Nanoscale Mapping of the Subcellular Glycosylation Landscape

Area of Science:

• Biochemistry
• Cell Biology
• Glycobiology

Background:

• Glycosylation is a vital post-translational modification creating diverse protein structures and functions.
• Aberrant glycosylation is linked to diseases such as cancer and neurodegenerative disorders.
• Intracellular and organelle-specific glycan organization remains poorly understood compared to cell surface glycans.

Purpose of the Study:

• To systematically map the nanoscale spatial arrangement of glycans within cellular organelles.
• To develop and apply a super-resolution imaging technique for visualizing intracellular glycosylation.
• To investigate glycan distribution in neuronal tissues and various cellular compartments.

Main Methods:

• Utilized super-resolution microscopy with fluorophore-labeled lectins.
• Developed and implemented a multiplexing strategy termed Glyco-STORM.
• Applied the technique to thin neuronal tissue sections and permeabilized cells.

Main Results:

• Visualized nanoscale nanodomains within the endoplasmic reticulum and subdomains in the Golgi apparatus.
• Characterized diverse glycosylation states across the endolysosomal system, including a polarized lysosomal clathrin coat.
• Mapped mature glycans at neuronal synapses, defining the synaptic cleft and subsynaptic tubules.

Conclusions:

• Glyco-STORM provides the first comprehensive nanoscale map of intracellular glycosylation.
• Revealed distinct glycosylation patterns across various organelles and cellular compartments.
• Offers a new tool for investigating the role of glycosylation in cellular processes and disease states.