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Novel Nucleus-Oriented Quenched Activity-Based Probes Link Cathepsin Nuclear Localization with Mitosis
Karin Reut Shannon1, Tommy Weiss-Sadan1, Emmanuelle Merquiol1
1The Institute for Drug Research, The School of Pharmacy, The Faculty of Medicine, The Hebrew University, POB 12271, Jerusalem 9112001, Israel.
ACS Sensors
|February 17, 2025
Summary
New probes reveal nuclear cysteine cathepsin activity surges before cell division. These tools help understand protease roles in cell cycle progression and cancer development.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Cysteine cathepsins are proteases often upregulated in diseases like cancer.
- While typically endolysosomal, cathepsins also localize to the nucleus and influence the cell cycle.
- Investigating nuclear cathepsin function requires specific tools.
Purpose of the Study:
- To develop novel tools for studying nuclear cathepsin activity.
- To explore the role of cathepsins in cell cycle progression.
Main Methods:
- Design and synthesis of nucleus-directed quenched activity-based probes (qABPs) using cell-penetrating peptides (CPPs).
- Biochemical validation of CPP-qABPs for potency and selectivity.
- Application of qABPs in cell fractionation, multimodal flow cytometry-imaging, and time-lapse microscopy in living cells.
Main Results:
- CPP-qABPs demonstrated potent and selective activity.
- Confirmed nuclear cathepsin activity in living cells using various imaging techniques.
- Observed a distinct spatiotemporal pattern: a surge in nuclear cathepsin activity preceding mitosis.
Conclusions:
- Nuclear-directed qABPs are effective tools for real-time monitoring of nuclear cathepsin activity.
- The findings suggest previously unrecognized roles for cathepsins in cell division.
- These probes can advance research into protease involvement in cell division and cancer.
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