Intracellular Dynamics of Lysosomes Following the Disruption of Lysosome Associated Membrane Proteins (LAMP)

The intracellular degradation of extracellular cargo is a process crucial to maintaining cellular health. In the classic model, degradation occurs inside the lysosome. However an alternative pathway has been proposed in which degradation occurs inside the late endosome, with the lysosome serving as an enzyme-storage vesicle. To test this new model, we have disrupted two key lysosomal proteins, LAMP1 and 2, in intact live cells using endoglycosidase H (Endo H). Following Endo H treatment, lysosome mobility was measured using live cell imaging and single particle tracking. Enzymatic activity was measured using fluorogenic substrates. We found that Endo H treatment alters the morphology and mobility of the lysosome and leads to alternate degradation pathways within the cell.