FIGURE 5.
Basal ATPase activity of wild-type CTS and K478A mutant. Peroxisomes were isolated from oleate-grown wild-type BSL1-11B or pxa1Δ mutant yeast (PXA1KO), transformed with vectors encoding CTS, CTSK487A, or lacking an insert (control). A, ATPase activity was measured in the absence (black bars) or presence (open bars) of 10 mm AlFx. All samples were analyzed in triplicate, and the experiment was repeated three times. The data were used to compute the means and the mean ± S.E. The plot shows mean ± 95% confidence limit (computed from S.E. for n = 9) as indicated by the error bars. Data were analyzed by two-way analysis of variance, which indicated significantly higher ATPase activity of wild-type CTS compared with the K487A mutant (p < 0.05). The difference in the ATPase activity between the control BSL1–11B and the control pxa1Δ mutant was insignificant. B, total, cytosol, peroxisome, and mitochondria fractions were isolated from oleate-grown BSL1-11B cells (upper panel) or pxa1Δ cells (lower panel), transformed with the indicated constructs. Proteins (30 μg/lane) were separated by SDS-PAGE and immunoblotted with a CTS-specific antibody.