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Rapid induction of c-fos transcription reveals quantitative linkage of RNA polymerase II and DNA topoisomerase I enzyme activities.
- Source :
-
Cell [Cell] 1990 Jan 12; Vol. 60 (1), pp. 141-9. - Publication Year :
- 1990
-
Abstract
- The functional association between DNA topoisomerase I and gene activity has been analyzed using the tightly regulated c-fos proto-oncogene, which undergoes rapid transitions between active and inactive states of transcription. We show that the topoisomerase I inhibitor camptothecin can be used to measure topoisomerase I activity throughout the transcription cycle of the c-fos gene. Upon induction of c-fos transcription in the presence of camptothecin, topoisomerase I cleavages spread through the gene in the 5' to 3' direction and concomitantly transcriptional elongation is retarded. Parallel kinetic measurements of RNA polymerase II activity and topoisomerase I activity demonstrate a quantitative and temporal link between the two enzymes. Our results argue that topoisomerase I quantitatively relieves the torsional consequences of transcriptional elongation in intact cells.
- Subjects :
- Animals
Blotting, Northern
Calcimycin pharmacology
Camptothecin pharmacology
Cell Line
Dimethyl Sulfoxide pharmacology
Gene Expression Regulation
Humans
Kinetics
Plasmids
Proto-Oncogene Mas
Proto-Oncogene Proteins c-fos
RNA, Messenger analysis
Restriction Mapping
Thymus Gland enzymology
DNA Topoisomerases, Type I metabolism
Protein-Tyrosine Kinases genetics
Proto-Oncogene Proteins genetics
Proto-Oncogenes drug effects
RNA Polymerase II metabolism
Transcription, Genetic
Subjects
Details
- Language :
- English
- ISSN :
- 0092-8674
- Volume :
- 60
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Cell
- Publication Type :
- Academic Journal
- Accession number :
- 2153054
- Full Text :
- https://doi.org/10.1016/0092-8674(90)90724-s