Tunicamycin prevents stimulation of protein synthesis by branched chain amino acids in isolated rat muscles.
Quarter rat diaphragms were incubated for 150 min. with or without stimulators of protein synthesis and/or inhibitors of protein glycosylation. Tyrosine incorporation into protein was measured during the last 120 min. Branched chain amino acids stimulated protein synthesis by 40-60%. Tunicamycin or 2-deoxy-D-glucose did not affect baseline protein synthesis, but inhibited or abolished stimulation of protein synthesis by branched chain amino acids. Tunicamycin did not prevent stimulation of protein synthesis by insulin or affect amino acid transport under these conditions. The data suggest that a) glycoprotein(s) may be involved in the post-transcriptional stimulation of protein synthesis by leucine, b) leucine and insulin may stimulate peptide chain initiation in muscle through different mechanisms.
D000597:Amino Acids, Branched-Chain / Q000494:pharmacology*; D000818:Animals; D003847:Deoxyglucose / Q000494:pharmacology; D005944:Glucosamine / Q000031:analogs & derivatives*; D007328:Insulin / Q000494:pharmacology; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D014176:Protein Biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014415:Tunicamycin / Q000494:pharmacology*
D000597:Amino Acids, Branched-Chain; D007328:Insulin; D014415:Tunicamycin; D003847:Deoxyglucose; D005944:Glucosamine