Department of Chemistry, University of California, Berkeley, CA 94720, USA.
Proc Natl Acad Sci U S A. 2011 Apr 12;108(15):5980-5. doi: 10.1073/pnas.1009932108. Epub 2011 Mar 28.
Dynamic fluxes of s-block metals like potassium, sodium, and calcium are of broad importance in cell signaling. In contrast, the concept of mobile transition metals triggered by cell activation remains insufficiently explored, in large part because metals like copper and iron are typically studied as static cellular nutrients and there are a lack of direct, selective methods for monitoring their distributions in living cells. To help meet this need, we now report Coppersensor-3 (CS3), a bright small-molecule fluorescent probe that offers the unique capability to image labile copper pools in living cells at endogenous, basal levels. We use this chemical tool in conjunction with synchotron-based microprobe X-ray fluorescence microscopy (XRFM) to discover that neuronal cells move significant pools of copper from their cell bodies to peripheral processes upon their activation. Moreover, further CS3 and XRFM imaging experiments show that these dynamic copper redistributions are dependent on calcium release, establishing a link between mobile copper and major cell signaling pathways. By providing a small-molecule fluorophore that is selective and sensitive enough to image labile copper pools in living cells under basal conditions, CS3 opens opportunities for discovering and elucidating functions of copper in living systems.
在细胞信号转导中，像钾、钠和钙这样的 s 区金属的动态通量具有广泛的重要性。相比之下，细胞激活引发的可动过渡金属的概念仍未得到充分探索，这在很大程度上是因为铜和铁等金属通常被视为静态细胞营养物质进行研究，并且缺乏直接、选择性的方法来监测它们在活细胞中的分布。为了满足这一需求，我们现在报告了 Coppersensor-3（CS3），这是一种明亮的小分子荧光探针，具有独特的能力，可以在活细胞的内源性基础水平下对不稳定的铜池进行成像。我们使用这种化学工具结合基于同步加速器的微探针 X 射线荧光显微镜（XRFM），发现神经元细胞在激活时将大量的铜从细胞体转移到周边突起。此外，进一步的 CS3 和 XRFM 成像实验表明，这些动态铜再分布依赖于钙释放，从而在可动铜和主要细胞信号通路之间建立了联系。通过提供一种小分子荧光团，它足够选择性和灵敏，可以在基础条件下对活细胞中的不稳定铜池进行成像，CS3 为发现和阐明铜在活系统中的功能提供了机会。
