Visualizing specific protein glycoforms bytransmembrane fluorescence resonanceenergy transfer

摘要

Analyses of mice lacking glycosyltransferase have suggested that their pathological phenotypesare not attributable to the overall change of the sugar modification, but instead the result ofchanges of the glycan structures on a specific ‘target’ glycoprotein. Therefore, detecting ormonitoring the glycosylation status of a specific protein in living cells is important, but nosuch methods are currently available. Here we demonstrate the detection of glycoforms ofa specific glycoprotein using the fluorescence resonance energy transfer technique. usingmodel proteins, we detect characteristic fluorescence resonance energy transfer signals fromthe specific glycoform-bearing target glycoprotein. We also show that, upon insulin removal,sialylated glycoforms of green fluorescent protein-tagged GLuT4 seem to be internalized moreslowly than non-sialylated GLuT4. This novel analytical imaging tool allows studying the rolesof specific glycan modifications of a protein of interest.