Rewiring a Calcium-Dependent Signaling Pathway in Mammalian Cells

Methods for controlling and regulating cellular processes are of key importance in the basic research of cell biology and understanding of cellular mechanisms. Synthetic systems for regulation of gene expression are often developed based on known cell signaling pathways. Calcium-dependent regulation is an attractive approach for achieving such control, as diverse stimuli induce calcium influx by activating membrane receptors. Here, we employed engineered NFAT transcription factors to induce the potent and robust activation of exogenous gene expression in mammalin cells. Furthermore, we designed a calcium-dependent transcription factor that does not interfere with NFAT-regulated promoters and potently activates transcription in several mammalian cell types. Additionally, we demonstrate that coupling the circuit to a calcium-selective ion channel resulted in capsaicin- and temperature-controlled gene expression. This engineered calcium-dependent signaling pathway enables tightly controlled regulation of gene expression through different stimuli in mammalian cells and is versatile, adaptable, and useful for a wide range of therapeutic and diagnostic applications.