Inefficient cell-surface expression of hybrid complexes formed by the co-assembly of neuronal nicotinic acetylcholine receptor and serotonin receptor subunits
Inefficient cell-surface expression of hybrid complexes formed by the co-assembly of neuronal nicotinic acetylcholine receptor and serotonin receptor subunits
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DOI：
10.1016/s0028-3908(01)00042-9
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发表时间：
2001-07-01
影响因子：
4.7
通讯作者：
Millar, NS
中科院分区：
文献类型：
--
作者：
Harkness, PC;Millar, NS
先前的研究表明，在转染的哺乳动物细胞系的细胞表面表达相对较低的α 4 β 2神经元尼古丁乙酰胆碱受体（nAChRs），但这些亚基与含有神经元nAChR α 4或β 2亚基的n端部分的嵌合亚基以及5-HT3A亚基的c端结构域的嵌合亚基共表达可显著上调表面表达水平。最近的研究还表明，nAChR α 4亚基可以与5-羟色胺受体5-HT3A亚基以“混杂”的方式共同组装，形成功能性杂交受体。在本研究中，我们检验了α 4或β 2与5-HT3A本身（而不是与α 4/5-HT3A或β 2/5-HT3A亚基嵌合体）共组装是否也能促进α 4和β 2亚基在转染的哺乳动物细胞中的细胞表面表达。通过免疫沉淀、细胞表面抗体结合和放射性配体结合获得证据，表明5-HT3A可以与α 4和β 2 nAChR亚基共组装。然而，我们得出结论，5-HT3A与α 4或β 2的共组装并不能导致nAChR亚基在细胞表面的有效表达，并且共组装的杂交（nAChR亚基+ 5-HT3R亚基）受体复合物在细胞内大部分被保留。2001爱思唯尔科学有限公司版权所有。
Previous studies have demonstrated that relatively low levels of alpha4 beta2 neuronal nicotinic acetylcholine receptors (nAChRs) are expressed on the cell surface of transfected mammalian cell lines but that surface expression levels can be dramatically up-regulated by co-expression of these subunits with chimeric subunits containing the N-terminal portion of the neuronal nAChR alpha4 or beta2 subunits together with the C-terminal domain of the 5-HT3A subunit. Recent work has also suggested that the nAChR alpha4 subunit can co-assemble in a 'promiscuous' manner with the serotonin receptor 5-HT3A subunit to form functional hybrid receptors. In this study we have examined whether co-assembly of either alpha4 or beta2 with 5-HT3A itself (rather than with the alpha4/5-HT3A or beta2/5-HT3A subunit chimeras) can also facilitate cell surface expression of alpha4 and beta2 subunits in transfected mammalian cells. Evidence has been obtained by immunoprecipitation, cell-surface antibody binding and radioligand binding which indicates that the 5-HT3A can co-assemble with both the alpha4 and beta2 nAChR subunits. We conclude, however, that co-assembly of 5-HT3A with either alpha4 or beta2 does not result in efficient cell surface expression of the nAChR subunits and that co-assembled hybrid (nAChR subunit + 5-HT3R subunit) receptor complexes are largely retained within the cell. (C) 2001 Elsevier Science Ltd. All rights reserved.