Open AccessGlucocorticoid inhibition of initiation of transcription of the DNA encoding rRNA (rDNA) in lymphosarcoma P1798 cells.
Author(s) -
Alice H. Cavanaugh,
P K Gokal,
Robert P. Lawther,
E. Aubrey Thompson
Publication year - 1984
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.81.3.718
Subject(s) - microbiology and biotechnology , transcription (linguistics) , biology , rna polymerase ii , rna , in vitro , dna , rna polymerase i , ribosomal rna , rna polymerase , cell culture , gene , messenger rna , gene expression , promoter , biochemistry , genetics , philosophy , linguistics
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.