Figure 2.

Exo2 inhibits Cl⁻ secretion in T84 cells. (A) Short-circuit current (I_sc, mean±s.d.) in polarized T84 cells treated with CT alone (open circles), Exo2 alone (open squares), CT with Exo2 (solid squares), and CT with BFA (solid triangles). Forskolin was added at 140 min (Fsk, arrows). (B) Exo2 acts downstream of cAMP. T84 cells were pretreated with vehicle alone DMSO (circles), BFA (triangles) or Exo2 (squares), and I_sc (arrow) was induced with forskolin (filled symbols) or 8-Br-cAMP (open symbols). Averages of duplicates are shown. (C,D) Maximal Cl⁻ secretion responses induced by CT (C) or anthrax EF (D) in the presence or absence of forskolin.