Lysosomal Biogenesis and Degradation Pathways

In the trans-Golgi, M6P receptors (M6PRs) recognize these tagged proenzymes and sort them into clathrin-coated vesicles (CCVs) for transport to lysosomes. Upon arrival in the lysosome, the acidic environment removes the M6P tag, activating the hydrolases (1).

M6PRs also function in retrieving secreted or misrouted lysosomal enzymes, recycling between the Golgi and the plasma membrane (2). Lysosomes degrade cellular components via macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA). Macroautophagy delivers cargo through autophagosomes that fuse with lysosomes and lysosomes are regenerated from autolysosomal membranes (3).