FIGURE 6.

NHERF3 and NHE3 colocalize in BB of Caco-2BBe cells under basal conditions and dissociate after 10 μm carbachol treatment. Caco-2BBe cells were grown on Anapore filters until they reached 12 days post-confluence. Cells were then infected with adenovirus containing the 3HA-tagged NHE3 construct. On day 14, cells were fixed with 3% paraformaldehyde, permeabilized, and stained with antibodies to NHE3 and NHERF3 and localization determined by confocal microscopy. A, in the BB of Caco-2BBe cells, NHE3 and NHERF3 colocalize under basal conditions. B, after treatment with carbachol (10 min), NHERF3 expression becomes clustered within the BB and no longer colocalizes with NHE3. NHE3 also appears to move to a subapical region after carbachol treatment. Similar results were obtained from three individual experiments.