Quantitative assessment of β1- and β2-adrenergic receptor homo- and heterodimerization by bioluminescence resonance energy transfer
Quantitative assessment of β1- and β2-adrenergic receptor homo- and heterodimerization by bioluminescence resonance energy transfer
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DOI：
10.1074/jbc.m205767200
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发表时间：
2002-11-22
影响因子：
4.8
通讯作者：
Bouvier, M
中科院分区：
文献类型：
--
作者：
Mercier, JF;Salahpour, A;Bouvier, M
定量生物发光共振能量转移 (BRET) 分析应用于 β(1) 和 β(2) 肾上腺素受体同二聚和异二聚化的研究。为了评估每个原聚体之间的相对亲和力，在 HEK-293T 细胞中进行了 BRET 饱和实验。 β(1)-和β(2)-肾上腺素能受体被发现具有相似的同向和异向相互作用倾向，这表明，在两种受体亚型的表达水平相当时，会形成相等比例的同二聚体和异二聚体。数据分析还表明，在能量供体和受体的等摩尔表达水平下，超过 80% 的受体分子以二聚体形式存在，并且受体二聚化的高发生率对受体密度不敏感，表达水平在 1.4 至 26.9 pmol 受体/mg 膜蛋白之间变化。总而言之，这些结果表明细胞中表达的大多数受体以组成型二聚体形式存在，并且至少在未分化的成纤维细胞中，密切相关的β（1）-和β（2）-肾上腺素能受体之间的同二聚体和异二聚体的比例由它们的相对表达水平决定。
Quantitative bioluminescence resonance energy transfer (BRET) analysis was applied to the study of beta(1)- and beta(2)-adrenergic receptor homo- and heterodimerization. To assess the relative affinity between each of the protomers, BRET saturation experiments were carried out in HEK-293T cells. beta(1)- and beta(2)-adrenergic receptors were found to have similar propensity to engage in homo- and heterotropic interactions suggesting that, at equivalent expression levels of the two receptor subtypes, an equal proportion of homo- and heterodimers would form. Analysis of the data also revealed that, at equimolar expression levels of energy donor and acceptor, more than 80% of the receptor molecules exist as dimers and that this high incidence of receptor dimerization is insensitive to receptor density for expression levels varying between 1.4 and 26.9 pmol of receptor/mg of membrane protein. Taken together, these results indicate that most of the receptors expressed in cells exist as constitutive dimers and that, at least in undifferentiated fibroblasts, the proportion of homo- and heterodimers between the closely related beta(1)- and beta(2)-adrenergic receptors is determined by their relative levels of expression.