Fig. 4.

Both caveolae and clathrin pathways are involved in UT-A1 endocytosis. A: knockdown of dynamin, μ2, or caveolin-1 by RNA interference increases UT-A1 membrane expression. UT-A1-HEK293 cells were transfected with pSuppressor/scramble, dynamin, AP-2 μ2, or caveolin-1 for 48 h. Cells were processed for biotinylation. Total cell lysate and biotinylated samples were blotted with the corresponding antibodies. B: inhibition of the caveolae or clathrin pathway causes UT-A1 cell membrane accumulation. UT-A1-HEK293 cells were treated with 5 mM methyl-β-cyclodextrin (MβCD) or 250 μg/ml concanavalin A (ConA) or MβCD + ConA for 1 h; cells were then processed for biotinylation assay. The biotinylated samples were blotted for UT-A1.