Antisense suppression of GABA(A) receptor beta subunit levels in cultured cerebellar granule neurons demonstrates their importance in receptor expression.
GABA(A) receptors in the CNS are pentameric molecules composed of alpha, beta, gamma, delta, epsilon and theta subunits. Studies on transfected cells have shown that GABA(A) receptor beta subunit isoforms can direct alpha1 subunit localization within the cell. To examine the role of selected subunits in governing GABA(A) receptor expression in neurons, cultures of rat cerebellar granule cells were grown with antisense or sense oligodeoxynucleotides (ODNs) specific for the alpha 1, beta 2 or gamma 2 subunits. These subunits are all expressed in granule neurons where they are thought to contribute to an abundant receptor type. Following ODN treatment, subunit expression and distribution were examined by western blotting, immunocytochemistry and RT-PCR. Treatment of the cultures with the antisense, but not the corresponding sense, ODNs reduced the levels of the targeted subunit polypeptides. In addition, the beta 2 antisense ODN reduced the level of the alpha1 subunit polypeptide without altering the level of its mRNA. In contrast, treatment with the beta 2 subunit antisense ODN did not alter gamma 2 subunit polypeptide expression, distribution or mRNA level. These findings suggest that the alpha1 subunit requires a beta subunit for assembly into GABA(A) receptors in cerebellar granule neurons.
Department of Pharmacology, Case Western Reserve University, School of Medicine, Cleveland 44106-4965, USA.
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M
Kumar
X
X
Luo
P L
PL
Quirk
R E
RE
Siegel
D000818:Animals; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D003594:Cytoplasmic Granules; D058787:GABA-A Receptor Antagonists; D015870:Gene Expression / Q000187:drug effects; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D021122:Protein Subunits; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000235:genetics / Q000378:metabolism
D058787:GABA-A Receptor Antagonists; D016376:Oligonucleotides, Antisense; D021122:Protein Subunits; D012333:RNA, Messenger; D011963:Receptors, GABA-A