(A) Activation of high affinity Cl⁻ transport in yhl008c strain compared with other deletant strains. Cells were grown in APG containing 40 mM NaCl as in Fig. 5 A, washed in cold LCAPG, and resuspended at t = 0 in LCAPG, pH 4.5, 30°C. At the indicated times, 8 μM Na³⁶Cl was added and the tracer influx measured for 1 min. Deletant strains are trk1 (○), trk2 (▿), gef1 (⋄), ypr003c (▵), bor1 (□), and yhl008c (•). The dotted line represents the sul1 data in Fig. 5 A. (B) High affinity Cl⁻ flux in strains yhl008c (•) and gef1 (⋄) after overnight growth in low Cl⁻ medium. Cells were prepared and initial influx was measured at pH 4.0 as a function of extracellular Cl⁻, as in Fig. 3 A. For comparison, the dotted curve represents the data from Fig. 3 A for control strain sul1.