Exogenous heparan sulfate influences subcellular localisation of caveolin-2. (A) Detergent-resistant membrane (DRM) preparations were made from MDA-MB231 lysates, some treated with 20 μg/ml heparan sulfate for 24 h. Nine fractions were collected from each centrifuge tube and western blotted for flotillin as a marker of DRM pools, transferrin receptor as a marker of detergent soluble membrane proteins (non-DRM), and caveolin-2. The caveolin-2 is almost exclusively in the DRM pool of control cells, while it is displaced to the non-DRM pool when cells are treated with heparan sulfate. Syndecan-2 is reduced after heparan sulfate treatment (B) Caveolin-2 staining of untreated (Ctrl) MDA-MB231 cells and cells treated with 20 μg/ml heparan sulfate (HS) for 24 h before fixation. While the HS-treated cells are more spread than control cells, there is no obvious alteration in the localisation of caveolin-2. Bar = 25 μm.