Thermogenetic control of Ca2+ levels in cells and tissues

Virtually all major processes in cells and tissues are regulated by calcium ions (Ca2+). Understanding the influence of Ca2+ on cell function requires technologies that allow for non-invasive manipulation of intracellular calcium levels including the formation of calcium patterns, ideally in a way that is expandable to intact organisms. The currently existing tools for optical and optogenetic Ca2+ manipulation are limited with respect to response time, and tissue penetration depth. Here we present Genetically Encoded Calcium Controller (GECCO), a system for thermogenetic Ca2+ manipulation based on snake TRP channels optically controlled by infrared illumination. GECCO is functional in animal and plant cells and allows studying how cells decode different profiles of Ca2+ signals. GECCO enabled the shaping of insulin release from beta-cells, the identification of drugs that potentiate Ca2+-induced insulin release, and the generation of synthetic Ca2+ signatures in plants. ### Competing Interest Statement The authors have declared no competing interest.