GABAA receptor beta subunit heterogeneity: functional expression of cloned cDNAs.
Cloned cDNAs encoding two new beta subunits of the rat and bovine GABAA receptor have been isolated using a degenerate oligonucleotide probe based on a highly conserved peptide sequence in the second transmembrane domain of GABAA receptor subunits. The beta 2 and beta 3 subunits share approximately 72% sequence identity with the previously characterized beta 1 polypeptide. Northern analysis showed that both beta 2 and beta 3 mRNAs are more abundant in the brain than beta 1 mRNA. All three beta subunit encoding cDNAs were also identified in a library constructed from adrenal medulla RNA. Each beta subunit, when co-expressed in Xenopus oocytes with an alpha subunit, forms functional GABAA receptors. These results, together with the known alpha subunit heterogeneity, suggest that a variety of related but functionally distinct GABAA receptor subtypes are generated by different subunit combinations.
Ymer
S
S
Laboratory of Molecular Neuroendocrinology, University of Heidelberg, FRG.
Schofield
P R
PR
Draguhn
A
A
Werner
P
P
Köhler
M
M
Seeburg
P H
PH
D000313:Adrenal Medulla / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D002417:Cattle; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D011487:Protein Conformation; D051381:Rats; D011963:Receptors, GABA-A / Q000235:genetics* / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014981:Xenopus
D011963:Receptors, GABA-A; D004247:DNA