FIGURE 4.

PI(4,5)P₂, PI(3,4,5)P₃, and NHE1 co-localize to lateral membrane domains. LLC-PK1 cells were polarized on permeable supports and transiently transfected with GFP-tagged PLCδ (A–C and G–J) or Akt (D–F and K–N) PH domain peptide cDNAs. NHE1 distribution was determined immunocytochemically with anti-NHE1, followed by Texas Red-conjugated anti-rabbit IgG (B, E, H, and L). Apical-basolateral junctions were labeled with ZO-1 antibodies, followed by AF488-conjugated goat anti-rat IgG (I and M, demarcated with arrowheads for clarity). Phosphoinositide, NHE1, and ZO-1 localization were detected in paraformaldehyde-fixed cells by confocal microscopy, and displayed in the X-Y (A–F) and X-Z plane (G–N).