Fig. 3.

The lipid raft association of DRA and DRA-ETKFminus is sensitive to cholesterol depletion. Caco-2/BBE/EGFP-DRA (A) and Caco-2/BBE/EGFP-DRA-ETKFminus (B) cells were lysed with 1% Triton X-100 and subjected to density gradient centrifugation. Top: in untreated cells EGFP-DRA and EGFP-DRA-ETKFminus float to low-density lipid raft fractions as evidenced by their cosegregation with the raft marker flotillin. Bottom: treatment with 20 mM methyl-β-cyclodextrin (MCD) at 37°C for 60 min completely shifted both EGFP-DRA and EGFP-DRA-ETKFminus out of the low-density raft fractions, whereas flotillin was only incompletely shifted. Representative data of 4 experiments.