Two novel GABAA receptor subunits exist in distinct neuronal subpopulations.
Two cDNAs encoding novel GABAA receptor subunits were isolated from a rat brain library. These subunits, gamma 2 and delta, share approximately 35% sequence identity with alpha and beta subunits and form functional GABA-gated chloride channels when expressed alone in vitro. The gamma 2 subunit is the rat homolog of the human gamma 2 subunit recently shown to be important for benzodiazepine pharmacology. Cellular localization of the mRNAs encoding the gamma 2 and delta subunits in rat brain revealed that largely distinct neuronal subpopulations express the two subunits. The delta subunit distribution resembles that of the high affinity GABAA receptor labeled with [3H]muscimol; the gamma 2 subunit distribution resembles that of GABAA/benzodiazepine receptors labeled with [3H]flunitrazepam. These findings have implications for the composition of two different GABAA receptor subtypes and for information processing in networks using GABA for signaling.
Shivers
B D
BD
Center for Molecular Biology, Federal Republic of Germany.
Killisch
I
I
Sprengel
R
R
Sontheimer
H
H
Köhler
M
M
Schofield
P R
PR
Seeburg
P H
PH
D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011963:Receptors, GABA-A / Q000032:analysis* / Q000235:genetics
C546279:GABRG2 protein, human; C546281:Gabrg2 protein, rat; D012333:RNA, Messenger; D011963:Receptors, GABA-A; D004247:DNA