title: Differential regulation of TRPM channels governs electrolyte homeostasis in the C. elegans intestine.
abstract: The transient receptor potential (TRP) channels are implicated in various cellular processes, including sensory signal transduction and electrolyte homeostasis. We show here that the GTL-1 and GON-2 TRPM channels regulate electrolyte homeostasis in the C. elegans intestine. GON-2 is responsible for a large outwardly rectifying current of intestinal cells, and its activity is tightly regulated by intracellular Mg(2+) levels, while GTL-1 mainly contributes to appropriate Mg(2+) responsiveness of the outwardly rectifying current. We also used nickel cytotoxicity to study the function of these channels. Both GON-2 and GTL-1 are necessary for intestinal uptake of nickel, but GTL-1 is continuously active while GON-2 is inactivated at higher Mg(2+) levels. This type of differential regulation of intestinal electrolyte absorption ensures a constant supply of electrolytes through GTL-1, while occasional bursts of GON-2 activity allow rapid return to normal electrolyte concentrations following physiological perturbations.
authors.affiliation: Northwestern University Medical School, Institute for Neuroscience, Department of Molecular Pharmacology and Biological Chemistry, Searle 5-551, Chicago, Illinois 60611, USA.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Teramoto
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Lambie
authors.forename: Kouichi
authors.initials: K
authors.lastname: Iwasaki
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D004573:Electrolytes / Q000378:metabolism*; D006706:Homeostasis; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000166:cytology; D007473:Ion Channels / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008274:Magnesium / Q000378:metabolism; D009154:Mutation; D009532:Nickel / Q000633:toxicity; D010802:Phylogeny; D015398:Signal Transduction / Q000502:physiology
chemical_list: D029742:Caenorhabditis elegans Proteins; D004573:Electrolytes; C487576:GON-2 protein, C elegans; C504382:GTL-1 protein, C elegans; D007473:Ion Channels; D009532:Nickel; D008274:Magnesium; D002118:Calcium