Do biased agonists at the mu-opioid receptor induce different patterns of receptor phosphorylation?

mu-阿片受体的偏向激动剂是否会诱导不同的受体磷酸化模式？

• 批准号: BB/J003506/1
• 负责人: Eamonn Kelly
• 金额: $ 40.09万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FJ003506%2F1
• 关键词: Do; biased; agonists; mu; opioid

The mu-opioid receptor (MOPr) is a protein receptor found in the membrane of certain nerve cells in the brain and spinal cord. It interacts with (i.e. is receptive to) chemicals such as endorphins and enkephalins in the body causing a reduction in the electrical excitability of the nerve cells. In the whole organism, this leads to a number of outcomes, most notably the relief of pain, although MOPr also controls a number of other processes including mood and emotion, secretions in the stomach and intestine, the rate of breathing, and body temperature. The MOPr is therefore a very important receptor and consequently over the years many chemical compounds (ligands) have been made that can interact with this receptor. Although many of these ligands seem to produce similar effects when they interact with MOPr, we have recently found that some ligands interact with the receptor to produce significantly different effects from others. This can be seen as one ligand strongly activating one particular intracellular signaling pathway rather than another, whereas another ligand might activate the latter pathway more strongly. This phenomenon has been called 'biased agonism', but as yet the mechanisms involved in producing biased agonism are not known. We think that what happens is that the different ligands are able to bind to the MOPr and make the receptor take up different shapes. This not only makes the MOPr susceptible to a chemical process called phosphorylation, but the phosphorylation can take place on different parts of the MOPr, depending upon which ligand it is interacting with. Phosphorylation is where chemical groups called phosphate groups are added to a protein, and phosphorylation normally leads to the protein changing its function in some way, or the rate at which it does something. Phosphorylation of MOPr leads to it becoming less active in some regards, but more active in others. We think that different MOPr ligands make it become phosphorylated in different ways and this leads to distinct cell signaling outputs. This is what we want to measure in this proposal - we want to investigate whether different ligands phosphorylate MOPr in different ways, and whether this leads to different signaling and hence different effects in the organism. Knowledge gained from this work will allow us regard receptors such as MOPr in a completely new way, meaning that we could make ligands that bind to the same receptor (MOPr), but can lead to different effects in the whole organism. In addition, this phemomenon is likely to occur for many of the other types of related receptor (>800 in the mammalian genome) and so the MOPr can be used as an excellent model system to test out our hypothesis. The major aims of this work are therefore to: (1) identify exactly which parts of MOPr are phosphorylated when it interacts with different ligands (2) use this knowledge to make antibodies that will recognize the phosphorylated MOPr and use them to see how different ligands might produce different phosphorylation events on the receptor (3) investigate using cell imaging technology whether there is a correlation between the amount and type of phosphorylation of MOPr and where the MOPr is located in a nerve cell (4) investigate whether and how MOPr in brain is phosphorylated (5) identify the different cellular signals that biased ligands at MOPr might produce

μ-阿片受体（MOPr）是一种在脑和脊髓中某些神经细胞膜中发现的蛋白质受体。它与体内的内啡肽和脑啡肽等化学物质相互作用（即接受），导致神经细胞的电兴奋性降低。在整个生物体中，这导致了许多结果，最明显的是疼痛的缓解，尽管MOPr也控制着许多其他过程，包括情绪和情感，胃和肠中的分泌物，呼吸频率和体温。因此，MOPr是一种非常重要的受体，因此多年来已经制备了许多可以与这种受体相互作用的化合物（配体）。虽然许多这些配体似乎产生类似的效果，当它们与MOPr相互作用，我们最近发现，一些配体与受体相互作用，产生显着不同的效果从其他人。这可以被看作是一种配体强烈激活一种特定的细胞内信号传导途径而不是另一种，而另一种配体可能更强烈地激活后一种途径。这种现象被称为“偏向激动”，但迄今为止，参与产生偏向激动的机制尚不清楚。我们认为不同的配体能够与MOPr结合，使受体呈现不同的形状。这不仅使MOPr对称为磷酸化的化学过程敏感，而且磷酸化可以发生在MOPr的不同部分，这取决于它与哪种配体相互作用。磷酸化是一种被称为磷酸基团的化学基团被添加到蛋白质中，磷酸化通常会导致蛋白质以某种方式改变其功能，或者改变其做某事的速度。MOPr的磷酸化导致它在某些方面变得不那么活跃，但在其他方面更活跃。我们认为不同的MOPr配体使其以不同的方式磷酸化，这导致不同的细胞信号输出。这就是我们在这个提议中想要测量的-我们想要研究不同的配体是否以不同的方式磷酸化MOPr，以及这是否会导致不同的信号传导，从而在生物体中产生不同的影响。从这项工作中获得的知识将使我们能够以一种全新的方式看待MOPr等受体，这意味着我们可以制造与同一受体（MOPr）结合的配体，但可以在整个生物体中产生不同的作用。此外，这种现象可能发生在许多其他类型的相关受体（哺乳动物基因组中>800）上，因此MOPr可以用作一个很好的模型系统来验证我们的假设。因此，这项工作的主要目标是：（1）当MOPr与不同的配体相互作用时，准确地识别MOPr的哪些部分被磷酸化（2）使用这些知识来制造能够识别磷酸化MOPr的抗体，并使用它们来观察不同的配体如何在受体上产生不同的磷酸化事件（3）使用细胞成像技术研究MOPr的磷酸化的量和类型与MOPr在神经细胞中的位置之间是否存在相关性（4）研究脑中的MOPr是否被磷酸化以及如何被磷酸化（5）鉴定MOPr处的偏向配体可能产生的不同细胞信号

项目成果

The opioid receptor pharmacology of GSK1521498 compared to other ligands with differential effects on compulsive reward-related behaviours.

• DOI: 10.1007/s00213-014-3666-3
• 发表时间: 2015-01
• 期刊: PSYCHOPHARMACOLOGY
• 影响因子: 3.4
• 作者: Kelly, Eamonn;Mundell, Stuart J.;Sava, Anna;Roth, Adelheid L.;Felici, Antonio;Maltby, Kay;Nathan, Pradeep J.;Bullmore, Edward T.;Henderson, Graeme
• 通讯作者: Henderson, Graeme

The Concise Guide to PHARMACOLOGY 2015/16: G protein-coupled receptors.

• DOI: 10.1111/bph.13348
• 发表时间: 2015-12
• 期刊: British journal of pharmacology
• 影响因子: 7.3
• 作者: Alexander SP;Davenport AP;Kelly E;Marrion N;Peters JA;Benson HE;Faccenda E;Pawson AJ;Sharman JL;Southan C;Davies JA;CGTP Collaborators
• 通讯作者: CGTP Collaborators