Differential regulation of TRPM channels governs electrolyte homeostasis in the C. elegans intestine.
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.
Teramoto
Takayuki
T
Northwestern University Medical School, Institute for Neuroscience, Department of Molecular Pharmacology and Biological Chemistry, Searle 5-551, Chicago, Illinois 60611, USA.
Lambie
Eric J
EJ
Iwasaki
Kouichi
K
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
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