Post-Translational Modification by Covalent Phosphorylation of Human Apolipoprotein B-100

Protein Kinase C-Mediated Regulation of Secreted apo B-100 in Hep G-2 Cells
  • Zafarul H. Beg
  • John A. Stonik
  • Jeffrey M. Hoeg
  • H. Bryan BrewerJr.


Within human plasma, apolipoprotein B exists as two antigenically-related isoproteins, designated apoB- 100 (Mr 512,000) and apoB-48 (Mr 250,000). The major apoB secreted in vitro by normal human hepatocytes and Hep G-2 cells is apoB-100 (Edge, et al., 1985). The peripheral metabolism of VLDL and apoB in part determine the level of circulating LDL (Dolphin, 1985). The LDL, possesing apoB-100 as the principal apolipoprotein constituent, are the major cholesterol transporting lipoproteins in human plasma. Since both LDLcholesterol (Grundy, 1986) and apoB-100 (Brunzell et al., 1984) levels are directly and positively correlated with premature coronary artery heart disease, an understanding of the control of hepatic apoB-100 synthesis and secretion is important. The human apolipoproteins have been demonstrated to undergo several co-translational and post-translational modifications including proteolytic cleavage (Gordon et al., 1983; Stoffel et al., 1983; Zannis et al, 1983; Bojanovski et al., 1984), glycosylation (Swaminathan and Aladjem, 1976; Lee and Breckenridge, 1967; Brewer et al., 1974; Zannis and Breslow, 1981), covalent phospholyration (Beg et al., 1989; Davis et al., 1984; Sparks et al., 1988 and Jackson et al., 1990), fatty acid acylation (Hoeg et al., 1986 and Hoeg et al., 1988) and deamidation (Ghisseli et al., 1985). These structural alterations may have important physiologic as well as pathologic roles.


Human Plasma Intracellular Degradation Human Apolipoprotein Premature Coronary Heart Disease Radioactive Band 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Allan, D., P. Thomas, and R. H. Michell. 1978. Rapid transbilayer diffusion of 1,2-diacylglycerol and its relevence to control of membrane curvature. Nature (london) 276: 289–290.CrossRefGoogle Scholar
  2. Beg, Z. H., J. A. Stonik, J. M. Hoeg, S. J. Demosky, Jr., T. Fairwell, and H. B. Brewer, Jr. 1989 Human apolipoprotein A-I: Post-translational modification by covalent phosphorylation, J. Biol. Chem. 264: 6913–6921.PubMedGoogle Scholar
  3. Beg, Z. H., J. A. Stonik, and H. B. Brewer, Jr. 1987. Phosphorylation and modulation of enzyme activity of nature and 2rotease cleaved purified hepatic 3-hydroxy-3methylglutaryl coenzyme A reductase by a calcium/calmodulin-dependent kinase. J. Biol. Chem. 262: 13228–13240.PubMedGoogle Scholar
  4. Bojanovski, D., R. E. Gregg, and H. B. Brewer, Jr. 1984. Tangier disease: in vitro conversion of proapoA-I Tangier to mature apoA-I Tangier. J. Biol. Chem. 259: 6049–6051.PubMedGoogle Scholar
  5. Bradford, M. M. 1976. A rapid and sensitive methods for the quantitation of microgram quantities of protein utilizing thr principle of protein-dye binding.Anal.Biochem. 72: 248–254.Google Scholar
  6. Brandt, H. Z. L. Capulong, and E.Y.C. Lee. 1975. Purification and properties of rabbit liver phosphorylase phosphatase. 250: 8038–8044.Google Scholar
  7. Brewer, H. B., Jr., R.Shulman, P.Herbert, R.Ronan, and K. Wehrly. 1974. The complete amino acid sequence of alanine apolipoprotein (apoC-III), an apolipoprotein from human plasma very low density lipoproteins.J.Biol. Chem. 249: 4975–4984.Google Scholar
  8. Brewer,H. B. Jr. 1981. Current concepts of molecular structure and metabolism of human apolipoproteins and lipoproteins. Klin. Wochschr. 59: 1023–1035.CrossRefGoogle Scholar
  9. Brunzell, J.D.A.D. Sniderman, J.J. Albers, and P.O. Kwiterovich, Jr. 1984. Apoprotein B and Al and coronary artery disease in humans.Arteriosclerosis 4: 79–83.Google Scholar
  10. Cardin, A.D., K. R. Witt, J. Chao, H. S. Margolius, V. H. Donaldson, and R. L. Jackson. 1984. Degradation of apolipoprotein B-100 of human plasma low density lipoproteins by tissue and plasma kallikreins. J.Biol. Chem. 259: 8522–8528.Google Scholar
  11. Capasso, J. M., T. W. Keenan, C. Aberjon, and C. B. Hirschberg. 1989. Mechanism of phosphorylation in the lumen of the Golgi apparatus: translocation of adenosine 5’-triphosphate in to Golgi vesicles from rat and mammary gland. J. Biol. Chem. 264: 5233–5240.PubMedGoogle Scholar
  12. Cohen,P. 1985. Thr role of protein phosphorylation in the hormonal control of enzyme activity. Eur.J. Biochem. 151: 439–448.CrossRefGoogle Scholar
  13. Davis, R.A., G.M.Clinton, R.A.Borchardt, M.MaloneMcNeal, T.Tan, and G.R. Lattier. 1984. Intrahepatic assembly of very low density lipopoproteins: phosphorylation of small molecular weight apolipoprotein B.J.Chem. 259: 3383–3386.Google Scholar
  14. Dolphin, P.J. 1985. Lipoprotein metabolism and the role of apolipoproteins as metabolic programmers.Can. J. Biochem.Cell Biol. 63: 850–869.CrossRefGoogle Scholar
  15. Edge, S.B., J.M.Hoeg, P.D.Schneider, and H.B.Brewer, Jr. 1985. Apolipoprotein B synthesis in man: liver synthesizes only apolipoprotein B-100. Metabolism. 34: 726–730.Google Scholar
  16. Engstrom, L., U. Zetterqvist, U. Ragnorson, P. Ekman, and U.Dahlqvist- Edberg. 1982. Cell function and diffrentiation, pp. 203–212. Alan R. Liss, New York.Google Scholar
  17. Ghisseli, G., M. F. Rohde, S. Tanenbaum, S. Krishnan, and A. M.Gotto. 1985. Origin of apolipoprotein A-I polymorphism in plasma. J. Biol. Chem. 29: 15662–15668.Google Scholar
  18. Gordon, J. I., H. F. Sims, S. R. Lentz, C. Edelstein, A. M. Scanu, and A. W. Strauss. 1983. Proteolytic processing of human preproapolipoprotein A-I: a proposed defect in the conversion of proA-I to A-I in Tangier’s disease. J. Biol. Chem. 258: 4037–4044.PubMedGoogle Scholar
  19. Grundy, S. M. 1986. Cholestrol and coronary heart disease. JAMA (J. Am. Med. Assoc.) 256: 2849–2858. Gofman, J. W., F. Glazier, A. Tomplin, B. Strisower, and O. De Lalla. 1954. Lipoproteins, coronary heart disease, and atherosclerosis. Physiol. Rev. 34: 589–607.Google Scholar
  20. Havel, R. J., H. A. Eder, and J. H. Bragdon. 1955. The distribution and chemical composition of ultracentrifugally seperated lipoproteins in human serum. J. Clin. Invest. 34: 1345–1353.PubMedCrossRefGoogle Scholar
  21. Hoeg, J. M., M. S. Meng, R. Ronan, T. Fairwell, and H. B. Brewer, Jr. 1986. Human apolipoprotein A-I: post-translational modification by atty acid acylation. J. Biol. Chem. 261: 3911–3914.PubMedGoogle Scholar
  22. Hoeg, J. M., M. S. Meng, R. Ronan, S. J. demosky, Jr., T. Fairwell, and H. B. Brewer, Jr. 1988. apolipoprotein B synthesized by Hep G-2 cells undergoes fatty acid acylation. J. Lipid. Res. 29: 1215–1220Google Scholar
  23. Hughes, T. E., J. M. Ordovas, and E. J. Schaefer. 1988. Regulation of apoliproteinB synthesis and secretion by caco-2 cells: lack of fatty acid effects and control by intracellular calcium ion. J. Biol. Chem. 263: 3425–3431.PubMedGoogle Scholar
  24. Hunter, T., and B. M. Sefton. 1980. Transforming gene product of Rous sarcoma virus phosphorylates tyrosine. Proc. Natl. Acad. Sci. U.S.A. 77: 1311–1315.PubMedCrossRefGoogle Scholar
  25. Jackson, T. K., A. I. Salhamck, J. Elovson, M. L. Diechman, and J. M. Amatruda. 1990. Insulin regulates apolipoprotein B turnover and phosphorylation in rat hepatocytes. J. Clin. Invest. 86: 1746–1751.PubMedCrossRefGoogle Scholar
  26. Kaibuchi, K., Y. Takai, M. Sawamura, M. Hoshijima, T. Fujikura, and Y. Nishizuka. 1983. Synergistic functions of protein phosphorylation and calcium mobilization in platelet activation. J. Biol. Chem. 258: 6701–6704.PubMedGoogle Scholar
  27. Knott, T. J., S. C. Rall, Jr., T. L. Innerarity, S. F. Jacobson, M. S. Urdea, Levy-Wilson, L. M. Bog Powell, R. J. Pease, R. Eddy, H. Nakai, M. Byers, L. M. Priestly, E. Robertson, L. B. Rall, C. Betsholtz, T. B. Shows, R. W. Mahley, and J. Scott. 1985. Human apolipoprotein B: structure of carboxyl-terminal domains, sites of gene expression, and chromosomal localization. Science 230: 37–43.PubMedCrossRefGoogle Scholar
  28. Knowles, B. B., C. C. Howe, and D. P. Aden. 1980. Human hepatocellular carcinoma cell lines secrete the major plasma proteins and hepatitis B surface antigen. Science. 209: 497–499.PubMedCrossRefGoogle Scholar
  29. Laemmli, U. K. 1970. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature (London). 227: 680–685.CrossRefGoogle Scholar
  30. Lee, P., and W. C. Breckenridge. 1967. The carbohydrate composition of human apo low density lipopoprotein from normal and type II hyperlipoproteinemic subjects. Can. J. Biochem. 52: 42–49.Google Scholar
  31. Mendez, A. J., J. F. Oram, and E. L. Bierman. 1991. Protein kinase C as a modulator of high density lipoprotein receptor-dependent efflux of intracellular cholesterol J. Biol. Chem. 266: 10104–10111.PubMedGoogle Scholar
  32. Muller, D., and H. Holzer. 1981. Regulation of fructose-1,6- Disphosphatase in yeast by phosphryla-tionldephosphorylation. Biochem.Biophys. Res. Commun. 103: 926–933.Google Scholar
  33. Osborne, J. C., and H. B. Brewer, Jr. 1977. The plasma lipoproteins. Adv. Protein Chem, 31: 253–337.PubMedCrossRefGoogle Scholar
  34. Parker, R. A., S. J. Miller, and D. M. Gibson. 1984. Phosphorylation of microsomal HMG-CoA reductase increases susceptibility to proteolytic degradaion in vitro. Biochem. Biophys. Res. Commun. 125: 629–635.PubMedCrossRefGoogle Scholar
  35. Parker, R. A., S. J. Miller, and D. M. Gibson. 1989. Phosphorylation Of native 97-kDa 3-hydroxy-3-methylglutaryl coenzyme A reductase from Rat liver: impact on activity and degradation of the enzyme. J. Biol. Chem. 264: 4877–4887.PubMedGoogle Scholar
  36. Pontremoli, S., E. Melloni, M. Michetti, B. Sparatore, F. Salamino, O.Sacco, and B. L. Horecker, 1987. Phosphorylation and proteolytic modification of specific cytoskeletal proteins in human neutrophils stimulated by phorbol 12-myristate 13- acetate. Proc. Natl. Acad. Sci. USA. 84: 3604–3608.Google Scholar
  37. Powell, M. A., and J. R. Glenrey. 1987. Regulation of calpactin I phospholipid binding by calpactin I light chain binding and phospho-rylation by P60“ re. Biochem. J. 247: 321–328.PubMedGoogle Scholar
  38. Sato, R. T. Imanaka, A. Takatsuki, and T. Takano. 1990. Degradation of newly synthesized apolipoprotein B-100 in a pre- Golgi compartment. J. Biol. Chem. 265: 11880–11884.PubMedGoogle Scholar
  39. Sparks, J D., C E. Sparks, A. M. Roncone, And J. M. Amatruda. 1988. Secretion of high and low molecular weight phosphorylated apolipoprotein B by hepatocytes from control and diabetic rats. J. Biol. Chem. 263: 5001–5004.PubMedGoogle Scholar
  40. Stoffel, W., E. Kruger, and R. DEutzmann 1983. Cell-free translation of human liver apolipoprotein A-I and A-II mRNA: processing of primary translation products. HoppeSeyler’s Z. Physiol. Chem. 364: 227–237.CrossRefGoogle Scholar
  41. Swaminathan, N., and F. Aladjem. 1976. The monosaccharide composition and sequence of the carbohydrate moiety of human serum low density lipoproteins. Biochemistry. 15: 1516–1522.PubMedCrossRefGoogle Scholar
  42. Wang, S.-Y., and D. L. Williams. 1982. Biosynthesis of vitellgenin: identification and characterization of non- phosphorylated precursors to avain vitellogenin I and vitellogenin II. J. Biol. Chem. 257: 3837–3846.PubMedGoogle Scholar
  43. Woodgett, J. R., and T. Hunter. 1987. Isolation and characterization of two distinct forms of protein kinase C. J. Biol. Chem. 262: 4863–4843.Google Scholar
  44. Yasuda, I., A. Kishimoto, S. Tanaka, M. Tominga, A. Sakurai, and Y. Nishizuka. 1990. A synthetic peptide substrate for selective assay of protein kinase C. Biochem. Biophys. Res. Commun. 166: 1220–1227.PubMedCrossRefGoogle Scholar
  45. Zannis, V.I., and J. L. Breslow. 1981 Human very low density lipopoprotein E isoprotein polymorphism is explained by genetic variation and post-translational modification. Biochemistry 20: 1033–1041Google Scholar
  46. Zannis, V. I., S. K. Karathanasis, H. Keutmann, G. Goldberger, and J. L. Breslow. 1983. Intracellular and extracellular processing of human apolipoprotein A-I isoprotein 2 is a propeptide. Proc. Natl. Acad.Sci. USA 80: 2574–2578.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1995

Authors and Affiliations

  • Zafarul H. Beg
  • John A. Stonik
    • 1
    • 2
  • Jeffrey M. Hoeg
    • 1
    • 2
  • H. Bryan BrewerJr.
    • 1
    • 2
  1. 1.Department of BiochemistryJ.N. Medical College, A.M.U.AligarhIndia
  2. 2.Molecular Disease BranchNational Institutes of HealthBethesdaUSA

Personalised recommendations