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Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications
Published on: April 21, 2023
PIASy-dependent SUMOylation regulates DNA topoisomerase IIalpha activity
Hyunju Ryu1, Maiko Furuta, Donald Kirkpatrick
1Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA.
The Journal of Cell Biology
|November 17, 2010
Summary
Small ubiquitin-like modifier (SUMO) modification of DNA topoisomerase IIα (TopoIIα) by PIASy inhibits its activity. SUMOylation at Lys660 is critical for regulating TopoIIα function during mitosis.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- DNA topoisomerase IIα (TopoIIα) is crucial for resolving DNA tangles at centromeres during mitosis.
- The regulatory mechanisms governing TopoIIα activity remain largely unknown.
Purpose of the Study:
- To investigate the role of SUMOylation in regulating TopoIIα activity.
- To identify the specific site and mechanism of SUMOylation-dependent inhibition of TopoIIα.
Main Methods:
- Mass spectrometry to identify SUMOylation sites.
- Biochemical assays to assess TopoIIα decatenation activity.
- Site-directed mutagenesis to analyze the role of specific lysine residues.
Main Results:
- PIASy-mediated SUMO2/3 modification of TopoIIα inhibits its decatenation activity.
- TopoIIα is SUMOylated at Lysine 660 (Lys660) within the DNA gate domain.
- Loss of SUMOylation at Lys660 abolishes the inhibitory effect, confirming its critical role.
Conclusions:
- SUMOylation, specifically at Lys660, is a key regulatory mechanism for TopoIIα activity on mitotic chromosomes.
- PIASy-mediated SUMOylation of TopoIIα provides a novel mechanism for controlling centromeric DNA catenation during mitosis.
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