expression. The interaction of zyxin with Xanf1 was confirmed by the immunoprecipitation of a complex of endogenous zyxin with the hybrid myc-Xanf1 protein from the lysate of X. laevis embryos. Using a set of deletion mutants of both proteins, we found that binding of the LIM2 domain of zyxin with the Engrailed Homology 1 repressor domain of Xanf1 is responsible for the interaction of these proteins.