Intracellular Ca2+-uptake and its contribution to signalling

钙是真核细胞中最常见的第二信使，通常认为钙信号的特异性可以通过细胞内钙离子浓度的时空变化来实现。这些对不同刺激作出反应的钙信号是调节胞内钙离子进出的通道和转运蛋白的组合和严格调控的结果。我们的目标是了解单个细胞内钙的储存和运输系统如何影响[钙]细胞瞬变的空间和时间特征。我们已经将所谓的Gecos添加到工具箱中，这是一种新型的基于强度的钙传感器，具有非常高的动态范围，有不同的颜色可供选择，现在能够生成本地和系统根中钙离子响应的高分辨率图谱。我们的重点将是确定液泡钙的释放是否以及如何有助于钙信号。通过组合表达光谱不同的Geco，我们将能够同时测量不同隔室的钙动态，并通过将Gecos与ROS和pH传感器相结合，我们计划阐明这些重要信号分子之间的时间和空间关系。此外，通过细胞类型特异性和诱导性的钙诱骗表达，我们计划干扰局部和全身的钙反应。

Calcium is the most common second messenger in eukaryotic cells and it is generally assumed that specificity in Ca2+ signalling can be achieved by stimulus-specific, spatio-temporally distinct changes in cytosolic Ca2+ concentrations. Such Ca2+ signatures in response to different stimuli are the result of the combined and tightly regulated activities of channels and transporters that mediatein- and efflux of cytosolic Ca2+. Our objective is to understand how individual intracellular Ca2+-stores and transport systems contribute to the spatial and temporal characteristics of [Ca2+]cyttransients. We have added the so-called GECOs, a novel class of intensity based Ca2+ sensors with a very high dynamic range and available in different colours to the toolbox and are now able to generate a high-resolution atlas of both local and systemic Ca2+-responses in roots. Our particular focus will be to determine if and how release of vacuolar calcium contributes to Ca2+-signatures. By combinatorial expression of spectrally distinct GECOs we will be able to simultaneously measure Ca2+-dynamics in different compartments and by combining GECOs with sensors for ROS and pH we plan to elucidate the temporal and spatial relationships among these important signalling molecules. Furthermore, by cell-type specific and inducible expression of calcium decoys we plan to interfere with local and systemic Ca2+-responses.