Structural elements of the γ-aminobutyric acid type A receptor conferring subtype selectivity for benzodiazepine site ligands

被引:42
作者
Renard, S
Olivier, A
Granger, P
Avenet, P
Graham, D
Sevrin, M
George, P
Besnard, F
机构
[1] Synthelabo, Dept Genom Biol, F-92500 Rueil Malmaison, France
[2] CNS Res Dept, F-92225 Bagneux, France
关键词
D O I
10.1074/jbc.274.19.13370
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
gamma-aminobutyric acid type A (GABA(A)) receptors comprise a subfamily of ligand-gated ion channels whose activity can be modulated by ligands acting at the benzodiazepine binding site on the receptor. The benzodiazepine binding site was characterized using a site-directed mutagenesis strategy in which amino acids of the alpha(5) subunit were substituted by their corresponding alpha(1) residues. Given the high affinity and selectivity of alpha(1)-containing compared with alpha(5)-containing GABA(A) receptors for zolpidem, mutated alpha(5) subunits were co-expressed with beta(2) and gamma(2) subunits, and the affinity of recombinant receptors for zolpidem was measured. One alpha(5) mutant (bearing P162T, E200G, and T204S) exhibited properties similar to that of the alpha(1) subunit, notably high affinity zolpidem binding and potentiation by zolpidem of GABA-induced chloride current. Two of these mutations, alpha(5)P162T and alpha(5)E200G, might alter binding pocket conformation, whereas alpha(5)T204S probably permits formation of a hydrogen bond with a proton acceptor in zolpidem, These three amino acid substitutions also influenced receptor affinity for CL218872, Our data thus suggest that corresponding amino acids of the alpha(1) subunit, particularly alpha(1)-Ser(204), are the crucial residues influencing ligand selectivity at the binding pocket of alpha(1)-containing receptors, and a model of this binding pocket is presented.
引用
收藏
页码:13370 / 13374
页数:5
相关论文
共 26 条
[1]   Two tyrosine residues on the alpha subunit are crucial for benzodiazepine binding and allosteric modulation of gamma-aminobutyric acid(A) receptors [J].
Amin, J ;
BrooksKayal, A ;
Weiss, DS .
MOLECULAR PHARMACOLOGY, 1997, 51 (05) :833-841
[2]   Development of stable cell lines expressing different subtypes of GABA(A) receptors [J].
Besnard, F ;
Even, Y ;
Itier, V ;
Granger, P ;
Partiseti, M ;
Avenet, P ;
Depoortere, H ;
Graham, D .
JOURNAL OF RECEPTOR AND SIGNAL TRANSDUCTION RESEARCH, 1997, 17 (1-3) :99-113
[3]   A point mutation in the gamma(2) subunit of gamma-aminobutyric acid type A receptors results in altered benzodiazepine binding site specificity [J].
Buhr, A ;
Sigel, E .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1997, 94 (16) :8824-8829
[4]   Subtle changes in residue 77 of the gamma subunit of alpha 1 beta 2 gamma 2 GABA(A) receptors drastically alter the affinity for ligands of the benzodiazepine binding site [J].
Buhr, A ;
Baur, R ;
Sigel, E .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1997, 272 (18) :11799-11804
[5]  
Buhr A, 1996, MOL PHARMACOL, V49, P1080
[6]   HIGH-EFFICIENCY TRANSFORMATION OF MAMMALIAN-CELLS BY PLASMID DNA [J].
CHEN, C ;
OKAYAMA, H .
MOLECULAR AND CELLULAR BIOLOGY, 1987, 7 (08) :2745-2752
[7]  
CHENG Y, 1973, BIOCHEM PHARMACOL, V22, P3099
[8]   SITE-DIRECTED MUTAGENESIS OF VIRTUALLY ANY PLASMID BY ELIMINATING A UNIQUE SITE [J].
DENG, WP ;
NICKOLOFF, JA .
ANALYTICAL BIOCHEMISTRY, 1992, 200 (01) :81-88
[9]  
DUCIC I, 1995, J PHARMACOL EXP THER, V272, P438
[10]   The major site of photoaffinity labeling of the gamma-aminobutyric acid type a receptor by [H-3]flunitrazepam is histidine 102 of the alpha subunit [J].
Duncalfe, LL ;
Carpenter, MR ;
Smillie, LB ;
Martin, IL ;
Dunn, SMJ .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (16) :9209-9214