Epithelial Cell Lysosome Dynamics

Since lysosomes are considered the “digestion machines” of the cytoplasm, these organelles go to work when the cell absorbs nutrient materials. Once a nutrient cluster is inside the cell, the lysosomes attach and release their enzymes. The enzymes break down complex molecules that can include complex sugars and proteins. In cases in which food is scarce and the cell is starving, the lysosomes go to work even if there is no food for the cell. When the signal is sent out, lysosomes will actually digest the cell organelles for nutrients. In the digital videos presented above, normal opossum kidney epithelial cells (OK line) are imaged expressing enhanced green fluorescent protein (EGFP) fused to lysosomal associated membrane protein 1 (LAMP1), which targets the lysosomes.