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247 Glycosylation and composition of alpha7 neuronal nicotinic receptors expressed in vitro and in vivo
Author(s) -
Chen Dag,
Dang Hong,
Patrick Jim
Publication year - 1996
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(96)80436-9
Subject(s) - chen , glycosylation , citation , composition (language) , library science , in vivo , receptor , nicotinic agonist , neuroscience , psychology , biology , computer science , art , literature , genetics , paleontology
Most neuronal nicotinic acetylcholine receptors are pentameric hetero-oligomecs, Some neuronal nicotinic acetylcholine receptor subunits are able to form functional ligand-gated ion channels in transient expression systems, e. g. the alpha7 subunit expresses fully glycosylated protein in COS cells and Xenopus oocytes. Nlinked glycosylation at 2 out of the 3 potential sites are essential for alpha7 receptor function in oocytes. It is not clear however that these receptor subunits form homomeric receptors in viva. To address this problem, we purified receptors containing the alpha7 subunit using alpha bungarotoxin affinity columns and showed that it is glycosylated. To determine if any other known receptor subunits are co-purified we made specific antibodies against other receptor subunits expressed in the brain and used these antisera in quantitative western blots of the purified alpha7 receptors. In no case could we find any other immunoreactive component even under conditions in which we could have detected quantities corresponding to less than I R of the alpha7 protein present. We conclude that either the alpha7 receptor is indeed a home-oligomer m vrvo or that tt associates with an unidentified receptor subunit that does not cross react with any ofour most pan specific antrsera. Supported, In part. by grants horn NINDS INS 135461 and NINA (DAft-4077 I of NIH.