Osmotic stress enhances the lysosomal localization of myc-CLN3.

<p>BHK clone 19 myc-CLN3-expressing cells were grown on poly-D-lysine coated coverslips either under isotonic (300 mOsm) or hyperosmotic conditions. Osmolarity was increased at 100 mOsm intervals to 800 mOsm by the addition of NaCl/urea. After being exposed to 800 mOsm for 24 hours, cells were fixed, permeabilized and immunofluorescently stained for the myc-tag (to detect myc-CLN3; green) and for the lysosomal marker, LAMP1 (red). Under isotonic conditions, a portion of myc-CLN3 is localized to lysosomes. In the merged images yellow indicates the lysosomal localization of myc-CLN3. Myc-CLN3 distribution in lysosomes is enriched at 800 mOsm. The white-framed areas of the merged images are enlarged at the right side of the figure to highlight the osmotic stress-induced increase in the lysosomal localization of myc-CLN3. Arrows in the enlarged images taken from isotonic cultures point to myc-CLN3 localized in lysosomes. Images were taken with a confocal microscope. Scale bars indicate 10 µm.