A Live-Cell Analytical Platform by Using Strigolactones-Induced Dimerization System

Chemical-induced dimerization (CID) offers a strategy for constructing live-cell analytical platforms by enabling chemically programmable perturbations. However, widely used CID systems often lack orthogonality, exhibit complex concentration-dependent behaviors, or interact with endogenous pathways, limiting their suitability for intracellular analysis. Here, we report a CID system based on the strigolactones (SLs) signaling pathway and developed a live-cell analytical platform using the SLs-induced dimerization (SLs-CID) system. In this study, we used the strigolactones analog GR24 to induce the dimerization between DAD2 and an optimized receptor variant, MAX2₅₁₄. We systematically investigated the performance of SLs-based CID systems, and the results demonstrated that this system exhibits high specificity, good orthogonality, reversibility, minimal cytotoxicity, and saturable kinetics. Furthermore, we proposed an approach for in situ monitoring Caspase-3 activity in single living cells based on the SLs-based CID system for precisely modulating protein distribution. Finally, combining the SLs-based CID platform with single-molecule fluorescence triple-correlation spectroscopy (FTCS), we constructed an intracellular "AND" logic gate. The results showed that this logic gate enables high-specificity analytical readout. Together, our results illustrated that the SLs-induced dimerization system is a versatile and robust tool for implementing controlled intracellular perturbations and sensing cellular activities, thereby enabling live-cell analysis within a chemically programmable framework.