Fig. 4.

HK-2 cells silenced for CTNS gene show a reduction of enzymatic activities and subunit expression levels of the complexes I and V. Cysteamine restores the activities and protein expression. Human kidney-2 cells (HK-2) were transfected with siGENOME human CTNS gene (siCTNS) or non-targeting siRNA (Mock). Where indicated, the cells were treated for 24 h with DMSO (vehicle) or 100 µM cysteamine (MEA). a Proteins of cellular lysate were loaded on 8% SDS-PAGE, transferred to nitrocellulose membranes, and immunoblotted with the antibodies described in the figure. Protein loading was assessed by reprobing the blots with the actin antibody. The histograms represent the means values ± SEM of the ratio of ADU (arbitrary densitometric units) of the immune-revealed protein normalized on actin level (Student’s t test). b Enzymatic activities of complex I (NADH:ubiquinone oxidoreductase) and complex V (ATP hydrolase) were performed as described under “Methods”