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：1984
卷号：81
期号：3
页码：718-721
DOI：10.1073/pnas.81.3.718
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Cell-free extracts of lymphosarcoma P1798 cell culture lines support faithful initiation upon the cloned mouse DNA encoding rRNA (rDNA) promoter, whereas extracts from cells treated for 16 hr with 0.1 microM dexamethasone cannot. Extracts from both sources transcribe the cloned 5S RNA gene in vitro and mixing experiments further demonstrate that inhibition of transcription of rDNA in vitro is not due to nucleases or inhibitors of transcription present in extracts from glucocorticoid-treated cells. Incubation of extracts from control cells at 45 degrees C for 15 min inactivates RNA polymerase I and abolishes transcription. Activity can be restored by the addition of partially purified RNA polymerase I from control cells and hormone-treated cells. Moreover, extracts from hormone treated cells can be reconstituted by the addition of a partially purified, heat-stable transcription factor from control cells.
