Cargando…
Dynamics of human DNA topoisomerases IIα and IIβ in living cells
DNA topoisomerase (topo) II catalyses topological genomic changes essential for many DNA metabolic processes. It is also regarded as a structural component of the nuclear matrix in interphase and the mitotic chromosome scaffold. Mammals have two isoforms (α and β) with similar properties in vitro. H...
Autores principales: | , , , , , , , , , |
---|---|
Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
2002
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2173268/ https://www.ncbi.nlm.nih.gov/pubmed/11927602 http://dx.doi.org/10.1083/jcb.200112023 |
_version_ | 1782145173495480320 |
---|---|
author | Christensen, Morten O. Larsen, Morten K. Barthelmes, Hans Ullrich Hock, Robert Andersen, Claus L. Kjeldsen, Eigil Knudsen, Birgitta R. Westergaard, Ole Boege, Fritz Mielke, Christian |
author_facet | Christensen, Morten O. Larsen, Morten K. Barthelmes, Hans Ullrich Hock, Robert Andersen, Claus L. Kjeldsen, Eigil Knudsen, Birgitta R. Westergaard, Ole Boege, Fritz Mielke, Christian |
author_sort | Christensen, Morten O. |
collection | PubMed |
description | DNA topoisomerase (topo) II catalyses topological genomic changes essential for many DNA metabolic processes. It is also regarded as a structural component of the nuclear matrix in interphase and the mitotic chromosome scaffold. Mammals have two isoforms (α and β) with similar properties in vitro. Here, we investigated their properties in living and proliferating cells, stably expressing biofluorescent chimera of the human isozymes. Topo IIα and IIβ behaved similarly in interphase but differently in mitosis, where only topo IIα was chromosome associated to a major part. During interphase, both isozymes joined in nucleolar reassembly and accumulated in nucleoli, which seemed not to involve catalytic DNA turnover because treatment with teniposide (stabilizing covalent catalytic DNA intermediates of topo II) relocated the bulk of the enzymes from the nucleoli to nucleoplasmic granules. Photobleaching revealed that the entire complement of both isozymes was completely mobile and free to exchange between nuclear subcompartments in interphase. In chromosomes, topo IIα was also completely mobile and had a uniform distribution. However, hypotonic cell lysis triggered an axial pattern. These observations suggest that topo II is not an immobile, structural component of the chromosomal scaffold or the interphase karyoskeleton, but rather a dynamic interaction partner of such structures. |
format | Text |
id | pubmed-2173268 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2002 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21732682008-05-01 Dynamics of human DNA topoisomerases IIα and IIβ in living cells Christensen, Morten O. Larsen, Morten K. Barthelmes, Hans Ullrich Hock, Robert Andersen, Claus L. Kjeldsen, Eigil Knudsen, Birgitta R. Westergaard, Ole Boege, Fritz Mielke, Christian J Cell Biol Article DNA topoisomerase (topo) II catalyses topological genomic changes essential for many DNA metabolic processes. It is also regarded as a structural component of the nuclear matrix in interphase and the mitotic chromosome scaffold. Mammals have two isoforms (α and β) with similar properties in vitro. Here, we investigated their properties in living and proliferating cells, stably expressing biofluorescent chimera of the human isozymes. Topo IIα and IIβ behaved similarly in interphase but differently in mitosis, where only topo IIα was chromosome associated to a major part. During interphase, both isozymes joined in nucleolar reassembly and accumulated in nucleoli, which seemed not to involve catalytic DNA turnover because treatment with teniposide (stabilizing covalent catalytic DNA intermediates of topo II) relocated the bulk of the enzymes from the nucleoli to nucleoplasmic granules. Photobleaching revealed that the entire complement of both isozymes was completely mobile and free to exchange between nuclear subcompartments in interphase. In chromosomes, topo IIα was also completely mobile and had a uniform distribution. However, hypotonic cell lysis triggered an axial pattern. These observations suggest that topo II is not an immobile, structural component of the chromosomal scaffold or the interphase karyoskeleton, but rather a dynamic interaction partner of such structures. The Rockefeller University Press 2002-04-01 /pmc/articles/PMC2173268/ /pubmed/11927602 http://dx.doi.org/10.1083/jcb.200112023 Text en Copyright © 2002, The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Article Christensen, Morten O. Larsen, Morten K. Barthelmes, Hans Ullrich Hock, Robert Andersen, Claus L. Kjeldsen, Eigil Knudsen, Birgitta R. Westergaard, Ole Boege, Fritz Mielke, Christian Dynamics of human DNA topoisomerases IIα and IIβ in living cells |
title | Dynamics of human DNA topoisomerases IIα and IIβ in living cells |
title_full | Dynamics of human DNA topoisomerases IIα and IIβ in living cells |
title_fullStr | Dynamics of human DNA topoisomerases IIα and IIβ in living cells |
title_full_unstemmed | Dynamics of human DNA topoisomerases IIα and IIβ in living cells |
title_short | Dynamics of human DNA topoisomerases IIα and IIβ in living cells |
title_sort | dynamics of human dna topoisomerases iiα and iiβ in living cells |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2173268/ https://www.ncbi.nlm.nih.gov/pubmed/11927602 http://dx.doi.org/10.1083/jcb.200112023 |
work_keys_str_mv | AT christensenmorteno dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT larsenmortenk dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT barthelmeshansullrich dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT hockrobert dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT andersenclausl dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT kjeldseneigil dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT knudsenbirgittar dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT westergaardole dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT boegefritz dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells AT mielkechristian dynamicsofhumandnatopoisomerasesiiaandiibinlivingcells |