Computational analysis of the CB1 carboxyl-terminus in the receptor-G protein complex.
Computational analysis of the CB1 carboxyl-terminus in the receptor-G protein complex.
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受体-G 蛋白复合物中 CB1 羧基末端的计算分析。
DOI：
10.1002/prot.24999
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发表时间：
2016
期刊：
影响因子：
2.9
通讯作者：
Kendall,DebraA
中科院分区：
文献类型：
--
作者：
Shim,Joong-Youn;Khurana,Leepakshi;Kendall,DebraA
尽管活化的脑大麻素受体1 （CB1）的羧基端（Ct）在G蛋白信号传导的调节中发挥重要作用，但缺乏对其与G蛋白相互作用的结构理解。这在很大程度上是由于CB1 Ct的高度灵活性，它可以动态地适应G蛋白的存在。在本研究中，我们通过建立CB1 - Gi复合物的先前模型（Shim, Ahn, and Kendall, the Journal of Biological Chemistry 2013; 288:32449-32465）来探索CB1 Ct如何与G蛋白相互作用，以整合完整的CB1 Ct （Glu416Ct-Leu472Ct）。基于核磁共振研究的结构约束，我们使用ROSETTA来预测第三次褶皱，ZDOCK来预测对接方向，并通过分子动力学（MD）模拟来获得CB1‐Gi复合物中CB1 Ct的两种不同的合理模型。所得模型与核磁共振测定的CB1 Ct中间区域的螺旋结构（H9）一致。CB1 Ct直接与Gα和Gβ相互作用，并在Gi界面稳定受体。对CB1 Ct的Glu416Ct、Asp423Ct、Asp428Ct和arg444ct的定点诱变研究结果表明，CB1 Ct可以通过在Gi界面稳定受体来影响受体- G蛋白的偶联。这项研究首次提供了与G蛋白接触的CB1 Ct模型。蛋白质2016;84:532 - 543。©2016 Wiley期刊公司
Despite the important role of the carboxyl‐terminus (Ct) of the activated brain cannabinoid receptor one (CB1) in the regulation of G protein signaling, a structural understanding of interactions with G proteins is lacking. This is largely due to the highly flexible nature of the CB1 Ct that dynamically adapts its conformation to the presence of G proteins. In the present study, we explored how the CB1 Ct can interact with the G protein by building on our prior modeling of the CB1‐Gi complex (Shim, Ahn, and Kendall, The Journal of Biological Chemistry 2013;288:32449–32465) to incorporate a complete CB1 Ct (Glu416Ct–Leu472Ct). Based on the structural constraints from NMR studies, we employed ROSETTA to predict tertiary folds, ZDOCK to predict docking orientation, and molecular dynamics (MD) simulations to obtain two distinct plausible models of CB1 Ct in the CB1‐Gi complex. The resulting models were consistent with the NMR‐determined helical structure (H9) in the middle region of the CB1 Ct. The CB1 Ct directly interacted with both Gα and Gβ and stabilized the receptor at the Gi interface. The results of site‐directed mutagenesis studies of Glu416Ct, Asp423Ct, Asp428Ct, and Arg444Ctof CB1 Ct suggested that the CB1 Ct can influence receptor‐G protein coupling by stabilizing the receptor at the Gi interface. This research provided, for the first time, models of the CB1 Ct in contact with the G protein. Proteins 2016; 84:532–543. © 2016 Wiley Periodicals, Inc.