Advertisement

Studies on the regulation of the biosynthesis of glucose-containing oligosaccharide-lipids. Effect of energy deprivation.

Open AccessPublished:August 10, 1983DOI:https://doi.org/10.1016/S0021-9258(17)44691-6
      This paper is only available as a PDF. To read, Please Download here.
      Energy deprivation, induced in thyroid slices by incubation with an uncoupler of oxidative phosphorylation (carbonyl cyanide m-chlorophenylhydrazone) or inhibitors of respiration (N2 or antimycin A), led to a disturbance in oligosaccharide-lipid metabolism which was characterized by a pronounced depletion of the glucosylated (Glc3Man9GlcNAc2) dolichyl pyrophosphoryl saccharide with an attendant accumulation of the Man9GlcNAc2 and, to a lesser extent, the Man8GlcNAc2 lipid-linked species. A concomitant decrease in the N-glycosylation of proteins was furthermore observed. The distribution of lipid-derived oligosaccharides observed by thin layer chromatographic separation was similar whether radiolabeling was achieved by a metabolic ([14C]glucose or [2-3H]mannose incubation) or chemical ([3H]NaBH4) procedure. The latter method proved useful for measuring the levels of individual oligosaccharide-lipids in unincubated tissue, and in this way it was found that unless thyroid was rapidly frozen or immediately immersed in oxygenated medium a marked decrease of glucose-containing oligosaccharide-lipids occurred which could, however, be reversed by a short incubation. The addition of glucose to the slice incubations did not prevent the Man8-9GlcNAc2 accumulation brought about by the inhibitors of energy production, nor did it alter the oligosaccharide-lipid pattern of uninhibited slices. The effect of the inhibitors on metabolically labeled liver slices was similar to that observed in thyroid. The size of the total chloroform/methanol/water (10:10:3)-extractable oligosaccharide-lipid pool (Glc3-Man9GlcNAc2 to Man5GlcNAc2) of thyroid remained quite constant (about 2 nmol/g) regardless of the energy state, and no substantial change in the level of smaller oligosaccharide-lipids, primarily represented by Man2GlcNAc2 (0.5 nmol/g) was evident. Moreover, no change in the total pool sizes was observed in puromycin-treated slices. The possible mechanisms by which energy deprivation leads to an accumulation of the glucose-free oligosaccharide-lipids are evaluated. While it is likely that a selective impairment of glucosylation of newly formed molecules occurs, it is also possible that an imbalance occurs in a postulated glucosyltransferase-glucosidase shuttle with a trapping of the oligosaccharide-lipid in its unglucosylated form.

      REFERENCES

        • Hubbard S.C.
        • Ivatt R.J.
        Annu. Rev. Biochem. 1981; 50: 555-583
        • Turco S.J.
        • Robbins P.W.
        J. Biol. Chem. 1979; 254: 4560-4567
        • Murphy L.A.
        • Spiro R.G.
        J. Biol. Chem. 1981; 256: 7487-7494
        • Spiro M.J.
        • Spiro R.G.
        • Bhoyroo V.D.
        J. Biol. Chem. 1976; 251: 6400-6408
        • Folch J.
        • Lees M.
        • Sloane Stanley G.H.
        J. Biol. Chem. 1957; 226: 497-509
        • Spiro R.G.
        • Spiro M.J.
        • Bhoyroo V.D.
        J. Biol. Chem. 1976; 251: 6409-6419
        • Godelaine D.
        • Spiro M.J.
        • Spiro R.G.
        J. Biol. Chem. 1981; 256: 10161-10168
        • Spiro R.G.
        • Spiro M.J.
        Philos. Trans. R. Soc. Lond. B Biol. Sci. 1982; 300: 117-127
        • Jaworek D.
        • Gruber W.
        • Bergmeyer H.U.
        Bergmeyer H.U. Methods in Enzymatic Analysis. Vol. 4. Academic Press, New York1974: 2097-2101
        • Bray G.A.
        Anal. Biochem. 1960; 1: 279-285
        • Heytler P.G.
        • Prichard W.W.
        Biochem. Biophys. Res. Commun. 1962; 7: 272-275
        • Carson D.D.
        • Earles B.J.
        • Lennarz W.J.
        J. Biol. Chem. 1981; 256: 11552-11557
        • Spiro M.J.
        • Spiro R.G.
        • Bhoyroo V.D.
        J. Biol. Chem. 1979; 254: 7668-7674
        • Stark N.J.
        • Heath E.C.
        Arch. Biochem. Biophys. 1979; 192: 599-609
        • Rearick J.I.
        • Chapman A.
        • Kornfeld S.
        J. Biol. Chem. 1981; 256: 6255-6261
        • Gershman H.
        • Robbins P.W.
        J. Biol. Chem. 1981; 256: 7774-7780
        • Turco S.J.
        • Pickard J.L.
        J. Biol. Chem. 1982; 257: 8674-8679
        • Datema R.
        • Schwarz R.T.
        J. Biol. Chem. 1981; 256: 11191-11198
        • Dumont J.E.
        • Vassart G.
        De Groot L.J. Endocrinology. Grune and Stratton Inc., New York1979: 311-329
        • Gregg C.T.
        Rothblat G.H. Christofalo V.J. Growth, Nutrition and Metabolism of Cells in Culture. Vol. 1. Academic Press, New York1972: 83-136
        • Spiro R.G.
        • Spiro M.J.
        • Bhoyroo V.D.
        J. Biol. Chem. 1979; 254: 7659-7667
        • Grinna L.S.
        • Robbins P.W.
        J. Biol. Chem. 1980; 255: 2255-2258
        • Elting J.J.
        • Chen W.W.
        • Lennarz W.J.
        J. Biol. Chem. 1980; 255: 2325-2331
        • Hubbard S.C.
        • Robbins P.W.
        J. Biol. Chem. 1980; 255: 11782-11793