Adenovirus infection elevates levels of cellular topoisomerase I
The authors have developed a specific, sensitive, and quantitative assay for topoisomerase I, which is based on the formation of a covalent enzyme-DNA intermediate. The assay measures the quantitative transfer of TSP radioactivity from TSP-labeled DNA to topoisomerase I. Since TSP-labeled topoisomerase molecules are resolved by NaDodSO4/PAGE, HeLa topoisomerase I (100 kDa) and calf thymus topoisomerase I (82 kDa) can be quantitatively assayed in the same reaction mixture. The assay can detect at least 0.3 ng (3 fmol) of topoisomerase I. They have used their assay to measure the levels of topoisomerase I activity in crude extracts of nuclei prepared from uninfected, adenovirus-infected, and adenovirus-transformed human cells. The evidence suggests that an adenovirus early gene product, presumably a protein encoded in early region 1A (E1A), increases cellular topoisomerase I activity at least 10-fold.
- Research Organization:
- Oregon State Univ., Corvallis
- OSTI ID:
- 6289452
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 82:8; ISSN PNASA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
ADENOVIRUS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
COMPLEXES
DAYS LIVING RADIOISOTOPES
DNA
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
HELA CELLS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOMERASES
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ONCOGENIC VIRUSES
ORGANIC COMPOUNDS
PARASITES
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PROTEINS
RADIOENZYMATIC ASSAY
RADIOISOTOPES
VIRUSES