GABA Signaling Flashcards
GABA stands for
Gamma Amino Butryric Acid
The amino group of GABA is in the ____ position
Gamma
The name of GABA is a misnomer because
it is not an acid
GABA functions as a ______
neurotransmitter
How is GABA produced
- in metabolic process of cell and then released
- manufactured in cytosol and in vesicles, this allows it to fuse with the membrane and be released
What all bind to GABA receptor
valium, barbiturates, Gabapentin, Anesthetics, and alcohol
GAD (Glutamic acid decarboxylase) catalyzes
removes carboxyl group from glutamate to form GABA
and CO2
GABA signalling activates neural _____
inhibition
Reactions of the ______ are responsible for the synthesis, conservation, and metabolism of GABA
GABA shunt
SSADH (succinic semialdehyde dehydrogenase) catalyzes
Succinic semialdehyde + NAD —-> NADH + Succinate
and reverse reaction
GABA-T catalyzes
Gamm-Amino Butryrate + Alpha-Ketoglutarate ——> Succinic semialdehyde + Glutamate (and reverse reaction)
(also note that B6 (biotin) is required as cofactor)
What is the cofactor for GABA-T
B6 (Biotin) ( this is the cofactor for all aminotransferases)
GABA receptors fall into a class of PLGC receptors what does that stand for
Pentameric ligand gated channels
How many total membrane -spanning regions does a GABA receptor have
20 (5 homologous subunits each of which has four membrane-spanning regions)
How many genes code for the GABA receptors subunits
19
The central core of the GABA receptor is a ____ channel
Choride ion channel
Benzodiazepine act on GABA receptors by
Bind between Alpha1 and Gamma2
extends how long the chloride channels is open
but they still require GABA to open the channel
Benzodiazepine binds to GABA receptors at
Alpha1 Gamma2 junction
GABA has 2 binding sites on a GABA receptor between
Alpha1 and Beta2 subunits
What terminus of GABA receptors is almost all extracellular
N-terminus
The C and N terminuses of GABA receptors are
extracellular
What terminus of GABA receptor binds most of GABA
N-terminus
What is the major Isoform of GABA receptor
alpha1,beta2,Gamma2
The alpha1,beta2,Gamma2 isoform of GABA receptors make up about ____% of all GABA receptors in the brain
80%
Etomidate binding sites for GABA receptor
are located in the transmembrane domain at beta/alpha interfaces
Phasic inhibition
is dependent on the release of neurotransmitter and occurs at the synapse
Tonic inhibition
is extrasynaptic, as the GABA is taken up at synapse some of it gets out of celft and acts on other neurons (they are acted on by this escaped GABA)
Glycine and GABA receptors are bound linked to other Glycine or GABA receptors respectively by what? This creates what factor
Gephyrin. This allows for the clustering of the receptors at synapses and dispersion of clusters during plasticity
GABA-T catalyzes
Gamm-Amino Butryrate + Alpha-Ketoglutarate ——> Succinic semialdehyde + Glutamate (and reverse reaction)
(also note that B6 (biotin) is required as cofactor)
What is the cofactor for GABA-T
B6 (Biotin) ( this is the cofactor for all aminotransferases)
GABA receptors fall into a class of PLGC receptors what does that stand for
Pentameric ligand gated channels
How many total membrane -spanning regions does a GABA receptor have
20 (5 homologous subunits each of which has four membrane-spanning regions)
How many genes code for the GABA receptors subunits
19
The central core of the GABA receptor is a ____ channel
Choride ion channel
Benzodiazepine act on GABA receptors by
Bind between Alpha1 and Gamma2
extends how long the chloride channels is open
but they still require GABA to open the channel
Benzodiazepine binds to GABA receptors at
Alpha1 Gamma2 junction
GABA has 2 binding sites on a GABA receptor between
Alpha1 and Beta2 subunits
What terminus of GABA receptors is almost all extracellular
N-terminus
The C and N terminuses of GABA receptors are
extracellular
What terminus of GABA receptor binds most of GABA
N-terminus
What is the major Isoform of GABA receptor
alpha1,beta2,Gamma2
The alpha1,beta2,Gamma2 isoform of GABA receptors make up about ____% of all GABA receptors in the brain
80%
Etomidate binding sites for GABA receptor
are located in the transmembrane domain at beta/alpha interfaces
Phasic inhibition
is dependent on the release of neurotransmitter and occurs at the synapse
Tonic inhibition
is extrasynaptic, as the GABA is taken up at synapse some of it gets out of celft and acts on other neurons (they are acted on by this escaped GABA)
Glycine and GABA receptors are bound linked to other Glycine or GABA receptors respectively by what? This creates what factor
Gephyrin. This allows for the clustering of the receptors at synapses and dispersion of clusters during plasticity
