Interaction partners of the PDZ domain of erbin.

In order to identify proteins that bind to the PDZ domain of Erbin, we tested the C-termini of several proteins in a yeast two-hybrid assay. ErbB2, APC, beta-catenin, c-Rel and HTLV-1 Tax were identified as ligands of the PDZ domain of Erbin. The interactions were verified by co-immunoprecipitation experiments.

Bcr interferes with beta-catenin-Tcf1 interaction.

The beta-catenin/Tcf complex is a downstream effector of the Wnt signalling pathway. It is a transcription complex, which activates gene expression and contributes to proliferation and tumor progression. Tcf1 in complex with beta-catenin is able to activate beta-catenin-dependent gene expression.

Bcr is a negative regulator of the Wnt signalling pathway.

The Wnt signalling pathway can activate transcription of genes such as c-myc through beta-catenin. Here, we describe the protein breakpoint cluster region, Bcr, as a negative regulator of this pathway. Bcr can form a complex with beta-catenin and negatively regulate expression of c-Myc.