cDNA cloning and gene expression analysis of human myo-inositol 1-phosphate synthase.
myo-Inositol 1-phosphate synthase (EC 5.5.1.4) (IPS) is a key enzyme in myo-inositol biosynthesis pathway. This study describes the molecular cloning of the full length human myo-inositol 1-phosphate synthase (hIPS) cDNA, tissue distribution of its mRNA and characterizes its gene expression in cultured HepG2 cells. Human testis, ovary, heart, placenta, and pancreas express relatively high level of hIPS mRNA, while blood leukocyte, thymus, skeletal muscle, and colon express low or marginal amount of the mRNA. In the presence of glucose, hIPS mRNA level increases 2- to 4-fold in HepG2 cells. hIPS mRNA is also up-regulated 2- to 3-fold by 2.5 microM lovastain. This up-regulation is prevented by mevalonic acid, farnesol, and geranylgeraniol, suggesting a G-protein mediated signal transduction mechanism in the regulation of hIPS gene expression. hIPS mRNA expression is 50% suppressed by 10mM lithium ion in these cells. Neither 5mM myo-inositol nor the three hormones: estrogen, thyroid hormone, and insulin altered hIPS mRNA expression in these cells.
Guan
Guimin
G
Department of Surgery, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
Dai
Peihua
P
Shechter
Ishaiahu
I
D000595:Amino Acid Sequence; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular / Q000379:methods*; D019204:GTP-Binding Proteins / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008148:Lovastatin / Q000494:pharmacology; D008969:Molecular Sequence Data; D007296:Myo-Inositol-1-Phosphate Synthase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D009928:Organ Specificity; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment / Q000379:methods; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured / Q000201:enzymology
D012333:RNA, Messenger; D008148:Lovastatin; D019204:GTP-Binding Proteins; D007296:Myo-Inositol-1-Phosphate Synthase