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Updated: Mar 26, 2026
08:42
Ex Vivo Imaging of Cell-specific Calcium Signaling at the Tripartite Synapse of the Mouse Diaphragm
Published on: October 4, 2018
8.4K
Calcium can mobilize and activate myosin-VI
Christopher Batters1, Dario Brack1, Heike Ellrich1
1Department of Cellular Physiology, Ludwig-Maximilians-Universität München, 80336 Munich, Germany; Center for Nanosciences München, 80799 Munich, Germany.
Summary
Calcium binding to myosin-VI motor protein regulates cellular processes like cell division and migration. This binding alters motor conformation, impacting its activity and cellular functions.
Area of Science:
- Cell Biology
- Biochemistry
- Biophysics
Background:
- Motor proteins are crucial for cellular motility, including endocytosis, cell division, and cancer cell migration.
- Myosin-VI is a key motor protein involved in these essential cellular processes.
Purpose of the Study:
- To investigate how calcium ions influence the conformation and activity of the myosin-VI motor protein.
- To elucidate the mechanism by which calcium-calmodulin binding affects myosin-VI structure and function.
Main Methods:
- Single particle analysis of electron microscopy data to resolve conformational changes.
- Fluorescence spectroscopy to identify interacting domains.
- Biochemical assays to quantify binding affinities.
Main Results:
- Calcium binding to calmodulin dramatically alters myosin-VI conformation and activity.
- Calcium-calmodulin binding increases affinity for myosin-VI by 2,500-fold.
- This interaction induces a major structural rearrangement, leading to a nonmotile, cargo-binding state.
Conclusions:
- Calcium-calmodulin acts as a switch, regulating myosin-VI motility and cellular functions.
- The mechanism involves a shift to a higher affinity binding site, exposing the IQ-motif and destabilizing the lever arm.
- This calcium-dependent regulation is vital for processes requiring precise motor protein timing and coordination.
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