Difference in Subcellular Distribution of Mevalonate Pyrophosphate Decarboxylase Occurs by Cell Type

Recently, it has been questioned whether mevalonate pyrophosphate decarboxylase (MPD) is predominantly located in the peroxisomes or cytosol. We previously reported that MPD was predominantly present in the cytosol of rat hepatocytes, normal rat kidney cells, or mouse melanoma cells. In the present study, we examined whether MPD was predominantly present in the cytosol of HepG2 (human hepatoma) cells and Cos7 (monkey kidney) cells using digitonin permeabilization. In HepG2 cells permeabilized with digitonin, 90%and 10%of MPD existed in the cytosol and membrane/organelle (M/O) fraction, respectively, while in Cos7 cells permeabilized with digitonin, 20% and 80% of MPD existed in the cytosol and M/O fraction, respectively. These data suggest that the difference in subcellular distribution of MPD is due to the cell type.