Figure 5.

Immunofluorescence staining of PC in transfected CHO-K1 and MDCK cells. (a) In nonpolarized CHO-PC13 cells stably expressing PC, PC is distributed diffusely over the entire cell surface. (b and c) In MDCK-PC8 cells, PC is expressed in a punctate pattern on the apical surface (above the level of the TJ) as seen in both en face (b) and in X-Z cross-sections (c) taken in 0.1-μm steps through the cells. Thus, PC is correctly targeted to the apical plasma membrane in MDCK cells, which is equivalent to its location in the glomerular epithelium. Cells were grown on glass coverslips, fixed in paraformaldehyde, permeabilized, and immunostained with anti-PC mAb 5A as described in MATERIALS AND METHODS. Bars, 10 μm.