FIG. 7.

Bladder cells take up AOAH precursor. (A) Uptake of pro-AOAH by T24 cells after incubation with pro-AOAH-containing medium for 5 h in the presence or absence of 10 mM M6P, G6P, or mannose. Washed cells were lysed and AOAH protein was assayed by ELISA. Each bar shows the mean and standard error of data from four independent experiments. (B) AOAH specific activity (activity/nanograms of protein) in T24 cell lysates. Compared to the pro-AOAH added in the medium (AOAH Source), cell-associated AOAH had a much greater specific activity, reflecting its activation by the T24 cells. M6P inhibited AOAH binding (A) but did not prevent the activation of the cell-associated AOAH (B).