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：1978
卷号：75
期号：10
页码：4959-4961
DOI：10.1073/pnas.75.10.4959
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Quiescent 3T3 mouse fibroblast cells in a state of growth arrest due to serum deprivation were exposed to [14C]isoleucine. The cell cultures were then stimulated by the addition of 10% fetal calf serum. At various times after stimulation, the 14C-labeled cells were exposed to [3H]isoleucine. Cytoplasmic extracts from the double-labeled cells were subjected to sodium dodecyl sulfate/slab gel electrophoresis. By these procedures it was found that the relative rate of synthesis of a protein species of Mr 50,000 increased after stimulation of quiescent cells, reached a maximum at 5 hr, and then decreased before the 3T3 cells began to enter the S phase. The characteristic peaking profile of mid-G1 protein synthesis exhibited by the Mr 50,000 polypeptide can serve as a useful marker for the progression of events in G1 prior to exit into S.
