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Published on: July 30, 2014
Sodium channel activity in leukemia cells is directly controlled by actin polymerization
Y A Negulyaev1, S Y Khaitlina, H Hinssen
1Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Avenue, St. Petersburg 194064, Russia.
The Journal of Biological Chemistry
|October 4, 2000
Summary
Submembranous actin dynamics regulate sodium channels in non-excitable cells. Actin polymerization inhibits channel activity, while disassembly activates it, revealing a direct control mechanism.
Area of Science:
- Cell Biology
- Biophysics
- Molecular Physiology
Background:
- The actin cytoskeleton influences sodium-selective channels in non-excitable cells.
- Molecular mechanisms of actin's effect on channel function require elucidation.
Purpose of the Study:
- To investigate the role of submembranous actin dynamics in controlling sodium channels.
- To define the molecular mechanisms of actin-cytoskeleton regulation of ion channel activity.
Main Methods:
- Utilized inside-out patch clamp electrophysiology on human myeloid leukemia K562 cells.
- Manipulated submembranous actin dynamics using cytochalasin D, gelsolin, and purified actin.
Main Results:
- Disassembly of actin filaments with cytochalasin D or gelsolin activated non-voltage-gated sodium channels (12 pS conductance).
- Actin polymerization, induced by intact actin and MgCl(2), abolished channel activity.
- Actin's inhibitory effect was dependent on its polymerizability and polymerization conditions.
Conclusions:
- Sodium channel activity is directly controlled by the dynamic assembly and disassembly of submembranous F-actin.
- Actin polymerization acts as an inhibitory mechanism for these sodium channels.
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