caa a22 4500 477089348 CHVBK 20180405111512.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF02265053 doi (NATIONALLICENCE)springer-10.1007/BF02265053 Organization of DNA topoisomerase II isotypes during the cell cycle of human lymphocytes and HeLa cells [Elektronische Daten] [N. Chaly, X. Chen, J. Dentry, D. Brown] We have monitored the organization of DNA topoisomerase II (Topo II) in relation to chromatin disaggregation during mitogen stimulation of lymphocytes and to the mitotic chromosome condensation cycle by immunofluorescence microscopy with isozyme-specific antibodies. Labelling for both Topo IIα and Topo IIβ was diffusely nucleoplasmic and non-nucleolar in resting lymphocytes and the pattern changed little during stimulation. Topo IIα labelling intensity increased in parallel with the extent of cell stimulation, but a fraction of fully stimulated cells was labelled very brightly. Topo IIβ labelling intensity was also greater in stimulated cells, but all partially and fully stimulated cells were labelled at the same, higher, intensity. In addition, anti-Topo IIβ detected a few small spots within nucleoli of stimulated cells that coincided with regions containing fibrillarin. In lymphocytes and HeLa, chromosome association of Topo IIα began in prophase and lasted throughout mitosis. In contrast, Topo IIβ stayed nucleoplasmic in prophase, was diffusely cytoplasmic during mitosis, and was first detected post-mitotically in nuclel with decondensing chromosomes and a reformed nuclear envelope. The results are consistent with a role for Topo IIα, but not for Topo IIβ, in mitotic chromosome condensation, and indicate that the isotypes may play independent roles in the reorganization of chromatin structure during lymphocyte mitogenic activation. Rapid Science Publishers, 1996 cell cycle nationallicence HeLa nationallicence immunolocalization nationallicence lymphocytes nationallicence Topo II isotypes nationallicence Chaly N. Department of Biology, ELBA, Carleton University, 1125 Colonel By Drive, KIS 5B6, Ottawa, ON, Canada aut Chen X. Department of Biology, ELBA, Carleton University, 1125 Colonel By Drive, KIS 5B6, Ottawa, ON, Canada aut Dentry J. Department of Biology, University of Ottawa, Ottawa, ON, Canada aut Brown D. Department of Biology, University of Ottawa, Ottawa, ON, Canada aut Chromosome Research Kluwer Academic Publishers 4/6(1996-09-01), 457-466 0967-3849 4:6<457 1996 4 10577 https://doi.org/10.1007/BF02265053 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02265053 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chaly N. Department of Biology, ELBA, Carleton University, 1125 Colonel By Drive, KIS 5B6, Ottawa, ON, Canada aut NATIONALLICENCE 700 1- Chen X. Department of Biology, ELBA, Carleton University, 1125 Colonel By Drive, KIS 5B6, Ottawa, ON, Canada aut NATIONALLICENCE 700 1- Dentry J. Department of Biology, University of Ottawa, Ottawa, ON, Canada aut NATIONALLICENCE 700 1- Brown D. Department of Biology, University of Ottawa, Ottawa, ON, Canada aut NATIONALLICENCE 773 0- Chromosome Research Kluwer Academic Publishers 4/6(1996-09-01), 457-466 0967-3849 4:6<457 1996 4 10577 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer