Optogenetics and biosensors for dissecting cellular decision-making

/ABSTRACT The Toettcher laboratory seeks to understand how intracellular signaling pathways are organized and control outcomes such as gene expression, differentiation to specific fates and cell/tissue movement. To do so, we use innovative tools from synthetic biology: biosensors to measure pathway activity, optogenetics to control intracellular processes, and synthetic gene circuits to record and store information about each cell’s state. In recent years, we have developed new biosensors for endogenous receptor tyrosine kinases, constructed synthetic gene circuits for recording cells’ signaling states, and expanded the optogenetic toolbox by developing tools for light-controlled protein phase separation, gene expression, RNA degradation, and protein binding. We always seek to pair new tool development with applications in cell signaling and developmental biology. This approach has been fruitful, and our recent studies have shed light on how developmental signaling patterns are interpreted in early Drosophila embryo, how the body axis is established in 3D organoid models of mammalian embryogenesis, and how ERK signaling dynamics are regulated in cultured mammalian cells. Over the next five years, we propose to continue developing cutting-edge optogenetic tools and biosensors to probe and manipulate cells’ internal states. We will apply these tools in the Drosophila embryo to study how a developmental pattern can robustly generate the correct body plan in nearly all embryos, and how receptor tyrosine kinase activity is regulated by a novel feedback loop. We will use recording circuits to perform screens for regulators of ERK signaling dynamics, an important component of tissue movement and wound healing. Finally, we will continue to develop next-generation light-switchable and kinase-controlled proteins for cellular control. We expect that these approaches will have broad applications in understanding and controlling biological systems for fundamental discovery and in the design of next-generation cell therapies. Project Number: 1R35GM164185-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of General Medical Sciences (NIGMS) | Principal Investigator: Jared Toettcher | Institution: PRINCETON UNIVERSITY, Princeton, NJ | Award Amount: $369,000 | Activity Code: R35 | Study Section: Special Emphasis Panel[ZRG1 MCST-Q (55)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11331502