GABA(A)-receptor assembly in vivo: lessons from subunit mutant mice.

The rules governing the assembly of GABA(A) receptors in vivo were assessed in subunit mutant mice. The transcription of individual subunit genes was regulated independently. The lack of a particular subunit did not result in a molecular rescue by an enhanced transcription of other subunits. In addition, the availability of an alpha- and beta-subunit was essential for receptor formation. Finally, highly selective recognition processes directed the subcellular targeting of receptors. The loss of a particular receptor subtype (alpha5) did not lead to a subcellular redistribution of the remaining subtype (alpha2) present in the same cell.