A GABAA receptor of defined subunit composition and positioning: Concatenation of five subunits

We show that the five subunits of a γ-aminobutyric acid type A receptor (GABAA receptor) can be concatenated to yield a functional receptor. This concatenated receptor α1–β2–α1–γ2–β2 has the advantage of a known subunit arrangement. Most of its functional properties are not significantly different from a receptor formed by individual subunits. Extent of expression amounted to about 40% of that of non-concatenated receptors in Xenopus oocytes, after injection of oocytes with comparable amounts of cRNA coding for concatenated and non-concatenated receptors. The ability to express receptors consisting of five subunits enables detailed studies of GABAA receptor subtype selective compounds.