STIM1 is a calcium sensor specialized for digital signaling.
STIM1 is a calcium sensor specialized for digital signaling.
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DOI：
10.1016/j.cub.2009.08.022
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发表时间：
2009-11-03
期刊：
影响因子：
--
通讯作者：
Putney JW Jr
中科院分区：
文献类型：
--
作者：
Bird GS;Hwang SY;Smyth JT;Fukushima M;Boyles RR;Putney JW Jr
当细胞被低生理浓度的钙动员激动剂激活时，产生的钙信号通常采取储存钙的重复再生放电的形式，称为钙振荡。这些细胞内钙振荡长期以来一直令生物学家着迷，因为它们代表了数字化细胞内信号传导的模式。最近的工作强调了钙流入作为钙振荡重要组成部分的作用。这种流入是通过称为钙库操纵的钙进入的过程发生的，该过程是由内质网中的钙传感器蛋白 STIM1 和 STIM2 启动的。 STIM2 是通过接近静息水平的内质网钙的变化来激活的，而激活 STIM1 需要达到钙消耗的阈值。在这项研究中，我们令人惊讶地发现，在钙振荡过程中，专门参与钙进入的是 STIM1，而不是 STIM2。这意味着每次振荡都会产生内质网钙的瞬时下降，足以瞬时激活 STIM1。通过全内反射荧光显微镜可以在某些细胞中观察到 STIM1 的瞬时激活。这种安排很好地提供了一个明确定义和明确的信号系统，将数字钙释放信号转化为可以向下游效应器发出信号的钙流入。
When cells are activated by calcium-mobilizing agonists at low, physiological concentrations, the resulting calcium signals generally take the form of repetitive regenerative discharges of stored calcium, termed calcium oscillations. These intracellular calcium oscillations have long fascinated biologists as representing a mode of digitized intracellular signaling. Recent work has highlighted the role of calcium influx as an essential component of calcium oscillations. This influx occurs through a process known as store-operated calcium entry which is initiated by calcium sensor proteins in the endoplasmic reticulum, STIM1 and STIM2. STIM2 is activated by changes in endoplasmic reticulum calcium near the resting level, while a threshold of calcium depletion is required to activate STIM1. In this study, we show that, surprisingly, it is STIM1 and not STIM2 that is exclusively involved in calcium entry during calcium oscillations. The implication is that each oscillation produces a transient drop in endoplasmic reticulum calcium that is sufficient to transiently activate STIM1. This transient activation of STIM1 can be observed in some cells by total internal reflection fluorescence microscopy. This arrangement nicely provides a clearly defined and unambiguous signaling system, translating a digital calcium release signal into calcium influx that can signal to downstream effectors.
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影响因子：
4.1
作者：
COOPER, DMF;YOSHIMURA, M;MAHEY, R
通讯作者：
MAHEY, R
影响因子：
4.8
作者：
Mercer, Jason C.;DeHaven, Wayne I.;Putney, James W., Jr.
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Putney, James W., Jr.
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Parekh, Anant B.
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5.5
作者：
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