Muscle protein biosynthesis in the tumour-bearing rat. A defect in a post-initiation stage of translation

• Published in: Biochimica et biophysica acta Vol. 378; no. 2; pp. 230 - 240
• Main Authors: Clark, C M, Goodlad, G A
• Format: Journal Article
• Language: English
• Published: Netherlands 20.01.1975
• Subjects: Animals; Carcinoma 256, Walker - metabolism; Cyclohexanecarboxylic Acids - pharmacology; Muscle Proteins - biosynthesis; Muscles - metabolism; Neoplasm Proteins - biosynthesis; Phenylalanine - metabolism; Polyribosomes - metabolism; Protein Biosynthesis - drug effects; Rats; Ribosomes - drug effects; Ribosomes - metabolism
• ISSN: 0006-3002
• DOI: 10.1016/0005-2787(75)90111-2

1. The decreased ability of polysomes isolated from the gastrocnemius of rats bearing the Walker 256 carcinoma to incorporate L-[14C]leucine into protein persisted in the presence of 5-10-5 M aurin tricarboxylic acid and 1-10-2 M NaF. 2. Poly(U)-directed phenylalanine incorporation by such polysome preparations was less than that of similar preparations from normal rats. 3. The ability of gastrocnemius polysomes from tumour-bearing rats to react with puromycin was markedly decreased. Cycloheximide inhibited peptidyl puromycin formation by polysome preparations from both normal and tumour-bearing rats. 4. The ability of recombined 60 S and 40 S subunits prepared from polysomes of tumour-bearing rats to carry out poly(U)-directed polyphenylalanine synthesis was much reduced when assayed over a wide range of magnesium concentrations. Cross-over experiments with subunits from normal and tumour-bearing animals suggested that this was due to a defect in the smaller ribosomal subunit.