Immunochemical identification of the alpha 1- and alpha 3-subunits of the GABAA-receptor in rat brain.
To identify subunit variants of the GABAA-receptor antisera were developed against specific cDNA-derived peptide sequences of the alpha 1- and alpha 3-subunits of rat brain. The alpha 1-subunit antiserum selectively recognized a protein of 50 +/- 1 kDa in rat and bovine GABAA-receptor preparations, while the alpha 3-subunit antiserum interacted with a protein doublet of 59 +/- 2 kDa and 61 +/- 3 kDa. The alpha 1-subunit immunoreactivity resides in a large population of GABAA-receptors as shown by immunoprecipitation of 63 +/- 6% of [3H]flumazenil binding sites with the alpha 1-subunit antiserum. In contrast, only 24 +/- 3% of receptor binding sites were precipitated with the alpha 3-subunit antiserum. Co-precipitation studies suggest that the alpha 1- and alpha 3-subunit immunoreactivities do not share the same receptor population while the gamma 2-subunit immunoreactivity is associated with the alpha 1-subunit immunoreactivity.
Benke
D
D
Institute of Pharmacology, University of Zurich, Switzerland.
Cicin-Sain
A
A
Mertens
S
S
Mohler
H
H
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D051381:Rats; D011963:Receptors, GABA-A / Q000032:analysis*
D011963:Receptors, GABA-A