ATP release via anion channels.
ATP release via anion channels.
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ATP通过阴离子通道释放。
DOI：
10.1007/s11302-005-1557-0
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发表时间：
2005-12
影响因子：
3.5
通讯作者：
Okada, Yasunobu
中科院分区：
文献类型：
--
作者：
Sabirov, Ravshan Z;Okada, Yasunobu
三磷酸腺苷（ATP）不仅作为所有细胞类型的能量来源，还作为一种“细胞外信使”用于自分泌和旁分泌信号传导。它通过几种不同的嘌呤能信号外排途径从细胞中释放出来。在生理pH值下，ATP及其镁离子（Mg²⁺）和/或氢离子（H⁺）盐以阴离子形式存在，如果孔道在物理上允许，可能会通过一些阴离子通道离开细胞。在这篇综述中，我们综述了支持和反对ATP通过阴离子通道释放的实验数据。囊性纤维化跨膜传导调节因子（CFTR）长期以来被认为是气道上皮细胞和其他表达该蛋白的细胞中ATP释放的一种可能途径，尽管也观察到了非CFTR的ATP电流。容积敏感性外向整流（VSOR）氯离子通道几乎存在于所有细胞类型中，在某些实验条件下能够在物理上容纳甚至允许ATP⁴⁻通过。然而，药理学研究存在争议，并反对VSOR通道实际参与ATP的大量释放。一种大电导阴离子通道，其开放概率呈现钟形电压依赖性，也普遍存在，并代表了一种ATP释放的假定途径。这种通道被称为大阴离子通道，具有适合核苷酸运输的宽纳米孔，并且在孔腔中部具有一个ATP结合位点，以促进核苷酸的通过。大阴离子通道可传导ATP，并显示出与在渗透、缺血、缺氧和盐胁迫下ATP释放相似的药理学特征。还讨论了一些其他通道和转运体与ATP的调节性释放的关系。
ATP serves not only as an energy source for all cell types but as an ‘extracellular messenger-for autocrine and paracrine signalling. It is released from the cell via several different purinergic signal efflux pathways. ATP and its Mg2+ and/or H+ salts exist in anionic forms at physiological pH and may exit cells via some anion channel if the pore physically permits this. In this review we survey experimental data providing evidence for and against the release of ATP through anion channels. CFTR has long been considered a probable pathway for ATP release in airway epithelium and other types of cells expressing this protein, although non-CFTR ATP currents have also been observed. Volume-sensitive outwardly rectifying (VSOR) chloride channels are found in virtually all cell types and can physically accommodate or even permeate ATP4- in certain experimental conditions. However, pharmacological studies are controversial and argue against the actual involvement of the VSOR channel in significant release of ATP. A large-conductance anion channel whose open probability exhibits a bell-shaped voltage dependence is also ubiquitously expressed and represents a putative pathway for ATP release. This channel, called a maxi-anion channel, has a wide nanoscopic pore suitable for nucleotide transport and possesses an ATP-binding site in the middle of the pore lumen to facilitate the passage of the nucleotide. The maxi-anion channel conducts ATP and displays a pharmacological profile similar to that of ATP release in response to osmotic, ischemic, hypoxic and salt stresses. The relation of some other channels and transporters to the regulated release of ATP is also discussed.