Figure 3: Localization of tyrosine-phosphorylated proteins and
vinculin in the renal arterial endothelial cells. En face
preparations were stained with antiphosphotyrosine antibody
(PY-20) (a–c) or antivinculin antibody (d–f) and observed by
confocal laser scanning microscopy. The focal plane was adjusted
to the surface (a and d), middle (b and e), or basal (c and f)
portion of the endothelial cells. Tyrosine-phosphorylated
proteins were observed along the apical plasma membrane in
uniform staining (a). Strong staining for tyrosine-
phosphorylated proteins was detected at sites of cell-to-cell
apposition (b), with faint staining in the cytoplasm (c).
Antivinculin staining was detected at sites of cell-to-cell
apposition (e) and focal adhesion in the basal portion of the
cells (f: arrowheads). No staining for vinculin was detected at
the apical surface of the cells (d). The arrow indicates the
direction of blood flow. Bar: 50 μm.