Solubilisation of the armadillo-repeat protein β-catenin using a zwitterionic detergent allows resolution of phosphorylated forms by 2DE.

The Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia.
Electrophoresis (Impact Factor: 3.16). 07/2012; 33(12):1804-13. DOI: 10.1002/elps.201100671
Source: PubMed

ABSTRACT β-catenin is a member of the armadillo repeat family of proteins and has important functions in cell-cell adhesion and Wnt signalling. Different protein species of β-catenin have been shown to exist in the cell and the relative proportions of these species are altered upon stimulation of cells with Wnt-3a (Gottardi and Gumbiner, 2004). In order to determine whether posttranslational modifications (PTMs) of β-catenin underlie these different protein species, we have used 2DE separation and immunoblotting with an antibody specific for β-catenin. High-resolution separation of differentially modified species of β-catenin in 2DE required the addition of ASB-16, a zwitterionic detergent that can solubilise integral membrane proteins. ASB-16 was also necessary for focussing of other armadillo repeat proteins, such as γ-catenin and p120-catenin. 2DE using ASB-16 allowed detection of a previously unreported phosphorylation site in the transcriptionally active form of β-catenin that binds to GST-Tcf in response to Wnt signalling.

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