Ultrasonic Control\nof Protein Splicing by Split Inteins

Utilizing ultrasound as an external stimulus to remotely\nmodulate\nthe activity of proteins is an important aspect of sonopharmacology\nand establishes the basis for the emerging field of sonogenetics.\nHere, we describe an ultrasound-responsive protein splicing system\nthat enables spatiotemporal control of split-intein-mediated protein\nligation. The system utilizes engineered split inteins that are caged\nand can be activated by thrombin released from a high molar mass DNA-based\ncarrier under focused ultrasound sonication. This approach represents\na general method for controlling the functions of proteins of interest\nby ultrasound, as demonstrated here by the controlled synthesis of\nthe superfolder green fluorescence protein (GFP) and calcitonin. Furthermore,\ncalcitonin receptor-mediated signal transduction in cells was triggered\nby this system in vitro without harming cell viability. By expanding\nthe sonogenetic toolbox with protein splicing technologies, this study\nprovides a possible pathway to deploy ultrasound for remotely controlling\na variety of protein functions in deep tissue in the future.