Related Experiment Video
Updated: May 23, 2026

In Vitro SUMOylation Assay to Study SUMO E3 Ligase Activity
Published on: January 29, 2018
SUMOylation of AhR modulates its activity and stability through inhibiting its ubiquitination
Xinrong Xing1, Hailian Bi, Alan K Chang
1School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China.
Abstract:
Aryl hydrocarbon receptor (AhR) is a transcription factor that belongs to the basic helix-loop-helix (bHLH) Per-Arnt-Sim homology domain (PAS) family. AhR can be activated by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (2, 3, 7, 8-TCDD) and once activated, it promotes the abnormal expression of cytochrome P450, leading to several diseases, including cancer. In this study, we showed that AhR is subjected to post-translational modification by SUMOylation and this modification could be reversed by SENP1. Two SUMOylation sites were identified, one in the bHLH domain (K63) and the other in the TAD domain (K510) of AhR. Substitution of either K63 or K510 with arginine resulted in reduced SUMOylation for AhR. Treatment of MCF-7 cells with TCDD led to a reduced level of SUMOylated AhR in a time-dependent manner, and this occurred mainly in the nucleus. SUMOylation of AhR enhanced its stability through inhibiting its ubiquitination. Moreover, SUMOylation also repressed the transactivation activity of AhR and this could be reversed by TCDD. These results suggested that SUMOylation of AhR might play an important role in the regulation of its function, and TCDD may activate the transcriptional activity of AhR through downregulating its SUMOylation.
Related Concept Videos
Covalently Linked Protein Regulators
These groups modify specific amino acids in a protein.
Regulation of Expression at Multiple Steps
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Regulation of Nuclear Protein Sorting
Histone Modification
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...

