Effects of hyperkinetic, a beta subunit of Shaker voltage-dependent K+ channels, on the oxidation state of presynaptic nerve terminals

Atsushi Ueda; Chun-Fang Wu

doi:10.1080/01677060701807954

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Effects of hyperkinetic, a beta subunit of Shaker voltage-dependent K+ channels, on the oxidation state of presynaptic nerve terminals

Journal article

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Effects of hyperkinetic, a beta subunit of Shaker voltage-dependent K+ channels, on the oxidation state of presynaptic nerve terminals

Atsushi Ueda and Chun-Fang Wu

Journal of neurogenetics, Vol.22(2), pp.1-115

2008

DOI: 10.1080/01677060701807954

PMCID: PMC2716212

PMID: 18428031

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https://www.ncbi.nlm.nih.gov/pmc/articles/2716212View

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Abstract

The Drosophila Hyperkinetic (Hk) gene encodes a beta subunit of Shaker (Sh) K+ channels and shows high sequence homology to aldoketoreductase. Hk mutations are known to modify the voltage dependence and kinetics of Sh currents, which are also influenced by the oxidative state of the N-terminus region of the Sh channel, as demonstrated in heterologous expression experiments in frog oocytes. However, an in vivo role of Hk in cellular reduction/oxidation (redox) has not been demonstrated. By using a fluorescent indicator of reactive oxygen species (ROS), dihydrorhodamine-123 (DHR), we show that the presynaptic nerve terminal of larval motor axons is metabolically active, with more rapid accumulation of ROS in comparison with muscle cells. In Hk terminals, DHR fluorescence was greatly enhanced, indicating increased ROS levels. This observation implicates a role of the Hk beta subunit in redox regulation in presynaptic terminals. This phenomenon was paralleled by the expected effects of the mutations affecting glutathione S-transferase S1 as well as applying H2O2 to wild-type synaptic terminals. Thus, our results also establish DHR as a useful tool for detecting ROS levels in the Drosophila neuromuscular junction.

Reactive Oxygen Species - metabolism

Oxidation-Reduction

Presynaptic Terminals - drug effects

Neuromuscular Junction - metabolism

Hydrogen Peroxide - pharmacology

Potassium Channels - physiology

Drosophila melanogaster - metabolism

Drosophila Proteins - physiology

Animals

Glutathione Transferase - genetics

Glutathione Transferase - physiology

Rhodamines

Presynaptic Terminals - metabolism

Mutation

Details

Title: Subtitle: Effects of hyperkinetic, a beta subunit of Shaker voltage-dependent K+ channels, on the oxidation state of presynaptic nerve terminals
Creators: Atsushi Ueda - Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242, USA
Chun-Fang Wu
Resource Type: Journal article
Publication Details: Journal of neurogenetics, Vol.22(2), pp.1-115
DOI: 10.1080/01677060701807954
PMID: 18428031
PMCID: PMC2716212
NLM abbreviation: J Neurogenet
ISSN: 0167-7063
eISSN: 1563-5260
Publisher: England
Grant note: R01 NS026528 / NINDS NIH HHS HD18577 / NICHD NIH HHS R01 NS026528-17 / NINDS NIH HHS P01 HD018577-220003 / NICHD NIH HHS NS26528 / NINDS NIH HHS P01 HD018577-210003 / NICHD NIH HHS R01 NS026528-16 / NINDS NIH HHS P01 HD018577 / NICHD NIH HHS
Language: English
Date published: 2008
Academic Unit: Iowa Neuroscience Institute; Biology
Record Identifier: 9984070667102771

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