Activation mechanism of the μ-opioid receptor by an allosteric modulator.
Activation mechanism of the μ-opioid receptor by an allosteric modulator.
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DOI：
10.1073/pnas.2121918119
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发表时间：
2022-04-19
影响因子：
11.1
通讯作者：
中科院分区：
文献类型：
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变构调节剂与非正构位点结合，增强g蛋白偶联受体（gpcr）的信号活性，是gpcr靶向药物的新候选物。我们对μ-阿片受体（MOR）的溶液核磁共振分析表明，MOR的活性是由三个构象之间的构象平衡决定的。有趣的是，一种变构调节剂将平衡转向具有最高活性的构象，这是单靠正构配体无法达到的，从而导致MOR活性增加。我们的核磁共振分析还确定了变构调节剂的结合位点，包括有助于调节平衡的残基。这些发现为新型变构调节剂的合理发展提供了见解。g蛋白偶联受体（gpcr）的变构调节剂通过与其正构配体同时结合来增强信号传导，为克服传统正构配体的功效局限性提供了一种新的方法。然而，变构调节剂介导GPCR信号传导的结构机制在很大程度上仍然未知。为了阐明变构调节剂激活μ-阿片受体（MOR）的机制，我们通过监测蛋氨酸甲基的信号对MOR进行了溶液核磁共振分析。我们发现MOR的胞内侧存在于三种不同活性构象之间的平衡状态。有趣的是，平衡中的种群决定了MOR的表观信号活性。我们的分析还显示，即使在完全激动剂结合状态下，平衡也没有完全转移到具有最高活性的构象，其中细胞内的一半TM6向外移动。令人惊讶的是，MOR的变构调节剂BMS-986122将平衡向具有最高活性的构象转移，导致MOR在完全激动剂结合状态下的活性增加。我们还确定BMS-986122与TM3上T162周围跨膜区域的一个间隙结合。综上所述，BMS-986122与TM3的结合通过重新排列TM3与TM6的直接相互作用，从而使TM6稳定在有利于g蛋白结合的外移位置，从而提高了MOR的活性。这些发现揭示了新型变构调节剂的合理发展，这种调节剂比单独的正构配体更能激活gpcr，并为下一代gpcr靶向治疗铺平了道路。
The allosteric modulators, which bind to nonorthosteric sites to enhance the signaling activities of G-protein-coupled receptors (GPCRs), are new candidates for GPCR-targeting drugs. Our solution NMR analyses of the μ-opioid receptor (MOR) revealed that the MOR activity was determined by a conformational equilibrium between three conformations. Interestingly, an allosteric modulator shifted the equilibrium toward a conformation with the highest activity to a level that cannot be reached by orthosteric ligands alone, leading to the increased activity of MOR. Our NMR analyses also identified the binding site of the allosteric modulator, including the residues contributing to the regulation of the equilibrium. These findings provide insights into the rational developments of novel allosteric modulators. Allosteric modulators of G-protein-coupled receptors (GPCRs) enhance signaling by binding to GPCRs concurrently with their orthosteric ligands, offering a novel approach to overcome the efficacy limitations of conventional orthosteric ligands. However, the structural mechanism by which allosteric modulators mediate GPCR signaling remains largely unknown. Here, to elucidate the mechanism of μ-opioid receptor (MOR) activation by allosteric modulators, we conducted solution NMR analyses of MOR by monitoring the signals from methionine methyl groups. We found that the intracellular side of MOR exists in an equilibrium between three conformations with different activities. Interestingly, the populations in the equilibrium determine the apparent signaling activity of MOR. Our analyses also revealed that the equilibrium is not fully shifted to the conformation with the highest activity even in the full agonist-bound state, where the intracellular half of TM6 is outward-shifted. Surprisingly, an allosteric modulator for MOR, BMS-986122, shifted the equilibrium toward the conformation with the highest activity, leading to the increased activity of MOR in the full agonist-bound state. We also determined that BMS-986122 binds to a cleft in the transmembrane region around T162 on TM3. Together, these results suggest that BMS-986122 binding to TM3 increases the activity of MOR by rearranging the direct interactions of TM3 and TM6, thus stabilizing TM6 in the outward-shifted position which is favorable for G-protein binding. These findings shed light on the rational developments of novel allosteric modulators that activate GPCRs further than orthosteric ligands alone and pave the way for next-generation GPCR-targeting therapeutics.
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影响因子：
64.8
作者：
Koehl A;Hu H;Maeda S;Zhang Y;Qu Q;Paggi JM;Latorraca NR;Hilger D;Dawson R;Matile H;Schertler GFX;Granier S;Weis WI;Dror RO;Manglik A;Skiniotis G;Kobilka BK
通讯作者：
Kobilka BK
DOI：
10.1038/nrd2760
发表时间：
2009-01
期刊：
Nature reviews. Drug discovery
影响因子：
--
作者：
通讯作者：
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影响因子：
7.3
作者：
Burford, Neil T.;Livingston, Kathryn E.;Alt, Andrew
通讯作者：
Alt, Andrew
DOI：
10.1126/science.1215802
发表时间：
2012-03-02
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Liu JJ;Horst R;Katritch V;Stevens RC;Wüthrich K
通讯作者：
Wüthrich K
影响因子：
16.6
作者：
通讯作者：
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