FIG. 3.

Efflux of Na⁺ from cells of wild type (wt), VK1, VK1/mrpA, VKN1, and VKN1/mrpA. The cells were washed, energy depleted, and loaded with 5 mM ²²NaCl as described in Materials and Methods. Efflux was initiated by diluting the suspension 100-fold into buffer (containing 5 mM NaCl) and no further additions (○), buffer containing 10 mM glucose (●), buffer containing glucose plus 10 mM cyanide (▵), or buffer containing glucose plus 10 μM CCCP (▴). Samples were taken at various times, filtered, and washed, and the radioactivity was determined by liquid scintillation counting.