Figure 6. Transient glucose removal leads to a reversible change in the ATP/ADP signal.
(a) A cultured HEK293 cell expressing Perceval and loaded with the pH sensitive dye SNARF-5F displays an alkalinization when glucose is removed from the extracellular solution (10 mM glucose was replaced by equimolar sucrose). The Perceval signal shows a slight decrease upon glucose wash-out and a prominent rebound upon glucose wash-in. (b) The pH-corrected Perceval signal reveals a gradual decrease in cellular energy that is reversed rapidly upon glucose reapplication. Perceval occupancy of 0 corresponds to ADP ≫ ATP; occupancy of 1 corresponds to ATP ≫ ADP.