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A Time-Efficient Fluorescence Spectroscopy-Based Assay for Evaluating Actin Polymerization Status in Rodent and Human Brain Tissues
Published on: June 3, 2021
The natural product cucurbitacin E inhibits depolymerization of actin filaments
Pia M Sörensen1, Roxana E Iacob, Marco Fritzsche
1Dana-Farber Cancer Institute and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
ACS Chemical Biology
|June 26, 2012
Summary
Cucurbitacin E, a plant-derived compound, inhibits actin depolymerization by covalently binding to filamentous actin (F-actin). This natural product offers a new research tool for studying cell dynamics.
Area of Science:
- Cell Biology
- Biochemistry
- Natural Products Chemistry
Background:
- Small molecule actin modulators are crucial research tools.
- Currently, only jasplakinolide is a commercially available cell-permeable inhibitor of actin depolymerization.
Purpose of the Study:
- To identify and characterize novel small molecule inhibitors of actin depolymerization.
- To investigate the mechanism of action of cucurbitacin E on actin dynamics.
Main Methods:
- In vitro actin polymerization and depolymerization assays using fluorescently labeled actin.
- Biochemical assays to determine binding kinetics and site on actin.
- Live-cell imaging using fluorescence loss after photoactivation.
- Compatibility studies with phalloidin staining.
Main Results:
- Cucurbitacin E inhibits actin depolymerization at substoichiometric concentrations.
- It specifically binds to filamentous actin (F-actin) via a covalent bond at Cys257.
- Cucurbitacin E binds to a different site than jasplakinolide and phalloidin.
- Inhibition of actin depolymerization by cucurbitacin E was confirmed in live cells.
Conclusions:
- Cucurbitacin E is a novel, plant-derived inhibitor of actin depolymerization with a unique mechanism of action.
- It represents a valuable new research tool for studying cellular actin dynamics and related processes like cytokinesis.
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