Functional Characterization of an Electromagnetic Perceptive Protein

Abstract

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 animal models. Here, we report for the first time the cellular location and orientation of the EPG protein. We utilized a differential labelling technique in determining 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 stimulation 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. These data serve to provide additional information that support and understand the underlying biophysical mechanisms behind EPG activation by magnetic stimulation. In conclusion, our results provide evidence for the basis of magnetoreception in EPG protein that would aid in future studies that seek to understand this novel mechanism. This study is important for understanding the phenomenon of magnetoreception as well as developing new technologies for magnetogenetics – the utilization of electromagnetic fields to remotely control cellular function.Graphical TOCElucidation of magnetoreception in a fish derived Electromagnetic Perceptive Gene (EPG), using genetic tagging and single particle tracking with Total Internal Reflection Fluorescence (TIRF) suggests changes in kinetics of membranal motion upon stimulation by magnetic field.

A putative design for electromagnetic activation of split proteins for molecular and cellular manipulation

“…Therefore, we anticipated cytoplasmic expression. To test this hypothesis, we co-expressed the EPG BRET construct as well as an EPG HaloTag construct that was previously shown to be membrane anchored in mammalian cells 26 . Fluorescent images show the BRET construct was likely expressed in the cytoplasm as opposed to the EPG HaloTag fusion protein that is mostly observed on the cellular membrane.…”

Bioelectromagnetic Platform for Cell, Tissue, and In Vivo Stimulation

“…High costs of bioelectromagnetic stimulation devices and a lack of systematic analysis of electromagnetic stimulus fields serve as a barrier to designing quantitative studies and replicating results in magnetogenetics experiments. Development of magnetic sensitive pathways, like those using nanoparticles [2] and proteins like the electromagnetic perceptive gene (EPG) [3][4][5][6][7], have contributed to making magnetic stimulus delivery for wide ranging applications increasingly important. Furthermore, recent studies which show that humans may also have magnetoperception [8] serve to increase the demand for easy to implement and versatile electromagnetic stimulation devices.…”

Bioelectromagnetic platform for stimulation

“…Development of magnetic sensitive pathways, like those using nanoparticles (Chen et al, 2015) and proteins like the electromagnetic perceptive gene (EPG) (Krishnan et al, 2018;Mitra et al, 2020;Cywiak et al, 2020;Hwang et al, 2020;Hunt et al, 2021) have contributed to making magnetic stimulus delivery for wide ranging applications increasingly important. Furthermore, recent studies which show that humans may also have magnetoperception (Wang et al, 2019) serve to increase the demand for easy to implement and versatile electromagnetic stimulation devices.…”