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Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development
Published on: June 15, 2017
Domain movement in gelsolin: a calcium-activated switch
R C Robinson1, M Mejillano, V P Le
1Structural Biology Laboratory, Salk Institute for Biological Studies, Post Office Box 85800, San Diego, CA 92186-5800, USA.
Science (New York, N.Y.)
|December 3, 1999
Summary
The actin-binding protein gelsolin
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Gelsolin is an actin-binding protein crucial for regulating the actin cytoskeleton.
- It plays key roles in cellular processes like signaling, apoptosis, and movement.
- Gelsolin's function involves severing and capping actin filaments, a process regulated by calcium ions.
Purpose of the Study:
- To elucidate the structural basis of calcium-mediated gelsolin activation.
- To understand how gelsolin remodels the actin cytoskeleton at a molecular level.
Main Methods:
- X-ray crystallography was used to determine the 3.4 angstrom structure of the carboxyl-terminal half of gelsolin (domains G4-G6) bound to actin.
- Structural analysis focused on the conformational changes induced by calcium binding.
Main Results:
- Calcium binding triggers a significant conformational rearrangement in gelsolin.
- Domain G6 undergoes a large flip and translation relative to domains G4 and G5.
- This reorganization disrupts the beta sheet core of G4 and G6, exposing the actin-binding site.
Conclusions:
- The revealed structure explains the mechanism of gelsolin activation by calcium.
- The conformational changes directly enable gelsolin's actin-severing and capping activities.
- Understanding gelsolin's structural dynamics provides insights into actin cytoskeleton regulation.
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