Fig. 5.

Acetaldehyde increases association of PP2A with occludin. A: immunoprecipitates of occludin from Caco-2 cell monolayers exposed to acetaldehyde (400 μM) for varying times were assayed for PP2A phosphatase activity in the absence (gray bars) or presence (black bars) of fostriecin. Values are means ± SE (n = 4). *Significantly different from corresponding values for activities in the absence of fostriecin. B and C: occludin immunoprecipitates prepared from cells incubated with acetaldehyde for varying times were immunoblotted (IB) for PP2A-C (B), and the PP2A band densities in different experiments were evaluated (C). Values are means ± SE (n = 3). *Significantly different from corresponding values for 0-min control.