期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1972
卷号：69
期号：10
页码：2937-2941
DOI：10.1073/pnas.69.10.2937
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Proteins labeled in cultured hepatoma cells grown in the presence of radioactive amino acids and pactamycin consist primarily of growing polypeptide chains initiated before addition of the antibiotic. Nascent tyrosine aminotransferase (EC 2.6.1.5 ) molecules were labeled in this way, and their radioactivity after completion was measured immunologically. Cells exposed to the synthetic adrenal steroid, dexamethasone, contain 10- to 18- times as much nascent enzyme as uninduced cells. These results indicate that induction control is not at the level of polypeptide-chain elongation or release, but probably operates on either the amount of messenger RNA or the rate of specific polypeptide-chain initiation.
