Amplified Visualization of Protein-Specific Glycosylation in Zebrafish via Proximity-Induced Hybridization Chain Reaction.

The visualization of glycosylation states of specific proteins in vivo is of great importance for uncovering their roles in disease development. However, the ubiquity of glycosylation makes probing the glycans on a certain protein as difficult as looking for a needle in a haystack. Herein, we demonstrate a proximity-induced hybridization chain reaction (HCR) strategy for amplified visualization of protein-specific glycosylation. The strategy relies on designing two kinds of DNA probes, glycan conversion probes and protein recognition probes, which are attached to glycans and target proteins, respectively. Upon sequential binding to the targets, the proximity-induced hybridization between two probes occurs, which leads to the structure-switching of protein recognition probes, followed by triggering of HCR assembly. This strategy has been used to visualize tyrosine-protein kinase 7-specific sialic acid in living CEM cells and zebrafish and to monitor its variation during drug treatment. It provides a potential tool for investigating protein-specific glycosylation and researching the relation between dynamic glycans state and disease process.