Expression of Caenorhabditis elegans neurotransmitter receptors and ion channels in Xenopus oocytes.
Injection of Caenorhabditis elegans polyA RNA into Xenopus laevis oocytes led to the expression of neurotransmitter receptors that generated some unique responses, including ionotropic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors as well as receptors that coupled to G proteins, such as those to octopamine, norepinephrine, and angiotensin, which activated the oocyte's own phosphatidylinositol system and calcium-gated chloride channels. The oocytes also expressed chloride-conducting glutamate receptors, muscarinic acetylcholine receptors, and voltage-operated calcium channels. Unexpectedly, serotonin (5-hydroxytryptamine), dopamine, GABA, and kainate did not generate ionic currents, suggesting that the corresponding receptors were not expressed or were not functional in the oocytes. The use of X. laevis oocytes for expressing worm RNA demonstrates that there are many molecular components whose role remains to be clarified in the nematode. Among them are the nature of the endogenous agonists for the octopamine and angiotensin receptors and the subunits that compose the ionotropic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and the norepinephrine receptors that couple to the phosphoinositide cascade.
Instituto de Neurobiología, Universidad Nacional Autónoma de México-Campus Juriquilla, Querétaro AP1-1141, México. ataulfo@inb.unam.mx
Ataúlfo
A
Martínez-Torres
Ricardo
R
Miledi
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D004594:Electrophysiology; D005786:Gene Expression Regulation; D018698:Glutamic Acid / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D017470:Receptors, Glutamate / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000235:genetics
D007473:Ion Channels; D043562:Receptors, G-Protein-Coupled; D017470:Receptors, Glutamate; D018698:Glutamic Acid