(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 3. Expression of CD9 redistributes TGF
to the apical site in polarized epithelial cells. MDCK cells that express CD9, TGF
or both proteins were grown in Transwell chambers to allow them to fully establish their polarized phenotype. (A) Cells were fixed and stained for CD9 or TGF
, and immunofluorescence was visualized by confocal microscopy (xz section). (B) Expression of CD9 does not alter the distribution of transmembrane TGF
that lacks the TGF
core sequence in polarized epithelial cells. MDCK cells stably expressing CD9, TGF
E or both were grown in Transwell chambers to establish a polarized phenotype. Cells were fixed, stained for CD9 or TGF
E, and immunofluorescence was visualized by confocal microscopy (xz section). (C) Cells were subjected to biotinylation of cell-surface proteins in the apical or basolateral compartments, and cell-surface TGF
and CD9 were visualized by immunoblotting. Arrow indicates the position of TGF
form III. (D) Same experiment as in C, but visualizing the biotinylated E-cadherin or p58, two proteins that are largely expressed in the basolateral compartment, and the apical marker gp135.