TY - JOUR
T1 - Immunochemical Characterization of the β2 Subunit of the GABAA Receptor
AU - Machu, Tina K.
AU - Olsen, Richard W.
AU - Browning, Michael D.
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1993/12
Y1 - 1993/12
N2 - To date three β subunits of the GABAA receptor have been identified in rat brain as a result of cDNA library screening. The β2 subunit has been reported to have a wide distribution in rat brain based on in situ hybridization studies quantifying β2 mRNA. To study the β2 subunit more directly, we have raised a polyclonal antibody to a synthetic peptide representing residues 315–334 of the intracellular loop of the β2 subunit. The antibody, which had been affinity‐purified, recognized the β2 peptide but did not immunolabel homologous β1 and β3 subunit peptides, indicating that this antibody is specific for the β2 subunit of the receptor. In western blots of the purified receptor, the antibody recognized a major diffuse band of 54–58 kDa arid exhibited minor labeling of lower‐molecular‐mass polypeptides. In western blots of cortex homogenate, the antibody exhibited nervous system‐specific labeling of a 55‐kDa band that comigrated with the 55‐kDa band of the purified receptor. Quantitative immunolabeling of this 55‐kDa polypeptide permitted direct determination of the relative amounts of the β2 subunit in different brain regions. The brainstem contained the highest relative specific activity of the β2 subunit, followed by the inferior colliculus, olfactory lobe, and cerebellum. Lower levels of immunolabeling were seen in hypothalamus, hippocampus, thalamus, and cortex.
AB - To date three β subunits of the GABAA receptor have been identified in rat brain as a result of cDNA library screening. The β2 subunit has been reported to have a wide distribution in rat brain based on in situ hybridization studies quantifying β2 mRNA. To study the β2 subunit more directly, we have raised a polyclonal antibody to a synthetic peptide representing residues 315–334 of the intracellular loop of the β2 subunit. The antibody, which had been affinity‐purified, recognized the β2 peptide but did not immunolabel homologous β1 and β3 subunit peptides, indicating that this antibody is specific for the β2 subunit of the receptor. In western blots of the purified receptor, the antibody recognized a major diffuse band of 54–58 kDa arid exhibited minor labeling of lower‐molecular‐mass polypeptides. In western blots of cortex homogenate, the antibody exhibited nervous system‐specific labeling of a 55‐kDa band that comigrated with the 55‐kDa band of the purified receptor. Quantitative immunolabeling of this 55‐kDa polypeptide permitted direct determination of the relative amounts of the β2 subunit in different brain regions. The brainstem contained the highest relative specific activity of the β2 subunit, followed by the inferior colliculus, olfactory lobe, and cerebellum. Lower levels of immunolabeling were seen in hypothalamus, hippocampus, thalamus, and cortex.
KW - Brain.
KW - GABA receptor
KW - β2 subunit antibody
UR - http://www.scopus.com/inward/record.url?scp=0027332650&partnerID=8YFLogxK
U2 - 10.1111/j.1471-4159.1993.tb07439.x
DO - 10.1111/j.1471-4159.1993.tb07439.x
M3 - Article
C2 - 8245958
AN - SCOPUS:0027332650
SN - 0022-3042
VL - 61
SP - 2034
EP - 2040
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
IS - 6
ER -