GABAA receptor beta subunit heterogeneity: functional expression of cloned cDNAs

• Published in: The EMBO journal 1989-06, Vol.8 (6), p.1665-1670
• Main Authors: Ymer, S., Schofield, P. R., Draguhn, A., Werner, P., Köhler, M., Seeburg, P. H.
• Format: Article
• Language: English
• Subjects: Adrenal Medulla - metabolism; Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Brain - metabolism; Cattle; Cell receptors; Cell structures and functions; Cloning, Molecular; DNA - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Molecular and cellular biology; Molecular Sequence Data; Oocytes - metabolism; Protein Conformation; Rats; Receptors, GABA-A - genetics; Receptors, GABA-A - metabolism; Sequence Homology, Nucleic Acid; Xenopus
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1002/j.1460-2075.1989.tb03557.x

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.