Purified Mouse Anti-p120 Catenin (pS288)

The membrane associated protein pp120 Src substrate (p120 catenin, p120cas) was identified as a tyrosine kinase substrate that is phosphorylated in Src-transformed cells.  It shares structural similarity with the Drosophila  Armadillo protein and the vertebrate β-catenin and γ-catenin proteins in its 42-amino acid Arm domain.  p120 catenin is localized to the E-Cadherin/catenin cell adhesion complex.  Like β- and γ-catenin, p120 catenin directly associates with the cytoplasmic C-terminus of E-Cadherin via its Arm domain.  It exists as four isoforms that range in size from 90 to 115 kDa.  Expression of these isoforms is heterogeneous in human carcinomas, suggesting that altered expression contributes to malignancy.  Phosphorylation of multiple serine (S252, S268, S288, and S879), and threonine (T310 and T916) residues in p120 catenin may regulate its activity.  The S879 residue is phosphorylated after PKC activation, while the S268 site is dephosphorylated after PKC activation.  The latter residue is phosphorylated in vitro by p160 Rock.  S252 and T310 residues are phosphorylated in vitro by GSK3b.  Thus, p120 catenin function may be regulated in a complex manner through both serine and threonine phosphorylation.

The 17/catenin monoclonal antibody recognizes the phosphorylated S288 in the regulatory domain of p120 catenin.