The Cell Biology Of ATP Signalling At Intracellular P2X Receptors

细胞内 P2X 受体 ATP 信号转导的细胞生物学

• 批准号: BB/F023588/1
• 负责人: Samuel Fountain
• 金额: $ 101.28万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FF023588%2F1
• 关键词: Cell; Biology; ATP; Signalling; Intracellular

ATP is an energy source used inside every cell in our bodies but is also released by cells allowing cells to communicate with one another. ATP released from cells binds to and opens receptors on the cell surface, called P2X receptors. Once open these receptors allow sodium and calcium to flow into the cell resulting in the activation of further processes. In animals, P2X receptors are present on the cell surface on nerves, immune cells and muscle, they consequently are involved in sensing pain, inflammation and the control of blood flow. It is the overall aim of our research to understand P2X receptors better in order to develop pain relieving and anti-inflammatory therapies in humans. We recently identified a new P2X receptor, called DdP2X, in a species of amoeba. This was the first time a P2X receptor had been found in a single celled organism. In contrast to animal P2X receptors DdP2X was found inside the cell and not at the cell surface. DdP2X was present on a specialised organelle inside the amoeba called a vacuole. The vacuole is responsible for pumping out excess water entering the cell, which allows the amoeba to regulate its volume. In order to understand the role of DdP2X, we generated amoeba lacking DdP2X by removing the gene that makes it. Amoeba lacking DdP2X could not pump water out as effectively and consequently swelled when placed in water. This observation suggested that DdP2X is required for the vacuole to function correctly. One of the major goals of this proposal is too understand how DdP2X regulates vacuole function in amoeba. This findings of this research may inform us of how P2X receptors may regulate vacuoles in human cells. We will identify whether calcium moving through DdP2X is essential for correct vacuole function and excretion of water. We will also identity other proteins that are associated with DdP2X. This will help us to understand how the receptor is localised to the inside of the cell and identify the molecules inside the cell that regulate or are regulated by DdP2X. The second major focus of this study is to understand how P2X receptors work and their evolution. We have now identified several other primitive P2X receptors in singled celled organisms like green algae. Primitive P2X receptors are useful tools for understand how receptor structure relates to function. This is because primitive P2X receptors share only few similarities with human, mouse and rat receptors and therefore comparing and manipulating them will reveal the critical parts that are required for a P2X receptor to work as an ATP-binding ion channel. We ultimately want to understand the parts of P2X receptors that bind pain relieving drugs. In summary, we will us amoeba as a model cell to investigate the functions that P2X receptors play inside the cell. Experiments using P2X receptors from single celled organisms will be used to inform us of how human P2X receptors function in health and disease.

ATP是我们体内每个细胞使用的一种能量来源，但也由细胞释放，使细胞之间能够相互交流。细胞释放的ATP结合并打开细胞表面的受体，称为P2X受体。一旦打开，这些受体允许钠和钙流入细胞，从而激活进一步的过程。在动物中，P2X受体存在于神经、免疫细胞和肌肉的细胞表面，因此它们参与感知疼痛、炎症和血流控制。我们研究的总体目标是更好地了解P2X受体，以便开发人类疼痛缓解和抗炎疗法。我们最近在一种变形虫体内发现了一种新的P2X受体，叫做DdP2X。这是首次在单细胞生物中发现P2X受体。与动物P2X受体相反，DdP2X在细胞内而不是在细胞表面被发现。DdP2X存在于变形虫内部一个叫做液泡的特殊细胞器上。液泡负责抽出进入细胞的多余水分，这使得变形虫能够调节自己的体积。为了了解DdP2X的作用，我们通过去除产生DdP2X的基因来产生缺乏DdP2X的变形虫。缺乏DdP2X的变形虫不能有效地泵出水分，因此当放置在水中时，变形虫会膨胀。这一观察结果表明，DdP2X是液泡正常工作所必需的。该提案的主要目标之一是了解DdP2X如何调节变形虫的液泡功能。本研究的发现可能会告诉我们P2X受体如何调节人类细胞中的液泡。我们将确定钙通过DdP2X的移动是否对正确的液泡功能和水的排泄至关重要。我们还将鉴定与DdP2X相关的其他蛋白质。这将帮助我们了解受体是如何定位到细胞内部的，并识别细胞内调节或受DdP2X调节的分子。本研究的第二个重点是了解P2X受体如何工作及其进化。我们现在已经在绿藻等单细胞生物中发现了其他几种原始的P2X受体。原始P2X受体是了解受体结构与功能关系的有用工具。这是因为原始的P2X受体与人类、小鼠和大鼠的受体只有很少的相似之处，因此比较和操纵它们将揭示P2X受体作为atp结合离子通道所需的关键部分。我们最终想要了解P2X受体结合止痛药物的部分。综上所述，我们将以变形虫为模型细胞来研究P2X受体在细胞内的功能。使用来自单细胞生物的P2X受体的实验将用于告诉我们人类P2X受体如何在健康和疾病中发挥作用。