Advances in chemical labeling of proteins in living cells

Abstract

Summary The pursuit of quantitative biological information with imaging requires robust labeling approaches that can be used in multiple applications and with a variety of detectable colors and properties. In addition to conventional fluorescent proteins, chemists and biologists have come together to provide a range of approaches that combine dye chemistry with the convenience of genetic targeting. This hybrid-tagging approach combines the rational design of properties available through synthetic dye chemistry with the robust biological targeting available with genetic encoding. In this review, we discuss the current range of approaches that have been exploited for dye targeting, or targeting and activation, and some of the recent applications that are uniquely enabled by these hybrid-tagging approaches.

Fluorogen activating protein toolset for protein trafficking measurements

“…The rapid and specific labeling of a tagged protein of interest (POI), intracellular or surface, with otherwise nonfluorescent green‐emitting “thiazole orange” or far‐red emitting “malachite green” and “dimethylindole red” dye derivatives creates a toolset suitable for scalable, dynamic multi‐color imaging experiments and direct quantitative trafficking‐related measurements, across many distinct fluorescent measurement platforms . Over the past several years, a library of distinct fluorogenic malachite green‐based ligands has been demonstrated to bind to a common, FAP tag, the dL5** FAP (eg, Addgene plasmid #73206) . These dyes include cell‐excluded and cell‐permeable fluorogens (Figures and ).…”

“…22 Over the past several years, a library of distinct fluorogenic malachite green-based ligands has been demonstrated to bind to a common, FAP tag, the dL5** FAP (eg, Addgene plasmid #73206). 5,7,19 These dyes include cell-excluded and cell-permeable fluorogens (Figures 2, 3 and 4). Recently another lab, Hu and colleagues, has started to develop several new malachite green derivatives.…”

Fluorescence imaging using synthetic GFP chromophores

“…In this mini-review we will describe only the applications of the synthetic FP Cros for fluorescence imaging, and some fluorescence studies in solutions which can be potentially applied for imaging. Indeed, numerous classes of various fluorogens are known [7][8][9] which are used for the fluorimetric determination of analytes described in this mini-review.…”

Quantitative techniques for imaging cells and tissues

“…These properties are not always found in the fluorescent proteins. Bruchez and his colleague (Yan and Bruchez, 2015) discuss the current state of the field of chemical labeling in biological tissues. Using chemical handles introduced to targets of interest in cells, chemical dyes can be introduced.…”