Figure 2.

The E218Q mutant of basigin, but not the E218R mutant, supports lactate transport by MCT1 in Xenopus oocytes. In panel A, oocytes were injected with water (0), or cRNA for MCT1 (1) in the absence or presence (A) of antisense cRNA against Xenopus basigin and cRNA for rat basigin (B). Western blots are shown for the crude plasma membrane fraction using both MCT1 and basigin antibodies. In panel B rates of L-lactate (30 mM) transport into oocytes measured using BCECF fluorescence are shown as means±SEM of 5–8 separate oocytes. Where indicated, antisense (AS) against Xenopus basigin as well as the cRNA for WT-, E218Q- or E218R-basigin was co-injected with the MCT1 cRNA.