Trafficking of lysosomal enzymes in normal and disease states

The targeting of newly synthesized lysosomal enzymes to lysosomes involves a series of discrete steps, each mediated by a specific signal. Some of these signals are protein in nature while others are carbohydrate. The early steps in targeting are shared with proteins destined for secretory granules or the plasma membrane. A number of patients with lysosomal storage disorders have mutations which result in the malfunction of this targeting pathway.