title: Physiology of rat-liver polysomes. Protein synthesis by stable polysomes.
abstract: Certain qualitative aspects of protein synthesis in the livers of starved, starved-re-fed and actinomycin D-treated rats have been examined by polyacrylamide-gel electrophoresis. Animals were exposed to a mixture of (14)C-labelled acids for 18-20min. and killed, and an ultrasonic extract of newly formed protein in microsomal vesicles was prepared and examined by gel electrophoresis. In normal and starved-re-fed animals, 27% of the newly synthesized protein was albumin. During starvation, when RNA synthesis was decreased, the percentage of newly formed protein as albumin rose. After actinomycin D treatment of starved-re-fed rats, when only stable messenger RNA persisted in the cytoplasm, albumin synthesis increased to 63% of the total. This finding suggested that albumin was the primary protein synthesized on stable messenger RNA.
mesh_terms: D000418:Albumins / Q000096:biosynthesis*; D000818:Animals; D002247:Carbon Isotopes; D003609:Dactinomycin / Q000494:pharmacology; D004032:Diet; D004586:Electrophoresis; D005260:Female; D005779:Immunodiffusion; D007274:Injections, Intraperitoneal; D008099:Liver / Q000378:metabolism*; D008861:Microsomes / Q000032:analysis; D014176:Protein Biosynthesis; D012333:RNA, Messenger; D051381:Rats; D012270:Ribosomes / Q000378:metabolism*; D013217:Starvation; D014465:Ultrasonics
chemical_list: D000418:Albumins; D002247:Carbon Isotopes; D012333:RNA, Messenger; D003609:Dactinomycin