Fig. 3.

Epsin 3 colocalizes with clathrin at apical canaliculi of parietal cells in both resting (cimetidine) and stimulated (histamine) WT stomachs. Immunofluorescence of semithin sections. (A) H/K ATPase is localized outside the profiles of apical canaliculi (as defined by ezrin immunoreactivity) in a resting cell, but is present at the canaliculi in a stimulated cell. A white asterisk indicates the position of the nucleus. (B) Epsin 3 has a highly punctate localization at the cytoplasmic surface of canaliculi in both conditions. (C) Epsin 3 spots overlap with a subset of clathrin spots (Insets show regions enclosed by rectangles at higher magnification). The green fluorescence observed in some fields (black asterisks) is because of nonspecific fluorescence generated by secondary antibodies. (Scale bars, 10 μm.)