Recombinant AMPA receptors with low Ca2+ permeability increase intracellular Ca2+ in HEK 293 cells.
Although AMPA receptor subunit configuration controls the Ca2+ permeability of the ion channel, not much is known about Ca2+ signals generated by different AMPA receptor subtypes. We examined the Ca2+ signaling properties of recombinant AMPA receptors using patch clamp to determine ionic permeability properties and Ca2+ imaging to examine changes in intra-cellular Ca2+ level ([Ca2+]i). Activation of recombinant AMPA receptors robustly increased [Ca2+]i even in cells expressing heteromeric receptors containing edited GluRB, which harbored receptors with very low average Ca2+ permeability in patch clamp studies. The results suggest that whereas the GluRB subunit controls Ca2+ permeability, Ca2+ signaling mediated by AMPA receptors correlates poorly with the presence of GluRB.
Utz
A L
AL
Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232-6600, USA.
Verdoorn
T A
TA
D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D004594:Electrophysiology; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D016257:Fura-2; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D018091:Receptors, AMPA / Q000819:agonists / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D018690:Excitatory Amino Acid Agonists; D018091:Receptors, AMPA; D011994:Recombinant Proteins; D002118:Calcium; D016257:Fura-2