Abstract
The mechanism of inhibition of phosphatidylcholine (PC) biosynthesis by the isoprenoid farnesol was investigated in the human leukaemic CEM-C1 cell line. Cells were preincubated with 20 microM farnesol for up to 2 h and pulsed with [3H]choline. PC biosynthesis was inhibited to one-quarter at the step catalysed by cholinephosphotransferase (CPT). CPT activity in cellular homogenates from farnesol-treated cells was significantly decreased, but no changes in cytidylyltransferase activity or diacylglycerol concentration were observed. Measurements of CPT activity in the experiments in which farnesol was added directly to the homogenates or microsomal fractions demonstrated that farnesol did not affect CPT activity. However, cytosol from farnesol-treated samples decreased microsomal CPT activity almost twice as much as did cytosol from controls. This effect was found to be heat-stable, and disappeared after dialysis, but could not be attributed to farnesol present in the cytosol. The effect of farnesol was specific when compared with other structurally similar isoprenoids. We conclude that farnesol brings about changes in cultured cells, leading to decreased CPT activity, and thus to the inhibition of PC biosynthesis.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- BARTLETT G. R. Phosphorus assay in column chromatography. J Biol Chem. 1959 Mar;234(3):466–468. [PubMed] [Google Scholar]
- BLIGH E. G., DYER W. J. A rapid method of total lipid extraction and purification. Can J Biochem Physiol. 1959 Aug;37(8):911–917. doi: 10.1139/o59-099. [DOI] [PubMed] [Google Scholar]
- Das N. P., Allen C. M. Inhibition of farnesyl transferases from malignant and non-malignant cultured human lymphocytes by prenyl substrate analogues. Biochem Biophys Res Commun. 1991 Dec 16;181(2):729–735. doi: 10.1016/0006-291x(91)91251-7. [DOI] [PubMed] [Google Scholar]
- Geilen C. C., Wieder T., Reutter W. Hexadecylphosphocholine inhibits translocation of CTP:choline-phosphate cytidylyltransferase in Madin-Darby canine kidney cells. J Biol Chem. 1992 Apr 5;267(10):6719–6724. [PubMed] [Google Scholar]
- Hatch G. M., Jamil H., Utal A. K., Vance D. E. On the mechanism of the okadaic acid-induced inhibition of phosphatidylcholine biosynthesis in isolated rat hepatocytes. J Biol Chem. 1992 Aug 5;267(22):15751–15758. [PubMed] [Google Scholar]
- KENNEDY E. P., WEISS S. B. The function of cytidine coenzymes in the biosynthesis of phospholipides. J Biol Chem. 1956 Sep;222(1):193–214. [PubMed] [Google Scholar]
- Kent C. Regulation of phosphatidylcholine biosynthesis. Prog Lipid Res. 1990;29(2):87–105. doi: 10.1016/0163-7827(90)90010-i. [DOI] [PubMed] [Google Scholar]
- Kolesnick R. N., Hemer M. R. Physiologic 1,2-diacylglycerol levels induce protein kinase C-independent translocation of a regulatory enzyme. J Biol Chem. 1990 Jul 5;265(19):10900–10904. [PubMed] [Google Scholar]
- Maltese W. A. Posttranslational modification of proteins by isoprenoids in mammalian cells. FASEB J. 1990 Dec;4(15):3319–3328. doi: 10.1096/fasebj.4.15.2123808. [DOI] [PubMed] [Google Scholar]
- Melnykovych G., Bansal N., Houle A., Nyquist D., Musille V. Effects of compound RU38486 on growth and lipid biosynthesis in glucocorticoid sensitive human leukemia line CEM-C7. Ukr Biokhim Zh (1978) 1992 Mar-Apr;64(2):49–55. [PubMed] [Google Scholar]
- Melnykovych G., Haug J. S., Goldner C. M. Growth inhibition of leukemia cell line CEM-C1 by farnesol: effects of phosphatidylcholine and diacylglycerol. Biochem Biophys Res Commun. 1992 Jul 15;186(1):543–548. doi: 10.1016/s0006-291x(05)80842-3. [DOI] [PubMed] [Google Scholar]
- Melnykovych G., Standaert M. M., Matthews E. R., Gray S. L. Corticosteroids and phosphatidylcholine biosynthesis in microsomal fractions from L5178Y lymphoma. Cancer Res. 1976 May;36(5):1545–1550. [PubMed] [Google Scholar]
- O K. M., Choy P. C. Effects of fasting on phosphatidylcholine biosynthesis in hamster liver: regulation of cholinephosphotransferase activity by endogenous argininosuccinate. Biochem J. 1993 Feb 1;289(Pt 3):727–733. doi: 10.1042/bj2890727. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pelech S. L., Paddon H. B., Vance D. E. Phorbol esters stimulate phosphatidylcholine biosynthesis by translocation of CTP:phosphocholine cytidylyltransferase from cytosol to microsomes. Biochim Biophys Acta. 1984 Oct 4;795(3):447–451. doi: 10.1016/0005-2760(84)90171-1. [DOI] [PubMed] [Google Scholar]
- Pontoni G., Manna C., Salluzzo A., del Piano L., Galletti P., De Rosa M., Zappia V. Studies on enzyme-substrate interactions of cholinephosphotransferase from rat liver. Biochim Biophys Acta. 1985 Sep 11;836(2):222–232. doi: 10.1016/0005-2760(85)90070-0. [DOI] [PubMed] [Google Scholar]
- Schroepfer G. J., Jr Sterol biosynthesis. Annu Rev Biochem. 1981;50:585–621. doi: 10.1146/annurev.bi.50.070181.003101. [DOI] [PubMed] [Google Scholar]
- Sleight R., Kent C. Regulation of phosphatidylcholine biosynthesis in cultured chick embryonic muscle treated with phospholipase C. J Biol Chem. 1980 Nov 25;255(22):10644–10650. [PubMed] [Google Scholar]
- Tercé F., Record M., Ribbes G., Chap H., Douste-Blazy L. Intracellular processing of cytidylyltransferase in Krebs II cells during stimulation of phosphatidylcholine synthesis. Evidence that a plasma membrane modification promotes enzyme translocation specifically to the endoplasmic reticulum. J Biol Chem. 1988 Mar 5;263(7):3142–3149. [PubMed] [Google Scholar]