Neuronal Nicotinic Acetylcholine Receptors in Drosophila: Antibodies Against an α-Like and a Non-α-Subunit Recognize the Same High-Affinity α-Bungarotoxin Binding Complex |
| |
Authors: | Patrick Schloss Heinrich Betz Christiane Schroder Eckart D Gundelfinger |
| |
Institution: | ZMBH, Universit?t Heidelberg, F.R.G. |
| |
Abstract: | ALS and ARD proteins are thought to represent a ligand binding and a structural subunit, respectively, of Drosophila nicotinic acetylcholine receptors (nAChRs). Here, antibodies raised against fusion constructs encompassing specific regions of the ALS and ARD proteins were used to investigate a potential association of these two polypeptides. Both ALS and ARD antisera removed 20-30% of the high-affinity binding sites for the nicotinic antagonist 125I-alpha-bungarotoxin (125I-alpha-Btx) from detergent extracts of fly head membranes. Combinations of both types of antisera also precipitated the same fraction of alpha-Btx binding sites, a result suggesting that both polypeptides are components of the previously defined class I 125I-alpha-Btx binding sites in the Drosophila CNS. 125I-alpha-Btx binding to a MS2 polymerase-ALS fusion protein containing the predicted antagonist binding region showed that the ALS protein indeed constitutes the ligand binding subunit of a nicotinic receptor complex. These data are consistent with neuronal nAChRs in Drosophila containing at least two types of subunits, ligand binding and structural ones. |
| |
Keywords: | Neuronal nicotinic acetylcholine receptors Immunoprecipitation α-Bungarotoxin Drosophila melanogaster |
|
|