Abstract
Purified preparations of the inhibitory glycine receptor (GlyR) contain α and β subunits, which share homologous primary structures and a common transmembrane topology with other members of the ligand-gated ion channel superfamily. Here, a β subunitspecific antiserum was shown to precipitate the [3H]strychnine binding sites localized on α subunits from membrane extracts of both rat spinal cord and mammalian cells co-transfected with α and β cDNAs. Further, inhibition of a homo-oligomeric GlyRs by picrotoxinin, a non-competitive blocker of ion flow, was reduced 50- to 200-fold for α/β hetero-oligomeric receptors generated by cotransfection. Site-directed mutagenesis identified residues within the second predicted transmembrane segment (M2) of the β subunit as major determinants of picrotoxinin resistance. These data implicate the M2 segment in blocker binding to and lining of the GlyR chloride channel.
Original language | English |
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Pages (from-to) | 4305-4311 |
Number of pages | 7 |
Journal | EMBO Journal |
Volume | 11 |
Issue number | 12 |
State | Published - 1992 |
Externally published | Yes |
Keywords
- Channel block
- Glycine receptor
- Heterologous expression
- Picrotoxinin
- Subunit assembly