Serine and threonine phospho-specific antibodies to p120-catenin.

p120-catenin (p120) regulates cadherin turnover and is required for cadherin stability. This role is probably regulated by signaling events that induce p120 phosphorylation, but monitoring individual phosphorylation events and their consequences is technically challenging. Previously, we used phospho-tryptic peptide mapping to identify eight major sites of p120 serine and threonine phosphorylation. Here, we have generated new phospho-specific p120 monoclonal and polyclonal antibodies to phospho-epitopes containing S268, S288, T310, and T910. We have characterized the antibodies with respect to their capabilities and limitations in commonly used assays, including immunoprecipitation (IP), Western blotting (WB), and immunofluorescence (IF). The antibodies should markedly accelerate efforts to delineate the roles of individual p120 modifications and will be particularly useful in identifying upstream signaling events that regulate p120 function.