To clarify the metabolic bases of characteristic increases in the concentrations of glucosylceramide (CMH) and GM3 in peroxisome-defective mutant Chinese hamster ovary (CHO) cells (Z65), we measured the ceramide glucosyltransferase (CGT) and beta-glucosidase activities in Z65 and CHO-K1 cells, and found that the former enzyme was responsible for the accumulation of CMH in Z65 cells. Inhibition of CGT by D,L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) caused a marked reduction in a incorporation of [3-14C]serine to CMH in both CHO-K1 and Z65 cells, but resulted in the accumulation of ceramide in Z65 cells in a concentration higher than that in CHO-K1 cells. Then, we cloned the cDNA encoding CGT from CHO-K1 cells, which exhibited sequence homology with the human gene product (98.7%). Northern blot analysis of CGT revealed increased expression of it in Z65 cells compared with that in CHO-K1 cells, which probably caused the simultaneous increase in GM3. With an immunohistochemical procedure, GM3 was found to be more strongly expressed in the cell membrane of Z65 cells than in CHO-K1 cells.
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http://dx.doi.org/10.1016/s0003-9861(02)00216-3 | DOI Listing |
Int J Biol Macromol
May 2019
Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, No. 159, Baojian Road, Nangang District, Harbin, Heilongjiang 150080, China. Electronic address:
Glioma is a kind of malignant brain tumor which damages the central nervous system of adults. Recent years, the molecular mechanism involved in the initiation and progression of glioma has been widely reported. Long non-coding RNAs (lncRNAs) have been proved to be significant modulators in the biological processes of glioma.
View Article and Find Full Text PDFBiochim Biophys Acta
May 2009
Department of Biology, Faculty of Sciences, Graduate School of Systems Life Sciences, Kyushu University Graduate School, Fukuoka 812-8581, Japan.
Pex7p, the peroxisome-targeting signal type 2 (PTS2) receptor, transports PTS2 proteins to peroxisomes from the cytosol. We here established a cell-free Pex7p translocation system. In assays using post-nuclear supernatant fractions each from wild-type CHO-K1 and pex7 ZPG207 cells, 35S-labeled Pex7p was imported into peroxisomes.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
June 2007
Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Changes in the molecular species of lipids associated with Pex2 gene-mutation were investigated to elucidate the pathogeneses of peroxisome biogenesis disorders. Although no differences were observed in the concentrations of cholesterol and phosphatidyl choline between mutated Z65 and control CHO-K1 cells, the amounts of cholesterol esters and glycolipids in Z65 cells were twice those in CHO-K1 cells, but phosphatidyl ethanolamine (PE), particularly 1-O-octadec-1'-enyl-2-oleoyl PE, was absent in Z65 cells by FABMS. Enhanced synthesis of glycolipids in Z65 cells was associated with an abundance of lignoceric acid-containing ones, suggesting a role of glycolipids in the retention of longer saturated fatty acids.
View Article and Find Full Text PDFArch Biochem Biophys
July 2002
Department of Pediatrics, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
To clarify the metabolic bases of characteristic increases in the concentrations of glucosylceramide (CMH) and GM3 in peroxisome-defective mutant Chinese hamster ovary (CHO) cells (Z65), we measured the ceramide glucosyltransferase (CGT) and beta-glucosidase activities in Z65 and CHO-K1 cells, and found that the former enzyme was responsible for the accumulation of CMH in Z65 cells. Inhibition of CGT by D,L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) caused a marked reduction in a incorporation of [3-14C]serine to CMH in both CHO-K1 and Z65 cells, but resulted in the accumulation of ceramide in Z65 cells in a concentration higher than that in CHO-K1 cells. Then, we cloned the cDNA encoding CGT from CHO-K1 cells, which exhibited sequence homology with the human gene product (98.
View Article and Find Full Text PDFCell Biochem Biophys
June 2001
Department of Biology, Graduate School of Science, Kyushu University, Fukuoka 812-8581, Japan.
Peroxisome assembly in mammals requires more than 14 genes. So far, we have isolated seven complementation groups (CGs) of peroxisome biogenesis-defective Chinese hamster ovary (CHO) cell mutants, Z65, Z24/ZP107, ZP92, ZP105/ZP139, ZP109, ZP110, ZP114. Two peroxin cDNAs, PEX2 and PEX6, were first cloned by genetic phenotype-complementation assay using Z65 and ZP92, respectively, and were shown to be responsible for peroxisome biogenesis disorders (PBD) such as Zellweger syndrome, of CG-F (the same as CG-X in U.
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