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Regulation of the eIF2/eIF2B system during alcohol‐induced inhibition of hepatic protein synthesis in rats
Author(s) -
Karinch Anne M,
Vary Thomas C
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.949.1
Subject(s) - alcohol , ethanol , eif2 , medicine , endocrinology , phosphorylation , protein biosynthesis , biology , biochemistry , translation (biology) , messenger rna , gene
Alcohol abuse damages hepatic structure and function. The effect of alcohol ingestion on protein synthesis and initiation factors eIF2 and eIF2B in rat liver was studied 1) after acute and chronic ethanol, 2) in males and females after chronic alcohol intake, and 3) after acute alcohol withdrawal. Protein synthesis was measured by incorporation of [ 3 H]‐phenylalanine into liver protein and eIF2/eIF2B content and phosphorylation were determined by immunoblot. Protein synthesis was inhibited 37% after acute and 30% after chronic (>8 wk) ethanol and was associated with 65% increase in eIF2α phosphorylation in either case. eIF2 content decreased in rats fed alcohol for >12 weeks. Basal protein synthesis was 34% higher in females than in males and alcohol‐induced inhibition was greater in females (34%) than in males (19%). Withdrawal of alcohol reversed eIF2α phosphorylation but not the eIF2 deficit so hepatic protein synthesis was partially restored. Acute alcohol administration did not affect eIF2B content or eIF2Bε phosphorylation in male rats whereas chronic alcohol feeding revealed sex‐differential changes in both. eIF2B content in livers from males increased in the alcohol group but decreased in females; eIF2Bε phosphorylation decreased in males and increased in females. Changes in hepatic protein synthesis induced by alcohol consumption reflect underlying alterations in eIF2/eIF2B. NIH R21AA015349