A Mutation in the C. elegans EXP-2 Potassium Channel That Alters Feeding Behavior
M. Wayne Davis,
1*
Richard Fleischhauer,
2
Joseph A. Dent,
1
Rolf
H. Joho,
2
Leon Avery
1
The nematode pharynx has a potassium channel with unusual
properties, which allows the muscles to repolarize quickly and with the
proper delay. Here, the Caenorhabditis elegans exp-2 gene is
shown to encode this channel. EXP-2 is a Kv-type (voltage-activated) potassium channel that has inward-rectifying properties resembling those of the structurally dissimilar human
ether-à-go-go-related gene (HERG) channel. Null and
gain-of-function mutations affect pharyngeal muscle excitability in
ways that are consistent with the electrophysiological behavior of the
channel, and thereby demonstrate a direct link between the kinetics of
this unusual channel and behavior.
1 Department of Molecular Biology, University
of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA.
2 The Center for Basic Neuroscience, University of
Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA.
*
Present address: Department of Biology, University of Utah, Salt
Lake City, UT 84112-0840, USA.
To whom correspondence should be addressed. E-mail:
wdavis{at}biology.utah.edu
Present address: Department of Biology, McGill
University, Montreal, PQ H3A 1B1, Canada.
