PT  - JOURNAL ARTICLE
AU  - Ariele P. Hanek
AU  - Henry A. Lester
AU  - Dennis A. Dougherty
TI  - Photochemical Proteolysis of an Unstructured Linker of the GABA<sub>A</sub>R Extracellular Domain Prevents GABA but Not Pentobarbital Activation
AID  - 10.1124/mol.109.059832
DP  - 2010 Jul 01
TA  - Molecular Pharmacology
PG  - 29--35
VI  - 78
IP  - 1
4099  - http://molpharm.aspetjournals.org/content/78/1/29.short
4100  - http://molpharm.aspetjournals.org/content/78/1/29.full
SO  - Mol Pharmacol2010 Jul 01; 78
AB  - The GABA type A receptor (GABAAR) is the major inhibitory receptor in the mammalian central nervous system and the target of numerous pharmaceuticals. The α-subunit of these pentameric Cys-loop neurotransmitter-gated ion channels contributes to the binding of both GABA and allosteric modulators such as the benzodiazepines, suggesting a role for this subunit in the conformational changes associated with activation of the receptor. Herein we use the nonsense suppression methodology to incorporate a photoactivatable unnatural amino acid and photochemically cleave the backbone of the α subunit of the α1β2 GABAAR in a linker region that is believed to span the subunit. Proteolytic cleavage impairs GABA but not pentobarbital activation, strongly suggesting that conformational changes involving this linker region are critical to the GABA activation pathway.Copyright © 2010 The American Society for Pharmacology and Experimental Therapeutics