Mevalonate Pyrophosphate Decarboxylase is Predominantly Located in the Cytosol of both B16 and B16F10 Cells in Mouse Melanoma Treated with Lovastatin

Recently, it has been questioned whether mevalonate pyrophosphate decarboxylase (MPD) is predominantly located in the peroxisomes or cytosol. We previously reported that a small amount of MPD in the liver of rats fed a CP diet (5% cholestyramine and 0.1% pravastatin) existed in the peroxisomes, although MPD is predominantly located in the cytosol in the liver of rats fed normal chow and a CP diet for 12 days. In the present study, we examined the subcellular distribution of MPD in mouse melanoma cells (B16 and B16F10) treated with or without lovastatin, using digitonin permeabilization and immunoblotting. In permeabilized B16 by digitonin after treatment with or without lovastatin, 95% and 5%, or 98% and 2% of MPD existed in the cytosol and membrane/organelle (M/O) fraction, respectively. Using B16F10 under the same conditions, 80% and 20%, or 91% and 9% of MPD existed in the cytosol and M/O fraction, respectively. These results indicated that MPD was predominantly located in the cytosol in both mouse melanoma cells treated with or without lovastatin.