Figure 9. D₁R-GFP and SNX19 are expressed in lipid raft and non-raft domains.

A: The colocalization of D₁R-GFP with CAV-1 (lipid raft marker, arrows) and SNX19 with CAV-1 and, to a lesser degree, to CD71 (non-raft domain marker, arrows) is increased by fenoldopam (1 μM, 1 & 3 min). Images were obtained via laser confocal microscopy. 630x magnification, bar scale = 10 μm. B: Fenoldopam (D₁-like receptor agonist,1 μM) internalized and increased the colocalization of D₁R and SNX19 at 5 min & returned to 0 min position after 60 min in RPTCs. PM=plasma membrane. C: D₁R and SNX19 basally co-localized in RPTs of untreated mouse kidney (“vehicle”). Fenoldopam (2 μg/kg/min/5 min) increased the co-localization of D₁R and SNX19 in the cytosol of mouse RPTs. WGA= wheat germ agglutinin, plasma membrane marker. DAPI=nucleus. D: Colocalization of D₁R (pseudocolored green) and SNX19 (pseudocolored magenta) at the plasma membrane of renal proximal tubule of C57BL/6J mouse on normal salt diet (0.8% NaCl, 7 days) is denoted by the white circumscribed areas. The composite image was obtained via STED microscopy