Fig. 7. Association of wild-type and claudin-14 with DRMs. MDCK cells were induced to express either wild-type (left) or mutant (right) claudin-14. DRMs were prepared as described and fractions of sucrose gradients were electrophoresed, transferred to nitrocellulose and immunoblotted as previously described. Caveolin (A,B, top) was used an indicator of for DRMs and was concentrated at the 5-38% interface (fraction 2). Wild-type claudin-14 was concentrated in the same fraction, whereas the 4S mutant was found equally at this interface and throughout the rest of the gradient (A,B, bottom). B represents quantification (white bars, caveolin and claudin-14 from cells expressing wild-type claudin-14; black bars, caveolin and claudin-14 from cells expressing 4S mutant) of the immunoblot shown in A; replicate experiments gave similar results.