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：1993
卷号：90
期号：16
页码：7613-7617
DOI：10.1073/pnas.90.16.7613
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Ferritin synthesis, maintained at a very low basal rate when extracellular iron levels are low, is elevated up to 50-fold when iron levels are increased. Previous examinations of this iron-dependent activation have concluded that changes in ferritin synthesis results from selective translational activation conferred by an "iron response element" that lies near the 5' terminus of all known ferritin mRNAs. By placing an iron response element in an optimal position in other mRNAs, we find the iron response element to be a potent translational repressor whose influence can only partially be abrogated under optimal inducing conditions. Further, we show that the 25- to 50-fold iron-mediated increase in ferritin synthesis results from coupling a 5- to 6-fold iron-dependent translational derepression with a similar 5- to 6-fold nuclear-dependent increase in mRNA level.
