During what process are lysosomal enzymes sorted to their destination?

The sorting of lysosomal enzymes to their appropriate destination occurs primarily in the trans-Golgi network. During this process, proteins destined for lysosomes undergo a critical modification where a mannose-6-phosphate (M6P) marker is added. This modification signals that these proteins need to be transported to lysosomes.

Once the lysosomal enzymes reach the trans-Golgi network, they are packed into vesicles that are specifically targeted to the lysosomes. The presence of the M6P marker allows the enzymes to be recognized by specific receptors in the membrane of the trans-Golgi network, ensuring that only the correctly modified proteins are directed toward the lysosomal compartments.

This sorting mechanism is distinct from other cellular processes such as post-translational modifications and endocytosis. Post-translational modifications generally refer to the various chemical changes that proteins can undergo after translation, which may include phosphorylation, glycosylation, or ubiquitination, but these modifications do not specifically address the sorting to lysosomes. Endocytosis involves the uptake of molecules into cells but is not directly related to the sorting of lysosomal enzymes. The term "trailing pathway recognition" is not a standard term associated with lysosomal enzyme sorting and might lead to confusion