Expression of Functional Human α6β2β3*Acetylcholine Receptors in Xenopus laevis Oocytes Achieved through Subunit Chimeras and Concatamers
Expression of Functional Human α6β2β3*Acetylcholine Receptors in Xenopus laevis Oocytes Achieved through Subunit Chimeras and Concatamers
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DOI：
10.1124/mol.110.066159
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发表时间：
2011-01-01
影响因子：
3.6
通讯作者：
Lindstrom, Jon
中科院分区：
文献类型：
--
作者：
Kuryatov, Alexandre;Lindstrom, Jon
多巴胺能神经元上的α 6 β 2 β 3* 乙酰胆碱受体（AChR）是治疗尼古丁成瘾和帕金森病的药物的重要靶点。然而，在卵母细胞或转染细胞中有效表达功能性α 6 β 2 β 3* AChR是不可能的。α 6/α 3亚基嵌合体允许表达功能性AChR，并揭示α 6 M1跨膜结构域和大胞质结构域的部分损害装配。串联体亚基允许功能性α 6 β 2 β 3* AChR以限定的亚基组成和亚基顺序组装。辅助亚基的组装限制了成熟AChRs的形成。β 3辅助亚基和α 4或α 6亚基之间的单个接头足以允许组装复合β 3-（α 4 β 2）（α 6 β 2）或β 3-（α 6 β 2）（α 4 β 2）AChR。多聚五聚体如β 3-α 6-β 2-α 4-β 2已在功能上进行了表征。α 6 β 2 β 3* AChR对用于戒烟治疗的药物（尼古丁、伐尼克兰和金雀花碱）和沙泽替丁的激活敏感。所有这些都是部分激动剂。（α 6 β 2）（α 4 β 2）β 3乙酰胆碱受体对激动剂最敏感。（α 6 β 2）（2）β 3 AChR具有最大的Ca 2+渗透性。（α 4 β 2）（α 6 β 2）β 3乙酰胆碱受体最有效地转运到细胞表面，而（α 6 β 2）（2）β 3乙酰胆碱受体转运效率最低。多巴胺能神经元可能具有特殊的分子伴侣，用于组装辅助亚基与α 6亚基，并将（α 6 β 2）（2）β 3 AChR转运到细胞表面。联聚五聚体和由三聚体、二聚体和单体的组合形成的五聚体表现出相似的性质，表明亚基之间的接头不改变它们的功能性质。这些多联体首次允许分析α 6 β 2 β 3* AChR的功能特性。这些多联体应该能够选择特异性针对α 6 β 2 β 3* AChR的药物。
alpha 6 beta 2 beta 3* acetylcholine receptors (AChRs) on dopaminergic neurons are important targets for drugs to treat nicotine addiction and Parkinson's disease. However, it has not been possible to efficiently express functional alpha 6 beta 2 beta 3* AChRs in oocytes or transfected cells. alpha 6/alpha 3 subunit chimeras permit expression of functional AChRs and reveal that parts of the alpha 6 M1 transmembrane domain and large cytoplasmic domain impair assembly. Concatameric subunits permit assembly of functional alpha 6 beta 2 beta 3* AChRs with defined subunit compositions and subunit orders. Assembly of accessory subunits is limiting in formation of mature AChRs. A single linker between the beta 3 accessory subunit and an alpha 4 or alpha 6 subunit is sufficient to permit assembly of complex beta 3-(alpha 4 beta 2)(alpha 6 beta 2) or beta 3-(alpha 6 beta 2)(alpha 4 beta 2) AChRs. Concatameric pentamers such as beta 3-alpha 6-beta 2-alpha 4-beta 2 have been functionally characterized. alpha 6 beta 2 beta 3* AChRs are sensitive to activation by drugs used for smoking cessation therapy (nicotine, varenicline, and cytisine) and by sazetidine. All these are partial agonists. (alpha 6 beta 2)(alpha 4 beta 2)beta 3 AChRs are most sensitive to agonists. (alpha 6 beta 2)(2)beta 3 AChRs have the greatest Ca2+ permeability. (alpha 4 beta 2)(alpha 6 beta 2)beta 3 AChRs are most efficiently transported to the cell surface, whereas (alpha 6 beta 2)(2)beta 3 AChRs are the least efficiently transported. Dopaminergic neurons may have special chaperones for assembling accessory subunits with alpha 6 subunits and for transporting (alpha 6 beta 2)(2)beta 3 AChRs to the cell surface. Concatameric pentamers and pentamers formed from combinations of trimers, dimers, and monomers exhibit similar properties, indicating that the linkers between subunits do not alter their functional properties. For the first time, these concatamers allow analysis of functional properties of alpha 6 beta 2 beta 3* AChRs. These concatamers should enable selection of drugs specific for alpha 6 beta 2 beta 3* AChRs.