HPV16 E6 and E6AP differentially cooperate to stimulate or augment Wnt signaling
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel)
- Research Division, The Peter MacCallum Cancer Centre, East Melbourne (Australia)
The present study investigated the roles of E6 and E6AP in the Wnt pathway. We showed that E6 levels are markedly reduced in cells in which Wnt signaling is activated. Coexpression of wild-type or mutant E6AP (C820A) in Wnt-activated cells stabilized E6 and enhanced Wnt/β-catenin/TCF transcription. Expression of E6AP alone in nonstimulated cells elevated β-catenin level, promoted its nuclear accumulation, and activated β-catenin/TCF transcription. A knockdown of E6AP lowered β-catenin levels. Coexpression with E6 intensified the activities of E6AP. Further experiments proved that E6AP/E6 stabilize β-catenin by protecting it from proteasomal degradation. This function was dependent on the catalytic activity of E6AP, the kinase activity of GSK3β and the susceptibility of β-catenin to GSK3β phosphorylation. Thus, this study identified E6AP as a novel regulator of the Wnt signaling pathway, capable of cooperating with E6 in stimulating or augmenting Wnt/β-catenin signaling, thereby possibly contributing to HPV carcinogenesis. - Highlights: • The roles of E6 and E6AP in the Wnt pathway were investigated. • E6AP stabilizes E6 and enhances E6 activity in augmentation of Wnt signaling. • E6AP cooperates with E6 to stabilize β-catenin and stimulate Wnt/β-catenin signaling. • E6AP and E6 act through different mechanisms to augment or stimulate Wnt signaling.
- OSTI ID:
- 22435075
- Journal Information:
- Virology, Vol. 468-470; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0042-6822
- Country of Publication:
- United States
- Language:
- English
Similar Records
ERβ induces the differentiation of cultured osteoblasts by both Wnt/β-catenin signaling pathway and estrogen signaling pathways
Agkihpin, a novel SVAE may inhibit the migration and invasion of liver cancer cells associated with the inversion of EMT induced by Wnt/β-catenin signaling inhibition