Details

Autor(en) / Beteiligte

• Tripathi, Rachana
• Kota, Satya Keerthi
• Srinivas, Usha K

Titel

Cullin4B/E3-ubiquitin ligase negatively regulates beta-catenin

Ist Teil von

• Journal of biosciences, 2007-09, Vol.32 (6), p.1133-1138

Ort / Verlag

India

Erscheinungsjahr

2007

Quelle

MEDLINE

Beschreibungen/Notizen

• 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.