Bacteriophage T4 DNA topoisomerase is the target of antitumor agent 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) in T4-infected Escherichia coli.

AUTOR(ES)

Huff, A C

RESUMO

The mammalian type II DNA topoisomerase has been proposed to be the intracellular target of a variety of antitumor agents, including m-AMSA [4'-(9-acridinylamino)-methanesulfon-m-anisidide]. Because the bacteriophage T4-encoded topoisomerase resembles the mammalian enzyme, we are using T4 as a simple model system to investigate the mechanism of action of m-AMSA. A mutation that renders T4 growth m-AMSA-resistant is closely linked to an amber mutation in T4 gene 39, which encodes one of the topoisomerase subunits. In addition, the gene 39 subunit from the m-AMSA-resistant mutant phage has an altered net charge, strongly indicating that the drug-resistance mutation is within gene 39. Topoisomerase purified from mutant phage-infected Escherichia coli exhibits drug-insensitive DNA relaxation and DNA cleavage activities. Because a single mutation results in both drug-resistant phage growth and a drug-insensitive viral topoisomerase, we conclude that the T4-encoded type II DNA topoisomerase is the physiological target of m-AMSA in phage-infected E. coli.

Documentos Relacionados

• Interaction of the antitumour drug 4'-(9-acridinylamino)-methanesulfon-m-anisidine.HCl (m-AMSA) with nucleic acids.
• Mechanism of antitumor drug action: poisoning of mammalian DNA topoisomerase II on DNA by 4'-(9-acridinylamino)-methanesulfon-m-anisidide.
• Blocked 5'-termini in the fragments of chromosomal DNA produced in cells exposed to the antitumor drug 4'-[(9-acridinyl)-amino]methanesulphon-m-anisidide (mAMSA).
• Limited Genome Expression in Bacteriophage T4-Infected ESCHERICHIA COLI. I. Demonstration of the Effect
• Bacteriophage T4 Mutants Hypersensitive to an Antitumor Agent That Induces Topoisomerase-DNA Cleavage Complexes