Structural basis of interaction between protein tyrosine phosphatase PCP-2 and β-catenin

PCP-2 is a member of receptor-like protein tyrosine phosphatase of the MAM domain family. To investigate which part of PCP-2 was involved in its interaction with β-catenin, we constructed various deletion mutants of PCP-2. These PCP-2 mutants and wild-type PCP-2 were co-transfected into BHK-21 cells with β-catenin individually. Anin vivo binding assay revealed that the expression of wild-type PCP-2, PCP-2 ΔC1C2 (deleted PCP-2 without both PTP domains) and PCP-2 ΔC2 (deleted PCP-2 without the second PTP domain) could be immunoprecipitated by anti-catenin antibody in every co-transfection, but PCP-2 EXT (deleted PCP-2 without the juxtamembrane region and both PTP domains) was missing, which implied that PCP-2 and β-catenin could associate directly and the juxtamembrane region in PCP-2 was sufficient for the process.