Behavioral genetics of caenorhabditis elegans unc-103-encoded erg-like K(+) channel.
The Caenorhabditis elegans unc-103 gene encodes a potassium channel whose sequence is most similar to the ether-a-go-go related gene (erg) type of K+ channels. We find that the n 500 and e 1597 gain-of-function (gf) mutations in unc-103 cause reduced excitation in most muscles, while loss-of-function (lf) mutations cause mild muscle hyper-excitability. Both gf alleles change the same residue near the cytoplasmic end of S6, consistent with this region regulating channel activation. We also report additional dominant-negative and lf alleles of unc-103 that can antagonize or reduce the function of both gf and wild-type alleles. The unc-103 locus contains 6 promoter regions that express unc-103 in different combinations of body-wall and sex-specific muscles, motor-, inter- and sensory-neurons. Each promoter drives transcripts containing a unique first exon, conferring sequence variability to the N-terminus of the UNC-103 protein, while three splice variants introduce variability into the UNC-103 C-terminus. unc-103(0) hermaphrodites prematurely lay embryos that would normally be retained in the uterus and lay eggs under conditions that inhibit egg-laying behavior. In the egg-laying circuit, unc-103 is expressed in vulval muscles and the HSN neurons from different promoters. Supplying the proper UNC-103 isoform to the vulval muscles is sufficient to restore regulation to egg-laying behavior.
Reiner
David J
DJ
Department of Genome Sciences, University of Washington, Seattle, WA, USA.
Weinshenker
David
D
Tian
Hong
H
Thomas
James H
JH
Nishiwaki
Kiyoji
K
Miwa
Johji
J
Gruninger
Todd
T
Leboeuf
Brigitte
B
Garcia
L Rene
LR
D000483:Alleles; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics*; D005091:Exons / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D017238:Genes, Helminth / Q000235:genetics; D008124:Locomotion / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D015221:Potassium Channels / Q000737:chemistry / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D012098:Reproduction / Q000502:physiology
D029742:Caenorhabditis elegans Proteins; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D020033:Protein Isoforms; C474006:UNC-103 protein, C elegans