Transmembrane topology of the glutamate receptor subunit GluR6.

摘要: Ionotropic glutamate receptors mediate most rapid excitatory synaptic transmission in the mammalian central nervous system. These are divided into alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA), kainate, and N-methyl-D-aspartate based on pharmacological electrophysiological characteristics. receptor subunits integral membrane proteins that have been proposed to a large extracellular ligand-binding N-terminal domain, four hydrophobic transmembrane domains, an C-terminal domain. In this study we shown both AMPA (GluR1-4) kainate (GluR6/7) glycosylated adult rat brain; however, greater extent. Examination of sequences revealed several additional consensus sites for N-linked glycosylation; interestingly, one these is located major intracellular loop subunits. To test topology model receptors, used site-specific mutagenesis GluR6 subunit remove glycosylation site within loop. Mutagenesis demonstrates it transiently transfected human embryonic kidney cells, which express functional receptors. Since has only found occur domains plasma proteins, results suggest incorrect. Combining with other recent data, alternative model.