Premium
Membrane Topology of the GluR1 Glutamate Receptor Subunit: Epitope Mapping by Site‐Directed Antipeptide Antibodies
Author(s) -
Molnár Elek,
McIlhinney R. A. Jeffrey,
Baude Agnès,
Nusser Zoltán,
Somogyi Péter
Publication year - 1994
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1994.63020683.x
Subject(s) - epitope , protein subunit , glutamate receptor , antibody , receptor , biology , epitope mapping , chemistry , microbiology and biotechnology , biochemistry , immunology , gene
In order to define the membrane topology of the GluR1 glutamate receptor subunit, we have examined the location of epitopes. Antibodies were produced against peptides corresponding to putative extracellular and intracellular segments of the rat brain GluR1 glutamate receptor subunit. Immunocytochemistry at the electron microscopic level in the dentate gyrus of the hippocampal formation showed that epitopes for the antiserum to the N‐terminal part of the subunit are located at the extracellular face of the plasma membrane, whereas the antigenic determinants for the antiserum to the C‐terminal part are found at the intracellular face of the postsynaptic membrane. Furthermore, antibodies to the N‐terminal residues 253–267 reacted similarly with both intact and permeabilized synaptosomes, whereas the binding of antibodies to the C‐terminal residues 877–889 increased about 1.6‐fold following permeabilization. Our data suggest that the N‐ and C‐terminal regions are located on the opposite side of the membrane and, therefore, the GluR1 subunit probably has an odd number of membrane spanning segments. The antibody cross‐reactivities in different species and their effect on ligand binding activity were also established.