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Updated: Jun 10, 2026
10:27
Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta
Published on: December 5, 2019
Id1 enhances RING1b E3 ubiquitin ligase activity through the Mel-18/Bmi-1 polycomb group complex
1Department of Pathology, College of Medicine, Hanyang University, Seoul, Republic of Korea.
Oncogene
|August 11, 2010
Summary
The helix-loop-helix inhibitor of differentiation and DNA binding (Id1) oncogene regulates epigenetic gene silencing by Polycomb group (PcG) proteins. This Id1 activity promotes tumor development through PcG-mediated epigenetic regulation.
Area of Science:
- Molecular Biology
- Epigenetics
- Oncology
Background:
- The helix-loop-helix inhibitor of differentiation and DNA binding (Id1) is a known oncogene implicated in various tumors.
- Its role in epigenetic transcriptional regulation remains unclear.
Purpose of the Study:
- To investigate the effect of Id1 on Polycomb group (PcG) proteins, key epigenetic gene silencers.
- To elucidate the mechanisms by which Id1 influences epigenetic regulation and contributes to tumor development.
Main Methods:
- Examined Id1's effect on Mel-18 and Bmi-1 expression, components of Polycomb Repressive Complex 1.
- Utilized Akt pathway analysis and promoter-reporter assays.
- Assessed E3 ligase RING1b activity and H2A ubiquitination levels.
Main Results:
- Id1 downregulated Mel-18 expression via the Akt pathway, upregulating c-Myc.
- Id1 regulated Bmi-1 transcription through c-Myc binding to its promoter.
- Id1 overexpression enhanced RING1b E3 ligase activity, leading to geminin degradation.
Conclusions:
- Established a novel link between Id1 and PcG proteins in epigenetic regulation.
- Suggests Id1 contributes to tumor development through PcG-mediated epigenetic mechanisms.
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