ION CHANNELS AND SIGNALING MECHANISMS IN T LYMPHOCYTES

描述(改编自申请人的描述)： 细胞内游离钙浓度是控制细胞内钙离子浓度的重要信号。 T淋巴细胞的分化和功能。这样做的长期目标是 建议阐明负责产生的分子机制 T细胞内钙信号的整形。T细胞中的CA2信号被产生到 这在很大程度上取决于钙释放激活的钙通道(CRAC)的活性。 这些通道响应于细胞内钙存储的耗尽而开放， 但是，将库存耗尽与渠道开放联系起来的机制并不完善 明白了。我们将测试CRAC通道激活的两种可能机制 使用电生理和荧光成像的组合 方法：通过以下方式调节开放通道插入质膜 囊泡融合，并通过物理耦合控制CRAC通道门控 储存膜蛋白。线粒体在维持一种 通过CRAC通道的高钙内流速率。为了进一步了解这一点 功能被执行时，我们将检查功能之间的相互作用 线粒体与CRAC通道和钙激活钾通道的关系 这与膜电位和钙内流的控制有关。最后，钙离子 质膜中的ATPase(PMCA)主要负责 清除T细胞中的钙离子，其活性受 [Ca~(2+)]的变化，使其增加了Ca~(2+)的复杂性 信号动力学。我们将应用一种新的胞浆钙钳技术 PMCA调控及其分子的钙依赖性和时间依赖性的表征 机制。 这些研究的意义是双重的。第一，CRAC频道，KCA频道， 线粒体和泵在不可兴奋的细胞中以各种形式广泛表达， 因此，更好地了解它们在T细胞中的运作和相互作用将有助于 许多细胞类型中的CA2信号机制。第二，钙信号的复杂性 已知在T细胞中是选择性调节下游的重要决定因素 免疫反应过程中的基因表达和细胞激活等反应。因此， 这项研究的结果可能有助于确定控制免疫反应的新靶点。 因此，这项研究的结果可能有助于确定控制免疫的新靶点 可能有益于治疗免疫缺陷的自身免疫性疾病的反应， 它们可能有助于解释由于禁食手术导致的免疫功能障碍。 通道、泵和线粒体。

DESCRIPTION (Adapted from applicant's Description): The elevation of intracellular free Ca2+ concentration is an essential signal controlling the differentiation and functions of T lymphocytes. The long-term goal of this proposal is to elucidate the molecular mechanisms responsible for generating the shaping Ca2+ signals in T Cells. Ca2+ signals in T cells are generated to a great extent by the activity of Ca2+ release-activated Ca2+ (CRAC) channels. These channels open in response to the depletion of intracellular Ca2+ stores, but the mechanism linking store depletion to channel opening is not well understood. We will test two possible mechanisms of CRAC channel activation using a combination of electrophysiological and fluorescence imaging approaches: regulated insertion of open channels into the plasma membrane by vesicle fusion, and control of CRAC channel gating by physical coupling to store membrane proteins. Mitochondria play an essential role in maintaining a high rate of Ca2+ influx through CRAC channels. To further understand how this function is carried out, we will examine the functional interactions between mitochondria and both CRAC channels and Ca2+-activated K+ channels, and relate this to the control of membrane potential and Ca2+ influx. Finally, Ca2+ ATPases in the plasma membrane (PMCA) are primarily responsible for the clearance of Ca2+ from T cells, and their activity is modulated slowly by changes in [Ca2+], allowing them to contribute to the complexity of Ca2+ signaling dynamics. We will apply a novel cytosolic calcium clamp technique to characterize the Ca2+- and time-dependence of PMCA modulation and its molecular mechanism. The significance of these studies is two-fold. First, CRAC channels, KCa channels, mitochondria, and pumps are widely expressed in various forms among non-excitable cells, so that a better understanding of their operation and interactions in T cells will shed light on Ca2+ signaling mechanisms in many cell types. Second, the complex nature of Ca2+ signals in T cells is known to be an important determinant for the selective regulation of downstream responses such as gene expression and cell activation during the immune response. Thus, the results of this study may help identify novel targets for the control of the immune response. Thus, the results of this study may help identify novel targets for the control of the immune response that may be beneficial in treating autoimmune disorders of immunodeficiencies, and they may help to explain immune dysfunctions resulting from the abberrant operation of channels, pumps and mitochondria.