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Updated: Aug 4, 2026
15:28
Mutagenesis and Functional Analysis of Ion Channels Heterologously Expressed in Mammalian Cells
Published on: October 1, 2010
Mutants of a temperature-sensitive two-P domain potassium channel
M T Kunkel1, D B Johnstone, J H Thomas
1Departments of Anatomy, Washington University School of Medicine, Seattle, Washington, USA.
Summary
This study characterizes the TWK-18 potassium channel in C. elegans, finding its activity increases with temperature. Mutations in TWK-18 cause movement defects due to overactive channels.
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- The Caenorhabditis elegans genome contains at least 42 genes for TWK (two-P domain K(+)) channels.
- TWK channels are characterized by two pore regions and four transmembrane domains.
Purpose of the Study:
- To functionally characterize the TWK-18 potassium channel from C. elegans.
- To investigate the role of TWK-18 in movement and its temperature sensitivity.
Main Methods:
- Functional characterization of TWK-18 currents in Xenopus oocytes.
- Analysis of mutant alleles of the twk-18 gene.
- Promoter-green fluorescent protein fusion experiments to determine expression patterns.
Main Results:
- TWK-18 currents significantly increase with rising temperatures.
- Mutant twk-18 alleles lead to uncoordinated movement and paralysis in C. elegans.
- Mutant TWK-18 channels exhibit larger potassium currents compared to wild-type channels.
- TWK-18 is expressed in C. elegans body wall muscle.
Conclusions:
- Increased TWK-18 channel activity, particularly in body wall muscle, likely explains the movement defects observed in mutant animals.
- TWK-18 is a temperature-sensitive potassium channel involved in regulating movement in C. elegans.
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