Subcellular Distribution of Mouse Mevalonate Pyrophosphate Decarboxylase

Abstract

Mevalonate pyrophosphate decarboxylase (MPD) is considered to be a cytosolic protein. Recently, other groups reported that MPD is mostly located in the peroxisomes. In this study, we examined whether the expression of MPD in mice depends on the proliferation of peroxisomes, and whether MPD is predominantly located in the peroxisomes or the cytosol of mice. No increase in the protein level of MPD was observed in the crude extract of the livers of mice administered with peroxisome proliferative drugs. The result suggests that the expression of MPD is independent of the proliferation of peroxisomes, and may be maintained via a specific regulatory mechanism, different from the regulation of the expression of peroxisome proliferator-activated receptor alpha. When the subcellular distribution of MPD in mouse melanoma (B16F10) cells was examined by cell fractionation, MPD was detected in the cytosol of B16F10 cells, but not in the peroxisomes. In permeabilized B16F10 cells treated with digitonin, which lack cytosolic enzymes, 80% and 20% of MPD, 75% and 25% of lactate dehydrogenase, or 2% and 98% of catalase, existed in the medium and in the cell, respectively. From these results, it indicated that MPD was predominantly located in the cytosol and did not exist in the peroxisomes of B16F10 cells.

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

“…We previously reported that MPD is predominantly located in the cytosol of B16F10 without melanin; 13) however, no subcellular distribution of MPD in B16 containing a lot of melanin was found. In order to identify whether the subcellular distribution of MPD changed by differences in melanin biosynthesis, the subcellular distribution of MPD in B16 was examined using permeabilized cells, which retain their organelle integrity yet lack cytosolic components.…”

“…8) We previously reported that MPD was predominantly located in the cytosol of rat hepatocytes, 12) normal rat kidney cells (NRK), 12) or mouse melanoma cells (B16F10) 13) treated with fetal bovine serum (FBS), respectively, since in permeabilized rat hepatocytes, NRK, or B16F10 treated with digitonin, which lack cytosolic enzymes, MPD was mainly present in the medium (cytosolic fraction).…”

Tissue Distribution of Mevalonate Pyrophosphate Decarboxylase in Guinea Pig

“…Cell Fractionation Isolation of post-nuclear supernatant (PNS), mitochondria, peroxisome, lysosome (MPL), and microsomal and cytosol fractions from various guinea pig tissues by cell fractionation was carried out as described by Michihara et al 14) Tissues were homogenized with 3 volumes of homogenate buffer without Triton X-100. The homogenate was centrifuged at 1000ϫg for 10 min.…”

Comparison of the Gene Expression Levels of Mevalonate Pyrophosphate Decarboxylase between Stroke-prone Spontaneously Hhypertensive and Wistar Kyoto Rats

“…However, there is little information on the gene expression of MPD in rats, although analyses of the MPD protein have been performed. [6][7][8][9][10][11][12][13] Thus, we examined the distribution of the mRNA levels in Wistar rat tissues by real-time PCR, to clarify the relationship between protein and mRNA levels of MPD. Next, we compared the mRNA levels of MPD in liver and brain between SHRSP and normotensive WKY.…”