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Updated: Jul 12, 2026
09:45
In Vitro SUMOylation Assay to Study SUMO E3 Ligase Activity
Published on: January 29, 2018
TOPORS functions as a SUMO-1 E3 ligase for chromatin-modifying proteins
Pooja Pungaliya1, Diptee Kulkarni, Hye-Jin Park
1Department of Pharmacology, The Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 195 Little Albany Street, New Brunswick, New Jersey 08901, USA.
Journal of Proteome Research
|September 7, 2007
Summary
TOPORS protein, a dual ubiquitin and SUMO-1 ligase, acts as a tumor suppressor. It regulates proteins like mSin3A involved in chromatin modification, suggesting a role in preventing cancer progression.
Area of Science:
- Molecular Biology
- Oncology
- Proteomics
Background:
- TOPORS is a unique protein possessing both ubiquitin and SUMO-1 E3 ligase activities.
- It has been identified as a potential tumor suppressor across various cancers.
Purpose of the Study:
- To elucidate the cellular functions of TOPORS.
- To identify proteins regulated by TOPORS through sumoylation.
Main Methods:
- A proteomic screen was employed to discover TOPORS sumoylation substrates.
- Transfection studies were conducted to validate identified substrates.
Main Results:
- The screen identified numerous candidate substrates involved in chromatin modification and transcriptional regulation.
- Mammalian Sin3A (mSin3A) was confirmed as a sumoylation substrate of TOPORS.
Conclusions:
- TOPORS may exert its tumor suppressor function by regulating mSin3A and other chromatin-modifying proteins.
- These findings highlight TOPORS's role in epigenetic regulation and cancer suppression.
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