Figure 1.

Kinetic analysis of ¹⁴C-Suc uptake by transgenic yeast cells. A, Uptake of Suc into yeast cells transformed with AmSUT1 in sense orientation (yeast strain CKY-Am1s; •) and Suc uptake into control cells transformed with AmSUT1 in antisense orientation (yeast strain CKY-Am1as; □). Transport assays were performed with an initial outside Suc concentration of 1 mm at pH 5.5. B, pH dependence of Suc uptake by yeast cells expressing AmSUT1 (yeast strain CKY-Am1s). C, Lineweaver-Burk plot of Suc uptake as a function of concentration in yeast cells expressing AmSUT1 (yeast strain CKY-Am1s). Reciprocal uptake rates are plotted against reciprocal Suc concentrations in the assays.