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Updated: May 23, 2025
06:06
In Vitro Analysis of E3 Ubiquitin Ligase Function
Published on: May 14, 2021
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Activation dynamics of ubiquitin-specific protease 7
Gabrielle J Valles1, Emilie J Korchak1, Dane H Geddes-Buehre1
1Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06032.
Summary
Ubiquitin-specific protease 7 (USP7) enzyme activation can occur spontaneously. A variant linked to Hao-Fountain syndrome enhances USP7 dynamics and catalytic activity, revealing insights into enzyme function and disease.
Area of Science:
- Biochemistry
- Enzymology
- Structural Biology
Background:
- Ubiquitin-specific protease 7 (USP7) is vital for genome stability and immune responses.
- USP7 dysfunction is implicated in cancers and neurodevelopmental disorders like Hao-Fountain syndrome.
- USP7's catalytic residues adopt an inactive state, requiring substrate binding for activation.
Purpose of the Study:
- To investigate the conformational dynamics of USP7 in solution.
- To understand the role of these dynamics in enzyme activation.
- To explore the impact of disease-associated variants on USP7 dynamics and activity.
Main Methods:
- Combined CPMG NMR relaxation dispersion measurements.
- Enzyme kinetics analysis.
- Characterization of apo-USP7 and a disease-associated variant (G392D).
Main Results:
- Apo-USP7 exists in a dynamic equilibrium between inactive and low-population active conformations.
- Enzyme activation can occur spontaneously, independent of substrate binding.
- The G392D variant significantly enhances USP7's conformational dynamics and catalytic activity.
Conclusions:
- USP7 activation is intrinsically dynamic, involving transient exploration of active states.
- Changes in enzyme dynamics, particularly in disease variants, directly impact catalytic function.
- This study provides a mechanistic link between USP7 dynamics, enzyme activity, and disease pathogenesis.
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