Development of a Two-Component System for Signal Propagation in Plants

Our objective is to engineer orthogonal signal propagation circuits in plants. One approach to this is the development of binary (or two-component) systems based on customized transcription factors. Transcription Activator-like Effectors (TALEs) and CRISPR/Cas nucleases are proteins with programmable sequence specific DNA binding, forming the basis for orthogonal DNA binding specificity in a given host organism. The transcription-based two component systems we designed are inspired by the yeast two-hybrid assay, where a DNA binding domain and a transcription activation domain are brought together via protein-protein interaction. For signal propagation, DNA binding units based on TALEs or CRISPR/Cas can be constitutively expressed and can interact with an independently expressed activation unit. By conferring intercellular mobility to the activation unit, signal propagation can be achieved. We will present our design strategies and recent results for the engineering of binary transcription activation for signal propagation.