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GABAC Receptors: A Molecular View

2001; De Gruyter; Volume: 382; Issue: 8 Linguagem: Inglês

10.1515/bc.2001.141

1437-4315

Ralf Enz,

Receptor Mechanisms and Signaling

In the central nervous system inhibitory neurotransmission is primarily achieved through activation of receptors for γaminobutyric acid (GABA). Three types of GABA receptors have been identified on the basis of their pharmacological and electrophysiological properties. The predominant type, termed GABAA, and a recently identified GABAC type, form ligandgated chloride channels, whereas GABAB receptors activate separate cation channels via G proteins. Based on their homology to nicotinic acetylcholine receptors, GABAC receptors are believed to be oligomeric protein complexes composed of five subunits in a pentameric arrangement. To date up to five different GABAC receptors subunits have been identified in various species. Recent studies have shed new light on the biological characteristics of GABAC receptors, including the chromosomal localization of its subunit genes and resulting links to deseases, the cloning of new splice variants, the identification of GABAC receptorassociated proteins, the identification of domains involved in subunit assembly, and finally structure/function studies examining functional consequences of introduced mutations. This review summarizes recent data in view of the molecular structure of GABAC receptors and presents new insights into the biological function of this protein in the retina.