GEN-Click: Genetically Encodable Click Reactions for Spatially Restricted Metabolite Labeling

Abstract

GEN-Click is a genetically encoded copper-click reaction.It enables spatial biotin labeling of the azide or alkyne-tagged biomoleculesin live cells. Chemical reactions for the in situ modificationof biomolecules within living cells are under development. Among thesereactions, bio-orthogonal reactions such as click chemistry usingcopper(I) and Staudinger ligation are widely used for specific biomoleculetracking in live systems. However, currently available live cell copper(I)-catalyzedazide/alkyne cycloaddition reactions are not designed in a spatiallyresolved manner. Therefore, we developed the "GEN-Click"system, which can target the copper(I)-catalyzed azide/alkyne cycloadditionreaction catalysts proximal to the protein of interest and can begenetically expressed in a live cell. The genetically controlled,spatially restricted, metal-catalyzed biorthogonal reaction can beused for proximity biotin labeling of various azido-bearing biomolecules(e.g., protein, phospholipid, oligosaccharides) in living cell systems.Using GEN-Click, we successfully detected local metabolite-transferringevents at cell-cell contact sites.