Fig. 4. Expression of the µ1B subunit in melanocytic cells. (A) µ1B transcript levels determined by semi-quantitative real-time PCR. Note the expression of µ1B in NHEK was significantly higher than in melanocytic cells (^*). (B) Melanoma cells as noted were pulse-labeled for 30 minutes, and extracts were immunoprecipitated under denatured and reduced conditions with an anti-µ1B antibody or with normal rabbit serum as a control. Immune complexes were denatured and reduced before separation on gels and visualization by fluorography. (C-H) Cells were fixed 48 hours after transfection with µ1B-HA, and stained with a combination of PEP13h (red) and anti-HA (green) antibodies (arrows indicate complexes). Specimens were analyzed by confocal microscopy. Nuclei were counterstained with DAPI (blue). Representative images are shown. Bars, 10 µm (C,F); 1 µm (D,E,G,H).