title: Analysis of phosphorylation level of DNA topoisomerase-ii-alpha and topoisomerase-ii-Beta in human hela-cells.
abstract: We have studied the phosphorylation of DNA topoisomerases II in HeLa cells focusing on the beta isoform of the enzyme which is very difficult to analyze because of its instability. In proliferating cells, we observed that both the a and beta isozymes are labeled after cell incubation with (32)p. The phosphorylation of beta enzyme occurs to a low extent, thus reflecting the expression of topoisomerases II during cell cycle. In cells treated with etoposide, the activity of topoisomerase II is inhibited and the level of phosphorylation decreases, suggesting a possible cooperation between this modification and drug response.
authors.affiliation: CNR,IST GENET BIOCHIM & EVOLUZIONIST,I-27100 PAVIA,ITALY.
authors.forename: R
authors.initials: R
authors.lastname: Bernardi
authors.forename: C
authors.initials: C
authors.lastname: Negri
authors.forename: M
authors.initials: M
authors.lastname: Donzelli
authors.forename: F
authors.initials: F
authors.lastname: Guano
authors.forename: A
authors.initials: A
authors.lastname: Scovassi