FIGURE 4.

Basal PI-3′-phosphatase activity of Ci-VSPTEN0 at resting membrane potential. A, membrane association of the PI(3,4)P₂ probe TAPP1-PH-YFP in cells either coexpressing Ci-VSPTEN0 (n = 47 cells from nine independent experiments) or Ci-VSPTEN0 with the inactivating mutation C363S (n = 35 cells from 10 experiments) was imaged by TIRF microscopy. H₂O₂ (1 mm) was applied for 15 min, followed by application of DTT (5 mm) for 15 min as indicated. B, average time constants obtained from monoexponential fits to the signal recovery upon application of DTT from the same experiments shown in A. Error bars indicate S.E.