The unc-8 and sup-40 genes regulate ion channel function in Caenorhabditis elegans motorneurons.
Two Caenorhabditis elegans genes, unc-8 and sup-40, have been newly identified, by genetic criteria, as regulating ion channel function in motorneurons. Two dominant unc-8 alleles cause motorneuron swelling similar to that of other neuronal types in dominant mutants of the deg-1 gene family, which is homologous to a mammalian gene family encoding amiloride-sensitive sodium channel subunits. As for previously identified deg-1 family members, unc-8 dominant mutations are recessively suppressed by mutations in the mec-6 gene, which probably encodes a second type of channel component. An unusual dominant mutation, sup-41 (lb125), also co-suppresses unc-8 and deg-1, suggesting the existence of yet another common component of ion channels containing unc-8 or deg-1 subunits. Dominant, transacting, intragenic suppressor mutations have been isolated for both unc-8 and deg-1, consistent with the idea that, like their mammalian homologues, the two gene products function as multimers. The sup-40 (lb130) mutation dominantly suppresses unc-8 motorneuron swelling and produces a novel swelling phenotype in hypodermal nuclei. sup-40 may encode an ion channel component or regulator that can correct the osmotic defect caused by abnormal unc-8 channels.
Shreffler
W
W
Department of Biochemistry, New York University Medical School, New York 10016, USA.
Magardino
T
T
Shekdar
K
K
Wolinsky
E
E
D000483:Alleles; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism; D005260:Female; D017238:Genes, Helminth; D016153:Genes, Suppressor; D005838:Genotype; D007473:Ion Channels / Q000235:genetics / Q000502:physiology*; D008297:Male; D009637:Masoprocol / Q000494:pharmacology; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000502:physiology*; D009154:Mutation; D009865:Oocytes; D010641:Phenotype; D013489:Suppression, Genetic / Q000235:genetics; D014882:Water-Electrolyte Balance
D007473:Ion Channels; D009637:Masoprocol