Magnetoreception, the response to geomagnetic fields is a well described phenomenon in nature. However, it is likely that convergent evolution led to different mechanisms in different organisms. One intriguing example is the unique Electromagnetic Perceptive Gene (EPG) from the glass catfish Kryptopterus vitreolus, that can remotely control cellular function, upon magnetic stimulation in in-vitro and in-vivo. Here, we report for the first time the cellular location and orientation of the EPG protein. We utilized a differential labelling technique to determine that the EPG protein is a membrane anchored protein with an N-terminal extracellular domain. The kinetics and diffusion dynamics of the EPG protein in response to magnetic stimulation was also elucidated using single particle imaging and tracking. Pulse chase labelling and Total Internal Reflection Fluorescence (TIRF) imaging revealed an increase in EPG kinetics post magnetic activation at a single particle level. Trajectory analysis show notably different EPG protein kinetics before and after magnetic stimulation in both 2 (free vs bound particle) and 3 state (free vs intermediate vs bound particle) tracking models. This data provides additional information to support and understand the underlying biophysical mechanisms behind EPG activation by magnetic fields and provides evidence for the basis of magnetoreception in the EPG protein that will aid in future studies that seek to further understand this novel mechanism. This study is important for understanding magnetoreception as well as developing new technologies for magnetogenetics – the utilization of electromagnetic fields to remotely control cellular function.

中文翻译：

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电磁感知蛋白的功能表征

磁感应，对地磁场的响应是自然界中描述得很清楚的现象。但是，趋同进化可能导致不同生物体的机制不同。一个有趣的例子是玻璃cat鱼Kryptopterus vitreolus的独特电磁感知基因（EPG），在体外和体内进行磁刺激后，它可以远程控制细胞功能。。在这里，我们首次报告了EPG蛋白的细胞定位和方向。我们利用差异标记技术来确定EPG蛋白是具有N末端胞外域的膜锚定蛋白。使用单个粒子成像和跟踪还阐明了EPG蛋白响应磁刺激的动力学和扩散动力学。脉冲追逐标记和全内反射荧光（TIRF）成像显示在单个粒子水平上磁激活后，EPG动力学增加。轨迹分析显示，在2种状态（游离粒子与结合粒子）和3种状态（游离粒子与中间粒子与结合粒子）跟踪模型中，磁刺激前后的EPG蛋白动力学显着不同。该数据提供了更多信息，以支持和理解EPG磁场激活背后的潜在生物物理机制，并为EPG蛋白的磁感受基础提供了证据，这将有助于寻求进一步了解这一新机制的未来研究。这项研究对于理解磁感受以及开发磁致磁学新技术（利用电磁场远程控制细胞功能）具有重要意义。