NATIONAL SCIENCE FOUNDATION
U.S. DEPARTMENT OF EDUCATION
Protein Modification (Golgi): Advanced Look --> 2.) Endosome
Upon reaching the endosome, modification of the hydrolase enzymes continues. Clicking on each of the thumbnail images will bring up a larger, labeled version of the described scene.
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The transport vesicle from the trans-Golgi moves toward the endosome, which can eventually mature into a lysosome.
Once the vesicle docks and merges with the endosome, the M6P receptors release the hydrolase enzymes.
Inside the endosome, the phosphate portion of the M6P signal on the hydrolase enzyme is removed.
The hydrolase can then be activated and go on to break down other molecules in the lysosome.
The M6P receptors are then recycled back to the trans-Golgi within transport vesicles that bud off of the endosome.
The M6P signal is one of several sorting signals used to target proteins to different cellular locations.