title: SLO-2 potassium channel is an important regulator of neurotransmitter release in Caenorhabditis elegans.
abstract: Slo2 channels are prominent K(+) channels in mammalian neurons but their physiological functions are not well understood. Here we investigate physiological functions and regulation of the Caenorhabditis elegans homologue SLO-2 in motor neurons through electrophysiological analyses of wild-type and mutant worms. We find that SLO-2 is the primary K(+) channel conducting delayed outward current in cholinergic motor neurons, and one of two K(+) channels with this function in GABAergic motor neurons. Loss-of-function mutation of slo-2 increases the duration and charge transfer rate of spontaneous postsynaptic current bursts at the neuromuscular junction, which are physiological signals used by motor neurons to control muscle cells, without altering postsynaptic receptor sensitivity. SLO-2 activity in motor neurons depends on Ca(2+) entry through EGL-19, an L-type voltage-gated Ca(2+) channel (CaV1), but not on other proteins implicated in either Ca(2+) entry or intracellular Ca(2+) release. Thus, SLO-2 is functionally coupled with CaV1 and regulates neurotransmitter release.
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
authors.forename: Bojun
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
authors.forename: Zhao-Wen
authors.initials: ZW
authors.lastname: Wang
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism; D059330:GABAergic Neurons / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009046:Motor Neurons / Q000378:metabolism; D032342:Muscle Cells / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009469:Neuromuscular Junction / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D015220:Calcium Channels; C109164:Egl-19 protein, C elegans; D026901:Membrane Transport Proteins; D009124:Muscle Proteins; D018377:Neurotransmitter Agents; C402625:SLO-2 protein, C elegans