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In Vivo Induction of Tyrosylprotein Sulfotransferase by Ethanol: Role of Increased Enzyme Synthesis
Author(s) -
Ramaprasad Patalapati,
Kasinathan Chinnaswamy
Publication year - 1998
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/j.1530-0277.1998.tb03710.x
Subject(s) - ethanol , sulfation , in vivo , methionine , western blot , chemistry , enzyme , gastric mucosa , biochemistry , enzyme assay , medicine , endocrinology , stomach , biology , amino acid , microbiology and biotechnology , gene
Tyrosine sulfation is a posttranslational modification involved in the synthesis, secretion, and biological activity of proteins and peptides. Our previous studies have demonstrated that the enzyme activity was induced by ethanol. In the present work, the induction was studied in detail. Initial experiments were conducted to examine the time course of tyrosylprotein sulfotransferase (TPST) induction in rats pair‐fed liquid diets containing either ethanol or carbohydrate substitute (controls). Marked elevation of TPST activity (3‐fold) was measured on day 10 in the liver and gastric mucosa of ethanol‐fed rats. Ethanol‐mediated enhancement was also noticed by Western‐blot analysis with anti‐TPST antibody in both the liver and gastric mucosa on days 5 and 10. We then determined the steady‐state TPST protein turnover in ethanol‐fed and control animals that were given 35 S‐methionine after 10 days of pair‐feeding with liquid diet. The rates of TPST synthesis assessed by measuring initial rates of incorporation of 35 S‐methionine into TPST was increased in the liver and gastric mucosa of animals fed with ethanol. Monophasic exponential decay curves showed that TPST protein half‐lives for liver (control: 34 hr, ethanol: 32 hr) and gastric mucosa (control: 52 hr, ethanol: 48 hr) did not differ between control and ethanol groups. Our overall results indicate that the in vivo induction of TPST by ethanol involves increased enzyme synthesis rather than decreased enzyme degradation.