MoBio Transport to Lysosome Chapter 5

Glycosylated proteins in the Golgi apparatus will be delivered to lysosome if one or more mannose residues are phosphorylated on carbon atom 6. The trans-Golgi reticulum contains mannose 6-phosphate receptor which can bind to the phosphorylated mannose on lysosomal enzymes, directing the incorporation of the enzymes into transport vesicles.

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Figure 5-D-5. Structure of cathepsin D (a lysosomal enzyme) and the attached sugar molecules (including mannose). PDB ID = 1LYA.