The Collective Power of Genetically Encoded Protein/Peptide Tags and Bioorthogonal Chemistry in Biological Fluorescence Imaging

Abstract

AbstractGenetically encoded protein or peptide tags and bioorthogonal chemistry are two growing classes of tools in cell biological research. A protein or peptide tag could be genetically fused to a protein of interest (POI) in the same manner as fluorescent proteins (FPs). An enzymatic ligation step would then follow to deliver a chemical entity, such as a dye or a probe with properties unattainable from FPs, to the tag, and consequently to the tethered POI. Bioorthogonal chemistry refers to a collection of (mostly) bimolecular conjugation reactions that are fine‐tuned to occur efficiently in a biological environment without the interference to or from the resident (bio)molecules or ions. These two areas of research have been developed independently and more or less concurrently. The combined use of them could expand the utilities of both tools, which is advocated in this Review. The mechanisms and utilities of protein or peptide tags and bioorthogonal chemistry are briefly reviewed separately in the first two sections, while in the third section the examples that utilize both protein or peptide tags and bioorthogonal chemistry are enumerated. Each tool and the strategy of their deployment carry their own advantages and disadvantages, and the selection of a particular tool depends on a given problem. The advances and combined use of the two topical areas are driven by the emerging challenges in illuminating the ever‐finer details of biological structures and actions.