Ligand-regulated oligomerization of beta(2)-adrenoceptors in a model lipid bilayer.
Ligand-regulated oligomerization of beta(2)-adrenoceptors in a model lipid bilayer.
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DOI：
10.1038/emboj.2009.267
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发表时间：
2009-11-04
期刊：
影响因子：
11.4
通讯作者：
Kobilka, Brian K.
中科院分区：
文献类型：
--
作者：
Fung, Juan Jose;Deupi, Xavier;Pardo, Leonardo;Yao, Xiao Jie;Velez-Ruiz, Gisselle A.;DeVree, Brian T.;Sunahara, Roger K.;Kobilka, Brian K.
β-2-肾上腺素能受体(β-2AR)是最早在细胞膜上形成寡聚体的A-G蛋白偶联受体(GPC)家族之一，但对寡聚体中前体的数量和排列、配体对寡聚体的组织和稳定性的影响以及对其他蛋白质促进寡聚化的要求还知之甚少。我们用荧光共振能量转移(FRET)表征了纯化的β-2AR在三个不同位置被荧光团特异性标记并重组为模型脂双层的齐聚反应。我们的结果表明，β-2AR在重组为磷脂小泡后主要是四聚体。激动剂和拮抗剂对齐聚物中原构体的相对取向影响不大。相反，反向激动剂的结合导致大多数标记对的FRET效率显著提高，这表明这类配体通过减少单个原激动剂的构象波动，促进了原激动剂的紧密堆积和/或更复杂的寡聚体的形成。这些结果为β2AR寡聚提供了新的结构见解，并提示了反向激动剂功能作用的可能机制。
The β2-adrenoceptor (β2AR) was one of the first Family A G protein-coupled receptors (GPCRs) shown to form oligomers in cellular membranes, yet we still know little about the number and arrangement of protomers in oligomers, the influence of ligands on the organization or stability of oligomers, or the requirement for other proteins to promote oligomerization. We used fluorescence resonance energy transfer (FRET) to characterize the oligomerization of purified β2AR site-specifically labelled at three different positions with fluorophores and reconstituted into a model lipid bilayer. Our results suggest that the β2AR is predominantly tetrameric following reconstitution into phospholipid vesicles. Agonists and antagonists have little effect on the relative orientation of protomers in oligomeric complexes. In contrast, binding of inverse agonists leads to significant increases in FRET efficiencies for most labelling pairs, suggesting that this class of ligand promotes tighter packing of protomers and/or the formation of more complex oligomers by reducing conformational fluctuations in individual protomers. The results provide new structural insights into β2AR oligomerization and suggest a possible mechanism for the functional effects of inverse agonists.
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影响因子：
7.3
作者：
Hill, SJ
通讯作者：
Hill, SJ
影响因子：
4.8
作者：
Ghanouni, P;Gryczynski, Z;Kobilka, BK
通讯作者：
Kobilka, BK
影响因子：
3.4
作者：
DOWNER, NW
通讯作者：
DOWNER, NW
影响因子：
11.4
作者：
Gether, U;Lin, S;Kobilka, BK
通讯作者：
Kobilka, BK
DOI：
10.1073/pnas.0701967104
发表时间：
2007-06-26
影响因子：
11.1
作者：
Ernst, Oliver P.;Gramse, Verena;Heck, Martin
通讯作者：
Heck, Martin