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. 1995 Jul 3;14(13):3080–3093. doi: 10.1002/j.1460-2075.1995.tb07311.x

The role of inositol acylation and inositol deacylation in GPI biosynthesis in Trypanosoma brucei.

M L Güther 1, M A Ferguson 1
PMCID: PMC394370  PMID: 7621823

Abstract

The compound diisopropylfluorophosphate (DFP) selectively inhibits an inositol deacylase activity in living trypanosomes that, together with the previously described phenylmethylsulfonyl fluoride (PMSF)-sensitive inositol acyltransferase, maintains a dynamic equilibrium between the glycosylphosphatidylinositol (GPI) anchor precursor, glycolipid A [NH2(CH2)2PO4-6Man alpha 1-2Man alpha 1-6Man alpha 1-4GlcN alpha 1-6myo-inositol-1-PO4-sn-1,2-dimyristoylglycerol], and its inositol acylated form, glycolipid C. Experiments using DFP in living trypanosomes and a trypanosome cell-free system suggest that earlier GPI intermediates are also in equilibrium between their inositol acylated and nonacylated forms. However, unlike mammalian and yeast cells, bloodstream form trypanosomes do not appear to produce an inositol acylated form of glucosaminylphosphatidylinositol (GlcN-PI). A specific function of inositol acylation in trypanosomes may be to enhance the efficiency of ethanolamine phosphate addition to the Man3GlcN-(acyl)PI intermediate. Inositol deacylation appears to be a prerequisite for fatty acid remodelling of GPI intermediates that leads to the exclusive presence of myristic acid in glycolipid A and, ultimately, in the variant surface glycoprotein (VSG). In the presence of DFP, the de novo synthesis of GPI precursors cannot proceed beyond glycolipid C' (the unremodelled version of glycolipid C) and lyso-glycolipid C'. Under these conditions glycolipid C'-type GPI anchors appear on newly synthesized VSG molecules. However, the efficiencies of both anchor addition to VSG and N-glycosylation of VSG were significantly reduced. A modified model of the GPI biosynthetic pathway in bloodstream form African trypanosomes incorporating these findings is presented.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bangs J. D., Hereld D., Krakow J. L., Hart G. W., Englund P. T. Rapid processing of the carboxyl terminus of a trypanosome variant surface glycoprotein. Proc Natl Acad Sci U S A. 1985 May;82(10):3207–3211. doi: 10.1073/pnas.82.10.3207. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bordier C. Phase separation of integral membrane proteins in Triton X-114 solution. J Biol Chem. 1981 Feb 25;256(4):1604–1607. [PubMed] [Google Scholar]
  3. Buxbaum L. U., Raper J., Opperdoes F. R., Englund P. T. Myristate exchange. A second glycosyl phosphatidylinositol myristoylation reaction in African trypanosomes. J Biol Chem. 1994 Dec 2;269(48):30212–30220. [PubMed] [Google Scholar]
  4. Cardoso de Almeida M. L., Turner M. J. The membrane form of variant surface glycoproteins of Trypanosoma brucei. Nature. 1983 Mar 24;302(5906):349–352. doi: 10.1038/302349a0. [DOI] [PubMed] [Google Scholar]
  5. Conzelmann A., Puoti A., Lester R. L., Desponds C. Two different types of lipid moieties are present in glycophosphoinositol-anchored membrane proteins of Saccharomyces cerevisiae. EMBO J. 1992 Feb;11(2):457–466. doi: 10.1002/j.1460-2075.1992.tb05075.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Costello L. C., Orlean P. Inositol acylation of a potential glycosyl phosphoinositol anchor precursor from yeast requires acyl coenzyme A. J Biol Chem. 1992 Apr 25;267(12):8599–8603. [PubMed] [Google Scholar]
  7. Cross G. A. Cellular and genetic aspects of antigenic variation in trypanosomes. Annu Rev Immunol. 1990;8:83–110. doi: 10.1146/annurev.iy.08.040190.000503. [DOI] [PubMed] [Google Scholar]
  8. Doering T. L., Lu T., Werbovetz K. A., Gokel G. W., Hart G. W., Gordon J. I., Englund P. T. Toxicity of myristic acid analogs toward African trypanosomes. Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):9735–9739. doi: 10.1073/pnas.91.21.9735. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Doering T. L., Masterson W. J., Englund P. T., Hart G. W. Biosynthesis of the glycosyl phosphatidylinositol membrane anchor of the trypanosome variant surface glycoprotein. Origin of the non-acetylated glucosamine. J Biol Chem. 1989 Jul 5;264(19):11168–11173. [PubMed] [Google Scholar]
  10. Doering T. L., Pessin M. S., Hart G. W., Raben D. M., Englund P. T. The fatty acids in unremodelled trypanosome glycosyl-phosphatidylinositols. Biochem J. 1994 May 1;299(Pt 3):741–746. doi: 10.1042/bj2990741. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Doering T. L., Pessin M. S., Hoff E. F., Hart G. W., Raben D. M., Englund P. T. Trypanosome metabolism of myristate, the fatty acid required for the variant surface glycoprotein membrane anchor. J Biol Chem. 1993 May 5;268(13):9215–9222. [PubMed] [Google Scholar]
  12. Doering T. L., Raper J., Buxbaum L. U., Adams S. P., Gordon J. I., Hart G. W., Englund P. T. An analog of myristic acid with selective toxicity for African trypanosomes. Science. 1991 Jun 28;252(5014):1851–1854. doi: 10.1126/science.1829548. [DOI] [PubMed] [Google Scholar]
  13. Englund P. T. The structure and biosynthesis of glycosyl phosphatidylinositol protein anchors. Annu Rev Biochem. 1993;62:121–138. doi: 10.1146/annurev.bi.62.070193.001005. [DOI] [PubMed] [Google Scholar]
  14. Ferguson M. A., Cross G. A. Myristylation of the membrane form of a Trypanosoma brucei variant surface glycoprotein. J Biol Chem. 1984 Mar 10;259(5):3011–3015. [PubMed] [Google Scholar]
  15. Ferguson M. A., Duszenko M., Lamont G. S., Overath P., Cross G. A. Biosynthesis of Trypanosoma brucei variant surface glycoproteins. N-glycosylation and addition of a phosphatidylinositol membrane anchor. J Biol Chem. 1986 Jan 5;261(1):356–362. [PubMed] [Google Scholar]
  16. Ferguson M. A., Homans S. W., Dwek R. A., Rademacher T. W. Glycosyl-phosphatidylinositol moiety that anchors Trypanosoma brucei variant surface glycoprotein to the membrane. Science. 1988 Feb 12;239(4841 Pt 1):753–759. doi: 10.1126/science.3340856. [DOI] [PubMed] [Google Scholar]
  17. Ferguson M. A., Masterson W. J., Homans S. W., McConville M. J. Evolutionary aspects of GPI metabolism in kinetoplastid parasites. Cell Biol Int Rep. 1991 Nov;15(11):991–1005. doi: 10.1016/0309-1651(91)90052-k. [DOI] [PubMed] [Google Scholar]
  18. Ferguson M. A., Murray P., Rutherford H., McConville M. J. A simple purification of procyclic acidic repetitive protein and demonstration of a sialylated glycosyl-phosphatidylinositol membrane anchor. Biochem J. 1993 Apr 1;291(Pt 1):51–55. doi: 10.1042/bj2910051. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Ferguson M. A. Site of palmitoylation of a phospholipase C-resistant glycosylphosphatidylinositol membrane anchor. Biochem J. 1992 Jun 1;284(Pt 2):297–300. doi: 10.1042/bj2840297. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Ferguson M. A. What can GPI do for you? Parasitol Today. 1994 Feb;10(2):48–52. doi: 10.1016/0169-4758(94)90392-1. [DOI] [PubMed] [Google Scholar]
  21. Field M. C. Inositol acylation of glycosylphosphatidylinositol membrane anchors: what it is, and why it may be important. Glycoconj J. 1992 Aug;9(4):155–159. doi: 10.1007/BF00731157. [DOI] [PubMed] [Google Scholar]
  22. Field M. C., Medina-Acosta E., Cross G. A. Characterization of a glycosylphosphatidylinositol membrane protein anchor precursor in Leishmania mexicana. Mol Biochem Parasitol. 1991 Oct;48(2):227–229. doi: 10.1016/0166-6851(91)90118-p. [DOI] [PubMed] [Google Scholar]
  23. Field M. C., Menon A. K., Cross G. A. A glycosylphosphatidylinositol protein anchor from procyclic stage Trypanosoma brucei: lipid structure and biosynthesis. EMBO J. 1991 Oct;10(10):2731–2739. doi: 10.1002/j.1460-2075.1991.tb07821.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Field M. C., Menon A. K., Cross G. A. Developmental variation of glycosylphosphatidylinositol membrane anchors in Trypanosoma brucei. Identification of a candidate biosynthetic precursor of the glycosylphosphatidylinositol anchor of the major procyclic stage surface glycoprotein. J Biol Chem. 1991 May 5;266(13):8392–8400. [PubMed] [Google Scholar]
  25. Field M. C., Menon A. K., Cross G. A. Developmental variation of glycosylphosphatidylinositol membrane anchors in Trypanosoma brucei. In vitro biosynthesis of intermediates in the construction of the GPI anchor of the major procyclic surface glycoprotein. J Biol Chem. 1992 Mar 15;267(8):5324–5329. [PubMed] [Google Scholar]
  26. Gerold P., Dieckmann-Schuppert A., Schwarz R. T. Glycosylphosphatidylinositols synthesized by asexual erythrocytic stages of the malarial parasite, Plasmodium falciparum. Candidates for plasmodial glycosylphosphatidylinositol membrane anchor precursors and pathogenicity factors. J Biol Chem. 1994 Jan 28;269(4):2597–2606. [PubMed] [Google Scholar]
  27. Gupta D., Tartakoff A., Tisdale E. Metabolic correction of defects in the lipid anchoring of Thy-1 in lymphoma mutants. Science. 1988 Dec 9;242(4884):1446–1448. doi: 10.1126/science.2904699. [DOI] [PubMed] [Google Scholar]
  28. Guther M. L., de Almeida M. L., Rosenberry T. L., Ferguson M. A. The detection of phospholipase-resistant and -sensitive glycosyl-phosphatidylinositol membrane anchors by western blotting. Anal Biochem. 1994 Jun;219(2):249–255. doi: 10.1006/abio.1994.1264. [DOI] [PubMed] [Google Scholar]
  29. Güther M. L., Masterson W. J., Ferguson M. A. The effects of phenylmethylsulfonyl fluoride on inositol-acylation and fatty acid remodeling in African trypanosomes. J Biol Chem. 1994 Jul 15;269(28):18694–18701. [PubMed] [Google Scholar]
  30. Hirose S., Prince G. M., Sevlever D., Ravi L., Rosenberry T. L., Ueda E., Medof M. E. Characterization of putative glycoinositol phospholipid anchor precursors in mammalian cells. Localization of phosphoethanolamine. J Biol Chem. 1992 Aug 25;267(24):16968–16974. [PubMed] [Google Scholar]
  31. Hirose S., Ravi L., Hazra S. V., Medof M. E. Assembly and deacetylation of N-acetylglucosaminyl-plasmanylinositol in normal and affected paroxysmal nocturnal hemoglobinuria cells. Proc Natl Acad Sci U S A. 1991 May 1;88(9):3762–3766. doi: 10.1073/pnas.88.9.3762. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Hirose S., Ravi L., Prince G. M., Rosenfeld M. G., Silber R., Andresen S. W., Hazra S. V., Medof M. E. Synthesis of mannosylglucosaminylinositol phospholipids in normal but not paroxysmal nocturnal hemoglobinuria cells. Proc Natl Acad Sci U S A. 1992 Jul 1;89(13):6025–6029. doi: 10.1073/pnas.89.13.6025. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Inoue N., Kinoshita T., Orii T., Takeda J. Cloning of a human gene, PIG-F, a component of glycosylphosphatidylinositol anchor biosynthesis, by a novel expression cloning strategy. J Biol Chem. 1993 Apr 5;268(10):6882–6885. [PubMed] [Google Scholar]
  34. Kamitani T., Menon A. K., Hallaq Y., Warren C. D., Yeh E. T. Complexity of ethanolamine phosphate addition in the biosynthesis of glycosylphosphatidylinositol anchors in mammalian cells. J Biol Chem. 1992 Dec 5;267(34):24611–24619. [PubMed] [Google Scholar]
  35. Krakow J. L., Doering T. L., Masterson W. J., Hart G. W., Englund P. T. A glycolipid from Trypanosoma brucei related to the variant surface glycoprotein membrane anchor. Mol Biochem Parasitol. 1989 Oct;36(3):263–270. doi: 10.1016/0166-6851(89)90174-6. [DOI] [PubMed] [Google Scholar]
  36. Lemansky P., Gupta D. K., Meyale S., Tucker G., Tartakoff A. M. Atypical mannolipids characterize Thy-1-negative lymphoma mutants. Mol Cell Biol. 1991 Aug;11(8):3879–3885. doi: 10.1128/mcb.11.8.3879. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Masterson W. J., Doering T. L., Hart G. W., Englund P. T. A novel pathway for glycan assembly: biosynthesis of the glycosyl-phosphatidylinositol anchor of the trypanosome variant surface glycoprotein. Cell. 1989 Mar 10;56(5):793–800. doi: 10.1016/0092-8674(89)90684-3. [DOI] [PubMed] [Google Scholar]
  38. Masterson W. J., Ferguson M. A. Phenylmethanesulphonyl fluoride inhibits GPI anchor biosynthesis in the African trypanosome. EMBO J. 1991 Aug;10(8):2041–2045. doi: 10.1002/j.1460-2075.1991.tb07734.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Masterson W. J., Raper J., Doering T. L., Hart G. W., Englund P. T. Fatty acid remodeling: a novel reaction sequence in the biosynthesis of trypanosome glycosyl phosphatidylinositol membrane anchors. Cell. 1990 Jul 13;62(1):73–80. doi: 10.1016/0092-8674(90)90241-6. [DOI] [PubMed] [Google Scholar]
  40. Mayor S., Menon A. K., Cross G. A., Ferguson M. A., Dwek R. A., Rademacher T. W. Glycolipid precursors for the membrane anchor of Trypanosoma brucei variant surface glycoproteins. I. Can structure of the phosphatidylinositol-specific phospholipase C sensitive and resistant glycolipids. J Biol Chem. 1990 Apr 15;265(11):6164–6173. [PubMed] [Google Scholar]
  41. Mayor S., Menon A. K., Cross G. A. Glycolipid precursors for the membrane anchor of Trypanosoma brucei variant surface glycoproteins. II. Lipid structures of phosphatidylinositol-specific phospholipase C sensitive and resistant glycolipids. J Biol Chem. 1990 Apr 15;265(11):6174–6181. [PubMed] [Google Scholar]
  42. Mayor S., Menon A. K., Cross G. A. Transfer of glycosyl-phosphatidylinositol membrane anchors to polypeptide acceptors in a cell-free system. J Cell Biol. 1991 Jul;114(1):61–71. doi: 10.1083/jcb.114.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. McConville M. J., Ferguson M. A. The structure, biosynthesis and function of glycosylated phosphatidylinositols in the parasitic protozoa and higher eukaryotes. Biochem J. 1993 Sep 1;294(Pt 2):305–324. doi: 10.1042/bj2940305. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Menon A. K. Biosynthesis of glycosyl-phosphatidylinositol. Cell Biol Int Rep. 1991 Nov;15(11):1007–1021. doi: 10.1016/0309-1651(91)90053-l. [DOI] [PubMed] [Google Scholar]
  45. Menon A. K., Eppinger M., Mayor S., Schwarz R. T. Phosphatidylethanolamine is the donor of the terminal phosphoethanolamine group in trypanosome glycosylphosphatidylinositols. EMBO J. 1993 May;12(5):1907–1914. doi: 10.1002/j.1460-2075.1993.tb05839.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Menon A. K., Mayor S., Schwarz R. T. Biosynthesis of glycosyl-phosphatidylinositol lipids in Trypanosoma brucei: involvement of mannosyl-phosphoryldolichol as the mannose donor. EMBO J. 1990 Dec;9(13):4249–4258. doi: 10.1002/j.1460-2075.1990.tb07873.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Menon A. K., Schwarz R. T., Mayor S., Cross G. A. Cell-free synthesis of glycosyl-phosphatidylinositol precursors for the glycolipid membrane anchor of Trypanosoma brucei variant surface glycoproteins. Structural characterization of putative biosynthetic intermediates. J Biol Chem. 1990 Jun 5;265(16):9033–9042. [PubMed] [Google Scholar]
  48. Menon A. K., Stevens V. L. Phosphatidylethanolamine is the donor of the ethanolamine residue linking a glycosylphosphatidylinositol anchor to protein. J Biol Chem. 1992 Aug 5;267(22):15277–15280. [PubMed] [Google Scholar]
  49. Mensa-Wilmot K., LeBowitz J. H., Chang K. P., al-Qahtani A., McGwire B. S., Tucker S., Morris J. C. A glycosylphosphatidylinositol (GPI)-negative phenotype produced in Leishmania major by GPI phospholipase C from Trypanosoma brucei: topography of two GPI pathways. J Cell Biol. 1994 Mar;124(6):935–947. doi: 10.1083/jcb.124.6.935. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Milne K. G., Ferguson M. A., Masterson W. J. Inhibition of the GlcNAc transferase of the glycosylphosphatidylinositol anchor biosynthesis in African trypanosomes. Eur J Biochem. 1992 Sep 1;208(2):309–314. doi: 10.1111/j.1432-1033.1992.tb17188.x. [DOI] [PubMed] [Google Scholar]
  51. Mohney R. P., Knez J. J., Ravi L., Sevlever D., Rosenberry T. L., Hirose S., Medof M. E. Glycoinositol phospholipid anchor-defective K562 mutants with biochemical lesions distinct from those in Thy-1- murine lymphoma mutants. J Biol Chem. 1994 Mar 4;269(9):6536–6542. [PubMed] [Google Scholar]
  52. Proudfoot L., Schneider P., Ferguson M. A., McConville M. J. Biosynthesis of the glycolipid anchor of lipophosphoglycan and the structurally related glycoinositolphospholipids from Leishmania major. Biochem J. 1995 May 15;308(Pt 1):45–55. doi: 10.1042/bj3080045. [DOI] [PMC free article] [PubMed] [Google Scholar]
  53. Puoti A., Conzelmann A. Characterization of abnormal free glycophosphatidylinositols accumulating in mutant lymphoma cells of classes B, E, F, and H. J Biol Chem. 1993 Apr 5;268(10):7215–7224. [PubMed] [Google Scholar]
  54. Puoti A., Conzelmann A. Structural characterization of free glycolipids which are potential precursors for glycophosphatidylinositol anchors in mouse thymoma cell lines. J Biol Chem. 1992 Nov 5;267(31):22673–22680. [PubMed] [Google Scholar]
  55. Puoti A., Desponds C., Fankhauser C., Conzelmann A. Characterization of glycophospholipid intermediate in the biosynthesis of glycophosphatidylinositol anchors accumulating in the Thy-1-negative lymphoma line SIA-b. J Biol Chem. 1991 Nov 5;266(31):21051–21059. [PubMed] [Google Scholar]
  56. Ralton J. E., Milne K. G., Güther M. L., Field R. A., Ferguson M. A. The mechanism of inhibition of glycosylphosphatidylinositol anchor biosynthesis in Trypanosoma brucei by mannosamine. J Biol Chem. 1993 Nov 15;268(32):24183–24189. [PubMed] [Google Scholar]
  57. Richier P., Arpagaus M., Toutant J. P. Glycolipid-anchored acetylcholinesterases from rabbit lymphocytes and erythrocytes differ in their sensitivity to phosphatidylinositol-specific phospholipase C. Biochim Biophys Acta. 1992 Nov 23;1112(1):83–88. doi: 10.1016/0005-2736(92)90257-m. [DOI] [PubMed] [Google Scholar]
  58. Roberts W. L., Myher J. J., Kuksis A., Low M. G., Rosenberry T. L. Lipid analysis of the glycoinositol phospholipid membrane anchor of human erythrocyte acetylcholinesterase. Palmitoylation of inositol results in resistance to phosphatidylinositol-specific phospholipase C. J Biol Chem. 1988 Dec 15;263(35):18766–18775. [PubMed] [Google Scholar]
  59. Schenkman S., Yoshida N., Cardoso de Almeida M. L. Glycophosphatidylinositol-anchored proteins in metacyclic trypomastigotes of Trypanosoma cruzi. Mol Biochem Parasitol. 1988 Jun;29(2-3):141–151. doi: 10.1016/0166-6851(88)90069-2. [DOI] [PubMed] [Google Scholar]
  60. Schneider P., Ralton J. E., McConville M. J., Ferguson M. A. Analysis of the neutral glycan fractions of glycosyl-phosphatidylinositols by thin-layer chromatography. Anal Biochem. 1993 Apr;210(1):106–112. doi: 10.1006/abio.1993.1158. [DOI] [PubMed] [Google Scholar]
  61. Singh N., Singleton D., Tartakoff A. M. Anchoring and degradation of glycolipid-anchored membrane proteins by L929 versus by LM-TK- mouse fibroblasts: implications for anchor biosynthesis. Mol Cell Biol. 1991 May;11(5):2362–2374. doi: 10.1128/mcb.11.5.2362. [DOI] [PMC free article] [PubMed] [Google Scholar]
  62. Singh N., Zoeller R. A., Tykocinski M. L., Lazarow P. B., Tartakoff A. M. Addition of lipid substituents of mammalian protein glycosylphosphoinositol anchors. Mol Cell Biol. 1994 Jan;14(1):21–31. doi: 10.1128/mcb.14.1.21. [DOI] [PMC free article] [PubMed] [Google Scholar]
  63. Sipos G., Puoti A., Conzelmann A. Glycosylphosphatidylinositol membrane anchors in Saccharomyces cerevisiae: absence of ceramides from complete precursor glycolipids. EMBO J. 1994 Jun 15;13(12):2789–2796. doi: 10.1002/j.1460-2075.1994.tb06572.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  64. Stevens V. L., Zhang H. Coenzyme A dependence of glycosylphosphatidylinositol biosynthesis in a mammalian cell-free system. J Biol Chem. 1994 Dec 16;269(50):31397–31403. [PubMed] [Google Scholar]
  65. Sugiyama E., DeGasperi R., Urakaze M., Chang H. M., Thomas L. J., Hyman R., Warren C. D., Yeh E. T. Identification of defects in glycosylphosphatidylinositol anchor biosynthesis in the Thy-1 expression mutants. J Biol Chem. 1991 Jul 5;266(19):12119–12122. [PubMed] [Google Scholar]
  66. Tomavo S., Dubremetz J. F., Schwarz R. T. A family of glycolipids from Toxoplasma gondii. Identification of candidate glycolipid precursor(s) for Toxoplasma gondii glycosylphosphatidylinositol membrane anchors. J Biol Chem. 1992 Jun 15;267(17):11721–11728. [PubMed] [Google Scholar]
  67. Tomavo S., Dubremetz J. F., Schwarz R. T. Biosynthesis of glycolipid precursors for glycosylphosphatidylinositol membrane anchors in a Toxoplasma gondii cell-free system. J Biol Chem. 1992 Oct 25;267(30):21446–21458. [PubMed] [Google Scholar]
  68. Toutant J. P., Richards M. K., Krall J. A., Rosenberry T. L. Molecular forms of acetylcholinesterase in two sublines of human erythroleukemia K562 cells. Sensitivity or resistance to phosphatidylinositol-specific phospholipase C and biosynthesis. Eur J Biochem. 1990 Jan 12;187(1):31–38. doi: 10.1111/j.1432-1033.1990.tb15274.x. [DOI] [PubMed] [Google Scholar]
  69. Urakaze M., Kamitani T., DeGasperi R., Sugiyama E., Chang H. M., Warren C. D., Yeh E. T. Identification of a missing link in glycosylphosphatidylinositol anchor biosynthesis in mammalian cells. J Biol Chem. 1992 Apr 5;267(10):6459–6462. [PubMed] [Google Scholar]
  70. Vidugiriene J., Menon A. K. Early lipid intermediates in glycosyl-phosphatidylinositol anchor assembly are synthesized in the ER and located in the cytoplasmic leaflet of the ER membrane bilayer. J Cell Biol. 1993 Jun;121(5):987–996. doi: 10.1083/jcb.121.5.987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  71. Vidugiriene J., Menon A. K. The GPI anchor of cell-surface proteins is synthesized on the cytoplasmic face of the endoplasmic reticulum. J Cell Biol. 1994 Oct;127(2):333–341. doi: 10.1083/jcb.127.2.333. [DOI] [PMC free article] [PubMed] [Google Scholar]
  72. Wong Y. W., Low M. G. Biosynthesis of glycosylphosphatidylinositol-anchored human placental alkaline phosphatase: evidence for a phospholipase C-sensitive precursor and its post-attachment conversion into a phospholipase C-resistant form. Biochem J. 1994 Jul 1;301(Pt 1):205–209. doi: 10.1042/bj3010205. [DOI] [PMC free article] [PubMed] [Google Scholar]
  73. Wong Y. W., Low M. G. Phospholipase resistance of the glycosyl-phosphatidylinositol membrane anchor on human alkaline phosphatase. Clin Chem. 1992 Dec;38(12):2517–2525. [PubMed] [Google Scholar]
  74. Zamze S. E., Wooten E. W., Ashford D. A., Ferguson M. A., Dwek R. A., Rademacher T. W. Characterisation of the asparagine-linked oligosaccharides from Trypanosoma brucei type-I variant surface glycoproteins. Eur J Biochem. 1990 Feb 14;187(3):657–663. doi: 10.1111/j.1432-1033.1990.tb15350.x. [DOI] [PubMed] [Google Scholar]

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