Modulation of recombinant GABA receptor/channel subunits by domain-specific antibodies in Xenopus oocytes.
To study interaction of specific antibodies with the GABA receptor/channel, antisera were raised against the extracellular domains of the GABAA receptor/channel beta2 subunit, gamma2 subunit and the GABAC receptor/channel rho1 subunit. The specificity of the antibodies was characterized by immunocytochemistry and by Western blotting of transfected FDC-P1 cells expressing recombinant GABA receptor/channel subunits. The effects of the antibodies on whole-cell currents in Xenopus laevis oocytes expressing homomeric recombinant GABA receptor/channel beta2, gamma2, and rho1 were studied using two-microelectrode voltage clamp. In the absence of GABA, anti-alpha2, anti-gamma2, and anti-rho1 antisera elicited whole-cell currents in oocytes expressing beta2, gamma2, and rho1 subunits, respectively. The effect of antibody on channel activation was concentration-dependent. The whole-cell currents induced by anti-beta2 and anti-gamma2 were several-fold greater than those induced by application of 100 microm GABA. In Xenopus oocytes expressing recombinant rho1 subunits, GABA-induced whole-cell currents were inhibited by the anti-rho1 antibody. In contrast, the GABA-induced whole-cell currents were potentiated several-fold by anti-beta2 and anti-gamma2 antibodies in Xenopus oocytes expressing homomeric beta2 and gamma2 subunits. Our studies indicate that antibodies specific to the N-terminal domain of GABA receptor/channel subunits can modulate the neurotransmitter receptor function.
Ekema
G M
GM
Department of Physiology and Biophysics, Wright State University School of Medicine, Dayton, OH 45435, USA.
Zheng
W
W
Wang
L
L
Lu
L
L
D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D000918:Antibody Specificity / Q000276:immunology / Q000502:physiology; D002460:Cell Line / Q000378:metabolism; D004594:Electrophysiology / Q000379:methods; D051379:Mice; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D018408:Patch-Clamp Techniques / Q000379:methods; D017434:Protein Structure, Tertiary / Q000502:physiology; D021122:Protein Subunits; D018079:Receptors, GABA / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000378:metabolism*; D014162:Transfection; D014981:Xenopus / Q000378:metabolism
D000906:Antibodies; C087200:GABA-C receptor; D021122:Protein Subunits; D018079:Receptors, GABA; D011963:Receptors, GABA-A; D011993:Recombinant Fusion Proteins