Charged residues in the alpha1 and beta2 pre-M1 regions involved in GABAA receptor activation.

ABSTRACT: For Cys-loop ligand-gated ion channels (LGIC), the protein movements that couple neurotransmitter binding to channel gating are not well known. The pre-M1 region, which links the extracellular agonist-binding domain to the channel-containing transmembrane domain, is in an ideal position to transduce binding site movements to gating movements. A cluster of cationic residues in this region is observed in all LGIC subunits, and in particular, an arginine residue is absolutely conserved. We mutated charged pre-M1 residues in the GABAA receptor alpha1 (K219, R220, K221) and beta2 (K213, K215, R216) subunits to cysteine and expressed the mutant subunits with wild-type beta2 or alpha1 in Xenopus oocytes. Cysteine substitution of beta2R216 abolished channel gating by GABA without altering the bind

SUBMITTER: Mercado J 

PROVIDER: S-EPMC6674915 | biostudies-literature | 2006 Feb

REPOSITORIES: biostudies-literature