Role of sulfation in the processing of gastric mucins

• Autorzy: Liau Y.H. , Murty V. L. N. , Slomiany A. , Bielanski W. , Slomiany B. L.
• Języki publikacji: EN

Abstrakty

EN

The role of sulfation in the processing of mucus glycoprotein in gastric mucosa was investigated. Rat gastric mucosal segments were incubated in MEM at various medium sulfate concentrations in the presence of [³⁵S]Na₂ SO₄ [³H] glucosamine and [³H]proline, with and without chlorate an inhibitor of PAPS formation. The results revealed that the mucin sulfation attained maximum at 300 µM medium sulfate concentration. Introduction of chlorate into the incubation medium, while having no effect on the protein synthesis as evidenced by [³H]proline incorporation, caused at its optimal concentration of 2 mM a 90% decrease in mucin sulfation and a 40% drop in mucin glycosylation. Evaluation of mucin molecular forms distribution indicated the predominance of the high molecular mucin form in the interacellular fraction and the low molecular mucin from in the extracellular fraction. Increase in medium sulfate caused an increase in the high molecular weight mucin form in both fractions, and this effect was inhibited by chlorate. Also, higher medium sulfate concentrations led to a higher degree of sulfation in the high molecular weight mucin form, the effect of which was inhibited by chlorate. The results suggest that the sulfation process is an early event taking place at the stage of mucin subunit assembly and is required for mucin polymer formation. Hence, the disturbances in mucin sulfation process could be determinal to the maintenance of gastric mucus coat integrity.

Słowa kluczowe

EN

gastric mucosa; synthesis; sulphation; glycoprotein; protein synthesis; endoplasmic reticulum; glycosylation

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 1991
• Tom: 42
• Numer: 4
• Opis fizyczny: p.357-366,fig.,ref.

Twórcy

autor

Liau Y.H.

• Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA

autor

Murty V. L. N.

• Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA

autor

Slomiany A.

• Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA

autor

Bielanski W.

• Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA

autor

Slomiany B. L.

• Research Center, New Jersey Dental School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey, USA

Bibliografia

• 1. Slomiany BL, Sarosiek J,Slomiany A. Gastric mucus and the mucosal barrier. Dig Dis 1987; 5: 125-145.
• 2. Schachter H, Williams D. Biosynthesis of mucus glycoproteins. In: Chantler EN. Elder JB, Eistein M, eds. Mucus in Health and Disease-II. New York: Plenum Press. 1982; 3-28.
• 3. Neutra MR, Forstner JF. Gastrointestinal mucus: synthesis, secretion and function. In: Johnson LR, ed. Physiology of the Gastrointestinal Tract. New York: Raven Press. 1987; 975-1009.
• 4. Straus GJAM. Initial glycosidation of protein with acetylgalactosaminylserin linkages. Proc Natl Acad Sci USA; 1979; 76: 2694-2698.
• 5. Slomiany BL, Tsukada H, Slomiany A. Cotranslational attachment of fatty acids to nascent peptides m gastric mucus glycoprotein. Biochem Biophys Res Commun 1986; 141: 387-393.
• 6. Slomiany BL, Meyer K. Isolation and structural studies of sulfated glycoproteins of hog gastric mucosa. J Biol Ghent 1972; 247: 5062-5070.
• 7. Robbins PW, Lipman J. Enzymatic synthesis of adenosine-5’-phosphosulfate. J Biol Chem 1958; 233: 686-690.
• 8. Levi AS, Wolf G. Purification and properties of the enzyme ATP-sulfurylase and its relation to vitamin A. Biochim Biophys Acta 1969; 172: 262-282.
• 9. Robbins PW, Lipmann F. Separation of the two enzymatic phases in active sulfate synthesis. J Biol Chem 1959; 233: 681-685.
• 10. Carter SR, Slomiany A, Gwozdzinski K, Liau YH, Slomiany BL. Enzymatic sulfation of mucus glycoprotein in gastric mucosa. J Biol Chem 1988; 263; 11977-11984.
• 11. Jentjens T, Strous GJ. Quantitative aspects of mucus glycoprotein biosynthesis. Biochem J 1985; 228: 227-232.
• 12. Sobue M, Takeuchi J, Ito K, Kimata K, Suzuki S. Effect of environmental sulfate concentration on the synthesis of low and high sulfates by chick embryo cartilage. J Biol Chem 1978; 253: 6190-6196.
• 13. Ito K, Sobue M, Suzuki S. Altered proteoglycan synthesis by epiphyseal cartilages in culture at low SO₄ concentration. J Biol Chem 1982; 257: 917-923.
• 14. Hamphries DE, Silbert CK, Silbert JE. Glycosaminoglycan production by bovine aortic endothelial cells cultured in sulfate-depleted medium. J Biol Chem 1986; 261: 9122-9127.
• 15. Farley JR, Nakayama G, Fryns D, Segel JH. Adenosine triphosphate sulfurylase from penicillium chrysogenum. Equilibrium binding, substrate hydrolysis and isotope exchange studies. Arch Biochem Biophys 1978; 185: 376-390.
• 16. Burnell JN, Roy AB. Purification and properties of the ATP sulfurylase of rat liver. Biochim Biophys Acta 1978; 527: 239-248.
• 17. Liau YH, Horowitz MI, Incorporation in vitro of [³H] glucosamine or [³H] glucose and [³⁵S]SO₄ into rat gastric mucosa. J Biol Chem 1982; 257 : 4709-4718.
• 18. Slomiany BL, Takagi A, Liau YH, Jozwiak Z, Slomiany A. In vitro acylation of rat gastric glycoprotein with |³H] palmitic acid. J Biol Chem 1984; 259: 11997-12000.
• 19. Van Beurden-Lamers WMO, Spee-Brand R, Dekker J, Stiaus GJ. Sulphation causes heterogeneity of gasric mucins. Biochem Biophys Acta 1989; 990: 232-239.
• 20. Azuumi Y, Ohara S, Ishihara K, Okabe H, Hotta K. Correlation of quantitative changes of gastric mucosal glycoprotein with aspirin induced damage in rats. Gut 1980; 21: 533-536.
• 21. Murakami S, Mori Y. Changes in the incorporating activity of ³⁵S-sulfate into gastric sulfated glycoproteins in the rat with erosin by restraint and water immersion. Jap J Pharmac 1984; 35. 279-286.
• 22. Younan F, Pearson J, Allen A. Venables C. Changes in the structure of the mucus gel in the mucosal surface of the stomach in association with peptic ulcer disease. Gastroenterology 1982; 82: 827-831.