title: DNA topoisomerase II as the primary cellular target for salvicine in Saccharomyces cerevisiae.
abstract: OBJECTIVE
  To identify whether DNA topoisomerase II (Topo II) is the primary cellular target of salvicine in Saccharomyces cerevisiae (S cerevisiae) and the action mode of salvicine.
  
  
  METHODS
  The catalytic activity of Topo II was determined by Topo II mediated supercoiled pBR322 relaxation. The effects of salvicine on the growth of four strains of S cerevisiae were assessed by clone forming assay.
  
  
  RESULTS
  Salvicine inhibited Topo II mediated supercoiled pBR322 relaxation in cell-free system. Cytotoxicities of salvicine to parent (JN394) and TOP1 deleted (JN394top1-) yeast cells were at the same level, suggesting Topo I might not be the cellular target of salvicine. Salvicine displayed high activity against JN394t2-1 cells at 25 degrees C, while no growth inhibition was observed at 30 degrees C in the concentration range of interest. Furthermore, JN394t2-5 cells which expressed top2-5 mutant allele were highly resistant to salvicine and etoposide (VP16).
  
  
  CONCLUSIONS
  Topo II was the primary cellular target of salvicine in vivo and salvicine killed yeast cells mainly by trapping the DNA-Topo II cleavage complex. Salvicine and VP16 might share some similar action locus on Topo II.
authors.affiliation: Division of Antitumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: L H
authors.initials: LH
authors.lastname: Meng
authors.forename: X X
authors.initials: XX
authors.lastname: He
authors.forename: J S
authors.initials: JS
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Ding
mesh_terms: D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004250:DNA Topoisomerases, Type II / Q000187:drug effects / Q000378:metabolism*; D005047:Etoposide / Q000494:pharmacology; D009285:Naphthoquinones / Q000494:pharmacology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000254:growth & development*
chemical_list: D009285:Naphthoquinones; C122096:salvicine; D005047:Etoposide; D004250:DNA Topoisomerases, Type II