Related Experiment Video
Updated: Aug 18, 2026

Pulse-chase Analysis of N-linked Sugar Chains from Glycoproteins in Mammalian Cells
Published on: April 27, 2010
Oligosaccharide transport: pumping waste from the ER into lysosomes
1INSERM U504, Bâtiment INSERM, 16 Avenue Paul Vaillant-Couturier, 94807 Villejuif, France. u504@vjf.inserm.fr
Abstract:
N-glycans play important roles during the folding and secretion of glycoproteins. Surprisingly, during the N-glycosylation of glycoproteins, considerable amounts of unconjugated polymannose-type oligosaccharides ('free OS') are generated. Although free oligosaccharides have no known function in mammalian cells, a sophisticated cellular machinery enables them to be cleared from the endoplasmic reticulum (ER) into the cytosol and then re-enter the endomembrane system at the level of the lysosome. One possible function of this pathway is to stop free OS from interfering with the carbohydrate-dependent aspects of glycoprotein folding and transport along the secretory pathway.
Related Concept Videos
Recycling Endosomes and Transcytosis
The recycling endosome is not a single organelle but an extensively tubulated network of recycling pathways. It functions in storing molecules or transporting them across...
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Lysosomes
Delivery Pathways to the Lysosome
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
Lysosomal Hydrolases
Export of Misfolded Proteins out of the ER

