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Atp-bound topoisomerase ii as a target for antitumor drugs.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2001 May 11; Vol. 276 (19), pp. 15990-5. Date of Electronic Publication: 2001 Feb 23. - Publication Year :
- 2001
-
Abstract
- Topoisomerase II (TOP2) poisons interfere with the breakage/reunion reaction of TOP2 resulting in DNA cleavage. In the current studies, we show that two different classes (ATP-sensitive and -insensitive) of TOP2 poisons can be identified based on their differential sensitivity to the ATP-bound conformation of TOP2. First, in the presence of 1 mm ATP or the nonhydrolyzable analog adenosine 5'-(beta,gamma-imino)triphosphate, TOP2-mediated DNA cleavage induced by ATP-sensitive TOP2 poisons (e.g. doxorubicin, etoposide, mitoxantrone, and 4'-(9-acridinylamino)methanesulfon-m-anisidide) was 30-100-fold stimulated, whereas DNA cleavage induced by ATP-insensitive TOP2 poisons (e.g. amonafide, batracylin, and menadione) was only slightly (less than 3-fold) affected. In addition, ADP was shown to strongly antagonize TOP2-mediated DNA cleavage induced by ATP-sensitive but not ATP-insensitive TOP2 poisons. Second, C427A mutant human TOP2alpha, which exhibits reduced ATPase activity, was shown to exhibit cross-resistance to all ATP-sensitive but not ATP-insensitive TOP2 poisons. Third, using ciprofloxacin competition assay, TOP2-mediated DNA cleavage induced by ATP-sensitive but not ATP-insensitive poisons was shown to be antagonized by ciprofloxacin. These results suggest that ATP-bound TOP2 may be the specific target of ATP-sensitive TOP2 poisons. Using Lac repressor-operator complexes as roadblocks, we show that ATP-bound TOP2 acts as a circular clamp capable of entering DNA ends and sliding on unobstructed duplex DNA.
- Subjects :
- Amino Acid Substitution
Amsacrine pharmacology
Animals
Cattle
DNA Topoisomerases, Type II drug effects
Doxorubicin pharmacology
Etoposide pharmacology
Kinetics
Mitoxantrone pharmacology
Mutagenesis, Site-Directed
Recombinant Proteins chemistry
Recombinant Proteins drug effects
Recombinant Proteins metabolism
Teniposide pharmacology
Thymus Gland enzymology
Adenosine Triphosphate metabolism
Antineoplastic Agents pharmacology
DNA Topoisomerases, Type II chemistry
DNA Topoisomerases, Type II metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 276
- Issue :
- 19
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 11278845
- Full Text :
- https://doi.org/10.1074/jbc.M011143200