Related Experiment Video
Updated: Aug 18, 2026

Reconstitution Of β-catenin Degradation In Xenopus Egg Extract
Published on: June 18, 2014
Analysis of beta-catenin aggregation and localization using GFP fusion proteins: nuclear import of alpha-catenin by
A L Giannini1, M M Vivanco, R M Kypta
1MRC Laboratory for Molecular Cell Biology, University College London, London, WC1E 6BT.
Abstract:
beta-Catenin plays essential roles in cell adhesion, by associating with cadherins, and as a signaling molecule, by interacting with the Tcf/LEF-1 family of transcription factors. In order to study the protein-protein interactions of beta-catenin in living cells, we fused it to green fluorescent protein (GFP). GFP-beta-catenin was incorporated into cell junctions but also accumulated in the nucleus, where it formed rod-like structures. The carboxyl-terminal armadillo repeats of GFP-beta-catenin were sufficient for nuclear localization, but formation of rods required the armadillo repeats and sequences in both the amino- and the carboxyl-terminal domains. Rod formation was prevented by coexpression of N-cadherin, APC, and Tcf-4, which bind to the armadillo repeats of beta-catenin, but not by coexpression of alpha-catenin, although alpha-catenin expression did prevent accumulation of beta-catenin in the nucleus. Interestingly, when alpha-catenin, beta-catenin, and Tcf-4 were coexpressed they colocalized in the nucleus, and this correlated with a decrease in beta-catenin/Tcf-dependent transcriptional activity. These results indicate that binding of beta-catenin to Tcf-4 overrides the function of alpha-catenin to sequester beta-catenin in the cytoplasm and suggest that alpha-catenin can regulate beta-catenin signaling in the nucleus.
More Related Videos
Related Concept Videos
Nuclear Protein Sorting
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Nuclear Localization Signals and Import
Reporter Genes
Commonly used reporter...
TGF - β Signaling Pathway
Catenins
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...

