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Updated: Jul 10, 2026

Reconstitution Of β-catenin Degradation In Xenopus Egg Extract
Published on: June 17, 2014
Cullin4B/E3-ubiquitin ligase negatively regulates beta-catenin
Rachana Tripathi1, Satya Keerthi Kota, Usha K Srinivas
1Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
Abstract:
Beta-catenin is the key transducer of Wingless-type MMTV integration site family member (Wnt) signalling, upregulation of which is the cause of cancer of the colon and other tissues. In the absence of Wnt signals, beta-catenin is targeted to ubiquitin-proteasome-mediated degradation. Here we present the functional characterization of E3-ubiquitin ligase encoded by cul4B. RNAi-mediated knock-down of Cul4B in a mouse cell line C3H T10 (1/2) results in an increase in beta-catenin levels. Loss-of-function mutation in Drosophila cul4 also shows increased beta-catenin/Armadillo levels in developing embryos and displays a characteristic naked-cuticle phenotype. Immunoprecipitation experiments suggest that Cul4B and beta-catenin are part of a signal complex in Drosophila, mouse and human. These preliminary results suggest a conserved role for Cul4B in the regulation of beta-catenin levels.
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