Yeast Two-Hybrid Assay Reveals Several Interactors of EphB6 Receptor

EphB6, a kinase-deficient receptor, belongs to the Eph family of receptor tyrosine kinases. It can participate in active cell-to-cell signaling pathways following dimerization with and phosphorylation by EphB1 and possibly other members of the EphB family. EphB6 is a positive prognostic marker in neuroblastoma. The loss of EphB6 expression in melanomas, non-small cell lung carcinomas and breast cancer appears to be associated with a more advanced stage of these cancers. Despite the apparent role for EphB6 in preventing the progression of these cancers, little is known about EphB6- mediated signaling in cancer. We have identified 16 unique proteins that are capable of interacting with the cytoplasmic domain of EphB6 in the yeast two- hybrid assay. Furthermore, the interaction of a subset of these proteins (aldolaseA, dynactin, clusterin, TMEM25 and plekstrin homology domain- containing family B member 1) with EphB6 in mammalian cells was confirmed by employing a co-immunoprecipitation strategy. The identification of these interacting proteins suggests pathways mediated by EphB6.