Figure 3.

In vitro functional characterization of sKlotho produced in mammalian cells. A, sKlotho is active in the FGF23 ERK1/2 activation assay. Purified sKlotho proteins were measured in the ERK1/2 activation assay as described under “Experimental procedures.” The error bars at each data point were calculated from three independent experiments. B, sKlotho possessed weak β-glucuronidase activity. Purified sKlotho proteins were measured in the β-glucuronidase assay as described under “Experimental procedures.” The error bars at each data point were calculated from four independent experiments. Data are shown as mean ± S.E. *, p < 0.05 versus HEK sKlotho, ANOVA.