Active heterodimers are formed from human DNA topoisomerase II alpha and II beta isoforms.
AUTOR(ES)
Biersack, H
RESUMO
DNA topoisomerase II is a nuclear enzyme essential for chromosome dynamics and DNA metabolism. In mammalian cells, two genetically and biochemically distinct topoisomerase II forms exist, which are designated topoisomerase II alpha and topoisomerase II beta. In our studies of human topoisomerase II, we have found that a substantial fraction of the enzyme exists as alpha/beta heterodimers in HeLa cells. The ability to form heterodimers was verified when human topoisomerases II alpha and II beta were coexpressed in yeast and investigated in a dimerization assay. Analysis of purified heterodimers shows that these enzymes maintain topoisomerase II specific catalytic activities. The natural existence of an active heterodimeric subclass of topoisomerase II merits attention whenever topoisomerases II alpha and II beta function, localization, and cell cycle regulation are investigated.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=38663Documentos Relacionados
- COUP-TF II homodimers are formed in preference to heterodimers with RXR alpha or TR beta in intact cells.
- Distinct and overlapping ligand specificities of the alpha 3A beta 1 and alpha 6A beta 1 integrins: recognition of laminin isoforms.
- Alpha-DNA VIII: thermodynamic parameters of complexes formed between the oligo-alpha-deoxynucleotides: alpha-d(GGAAGG) and alpha-d(CCTTCC) and their complementary oligo-beta-deoxynucleotides: beta-d(CCTTCC) and beta-d(GGAAGG) are different.
- Intradimerically tethered DNA topoisomerase II is catalytically active in DNA transport.
- Isolation of genetic suppressor elements, inducing resistance to topoisomerase II-interactive cytotoxic drugs, from human topoisomerase II cDNA.