Photoactivatable trimethoprim-based probes for spatiotemporal control of biological processes

Optogenetic tools allow regulation of cellular processes with light, which can be delivered with spatiotemporal resolution. By combining the chemical versatility of photoremovable protecting groups with the biological specificity of self-labeling tags, we developed a series of chemi-optogenetic tools that enable protein recruitment with precise spatiotemporal control. To this end, we created a modular platform for chemically inducible proximity (CIP), a technique in which two proteins of interest are brought together by the presence of a small molecule to induce a biological effect. The local proximity of a protein and its substrate has been shown to be sufficient to initiate a desired biological effect, making CIP a valuable technique towards probing cellular processes. The high affinity and specificity of these tags result in rapid initiation of dimerization, allowing biochemical processes to be studied on a biologically relevant timescale. In this chapter, we describe the synthesis and application of chemi-optogenetic probes for spatiotemporal control of protein proximity.