Which of the following features of the carbohydrate portion of glycoproteins determines their uptake into lysosomes?
A) multiple galactose residues
B) N-acetylneuraminic acid residues
C) O-linked oligosaccharides
D) terminal fucose residues
E) terminal mannose 6-phosphate residues

Question

Quizplus · Accepted Answer

The presence of terminal mannose 6-phosphate residues on glycoproteins is recognized by mannose 6-phosphate receptors, which target them for transport to lysosomes.  Enzymes that are destined for the lysosomes (lysosomal enzymes) are directed there by a specific carbohydrate modification. During transit through the Golgi apparatus, a residue of GlcNAc-1-phosphate (GlcNAc-1-P) is added to the carbon-6 hydroxyl group of 1 or more specific mannose residues that have been added to these enzymes. A specific Man-6-P receptor (MPR) is present in the membranes of the Golgi apparatus. Binding of Man-6-P to this receptor targets proteins to the lysosomes.

Which of the Following Features of the Carbohydrate Portion of Glycoproteins