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：1994
卷号：91
期号：24
页码：11477-11481
DOI：10.1073/pnas.91.24.11477
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The immunosuppressant rapamycin (RAP) has been demonstrated to specifically inhibit the activity of p70 S6 kinase (p70s6k) and subsequent phosphorylation of ribosomal S6 protein in mammalian cells. Addition of RAP to proliferating lymphoid cells resulted in inhibition of protein synthesis before any changes in the rate of cell proliferation. When the cellular composition of proteins was examined by gel electrophoresis, RAP dramatically inhibited synthesis of selective proteins, particularly elongation factor 2 (eEF-2). The inhibition of eEF-2 synthesis by RAP was at the translational level. Further, RAP inhibited the polysomal association of mRNAs encoding not only eEF-2 but also elongation factor 1-alpha and ribosomal proteins without affecting mRNA translation of any of a number of nonribosomal proteins. Since levels of activity of p70s6k are correlated with the rate of biosynthesis of eEF-2, p70s6k might be involved in coordinate translational regulation of ribosomal protein mRNAs in higher eukaryotes, which have a conserved sequence at their 5' end. Specific inhibition of ribosomal protein synthesis likely explains the differential antiproliferative effect of RAP on proliferating and mitogen-activated quiescent cells.
