Related Experiment Videos
RelA suppresses the Wnt/beta-catenin pathway without exerting trans-acting transcriptional ability
Osamu Masui1, Yoshihide Ueda, Akiko Tsumura
1Department of Viral Oncology, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
Abstract:
Several cellular signaling systems exhibit cross talk. Cross talk seems to play an important role in modifying signal effects. In vertebrates, the nuclear factor kappa B (NF-kappaB) signaling pathway plays important roles in immune response, inflammation and apoptosis. Meanwhile, the Wnt/beta-catenin signaling pathway is involved in oncogenesis and development. We show here that RelA, a component of NF-kappaB, specifically suppressed beta-catenin/Tcf-dependent transcription. This suppression did not depend on the trans-acting transcriptional ability of RelA. Furthermore, RelA neither affected the nuclear import of beta-catenin nor the DNA binding ability of the beta-catenin/Tcf complex, suggesting that NF-kappaB modifies this signaling pathway after the binding of the beta-catenin/Tcf complex with target DNA.
Insights
Nuclear factor kappa B (NF-kappaB) signaling suppresses Wnt/beta-catenin activity. RelA, an NF-kappaB component, inhibits beta-catenin/Tcf transcription without affecting nuclear import or DNA binding, indicating post-DNA binding interference.
Area of Science:
- Cellular biology
- Molecular signaling pathways
- Cancer research
Background:
- Cellular signaling pathways, including nuclear factor kappa B (NF-kappaB) and Wnt/beta-catenin, are crucial for various biological processes.
- Cross talk between these pathways can significantly alter cellular responses.
- NF-kappaB is involved in immune response, inflammation, and apoptosis, while Wnt/beta-catenin regulates development and oncogenesis.
Purpose of the Study:
- To investigate the interaction and cross talk between the NF-kappaB and Wnt/beta-catenin signaling pathways.
- To determine the specific mechanism by which NF-kappaB influences Wnt/beta-catenin transcriptional activity.
Main Methods:
- Utilized molecular biology techniques to study the effects of RelA (a component of NF-kappaB) on beta-catenin/Tcf-dependent transcription.
- Assessed the impact of RelA on beta-catenin nuclear import and the DNA binding ability of the beta-catenin/Tcf complex.
Main Results:
- RelA specifically suppressed beta-catenin/Tcf-dependent transcription.
- This suppression was independent of RelA's transcriptional activity.
- RelA did not interfere with the nuclear import of beta-catenin or the DNA binding of the beta-catenin/Tcf complex.
Conclusions:
- NF-kappaB signaling, via RelA, negatively regulates Wnt/beta-catenin transcriptional activity.
- The suppression occurs at a post-DNA binding stage, suggesting a novel cross talk mechanism.
- This finding has implications for understanding cellular signaling in development and diseases like cancer.