PDE3B is present in caveolae-enriched fractions of hepatocyte plasma membranes.

<p>Plasma membranes isolated from mouse hepatocytes (50–120×10⁶) were sonicated in NaCO₃ and subjected to sucrose gradient fractionation as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0004671#s2" target="_blank">Materials and Methods</a>. Fractions of 0.8 ml were collected starting from the top. The fractions were analyzed for PDE3 activity and cholesterol (a), proteins (b) and subjected to immunoblot analysis (90 µl of each fraction) using antibodies against PDE3B, caveolin-1 (Cav-1) and flotillin-1 (Flot-1) (c). One representative experiment is shown (n = 4).