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A novel chromatin tether domain controls topoisomerase IIα dynamics and mitotic chromosome formation.

Lane AB, Giménez-Abián JF, Clarke DJ - J. Cell Biol. (2013)

Bottom Line: Here we describe a critical mechanism of chromatin recruitment and exchange that relies on a novel chromatin tether (ChT) domain and mediates interaction with histone H3 and DNA.We show that the ChT domain controls the residence time of Topo IIα on chromatin in mitosis and is necessary for the formation of mitotic chromosomes.Our data suggest that the dynamics of Topo IIα on chromosomes are important for successful mitosis and implicate histone tail posttranslational modifications in regulating Topo IIα.

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Affiliation: Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455.

ABSTRACT
DNA topoisomerase IIα (Topo IIα) is the target of an important class of anticancer drugs, but tumor cells can become resistant by reducing the association of the enzyme with chromosomes. Here we describe a critical mechanism of chromatin recruitment and exchange that relies on a novel chromatin tether (ChT) domain and mediates interaction with histone H3 and DNA. We show that the ChT domain controls the residence time of Topo IIα on chromatin in mitosis and is necessary for the formation of mitotic chromosomes. Our data suggest that the dynamics of Topo IIα on chromosomes are important for successful mitosis and implicate histone tail posttranslational modifications in regulating Topo IIα.

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Immunolocalization of histone H3 isoforms and Topo IIα in mitotic M. muntjak chromosomes.M. muntjak cells stained with anti-GFP antibody to recognize GFP–Topo IIα and costained with antibodies against H3K27me1 (A), H3K27me3 (B), or H3S28p (C). H3K27me1 and H3K27me3 are distributed throughout chromosome arms and partially colocalize with Topo IIα. H3S28p localizes peripherally to Topo IIα. Flattened z stacks are shown. Bar, 10 µm. The full z-series of C is shown in Video 3. DAPI, DNA stain. Images on the right show enlarged segments of the boxed regions (bars, 1.25 µm).
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fig6: Immunolocalization of histone H3 isoforms and Topo IIα in mitotic M. muntjak chromosomes.M. muntjak cells stained with anti-GFP antibody to recognize GFP–Topo IIα and costained with antibodies against H3K27me1 (A), H3K27me3 (B), or H3S28p (C). H3K27me1 and H3K27me3 are distributed throughout chromosome arms and partially colocalize with Topo IIα. H3S28p localizes peripherally to Topo IIα. Flattened z stacks are shown. Bar, 10 µm. The full z-series of C is shown in Video 3. DAPI, DNA stain. Images on the right show enlarged segments of the boxed regions (bars, 1.25 µm).

Mentions: We next asked how H3 isoforms localize relative to Topo IIα. Both K27 methylated isoforms localized with a pattern partially overlapping with the axial core localization of Topo IIα (Fig. 6, A and B), but S28p was clearly excluded from the centrally localized axial core (Fig. 6 C and Video 3). These immunolocalization studies of H3 isoforms are thus consistent with the biochemical analysis of binding between H3 isoforms and the Topo IIα CTR in vitro.


A novel chromatin tether domain controls topoisomerase IIα dynamics and mitotic chromosome formation.

Lane AB, Giménez-Abián JF, Clarke DJ - J. Cell Biol. (2013)

Immunolocalization of histone H3 isoforms and Topo IIα in mitotic M. muntjak chromosomes.M. muntjak cells stained with anti-GFP antibody to recognize GFP–Topo IIα and costained with antibodies against H3K27me1 (A), H3K27me3 (B), or H3S28p (C). H3K27me1 and H3K27me3 are distributed throughout chromosome arms and partially colocalize with Topo IIα. H3S28p localizes peripherally to Topo IIα. Flattened z stacks are shown. Bar, 10 µm. The full z-series of C is shown in Video 3. DAPI, DNA stain. Images on the right show enlarged segments of the boxed regions (bars, 1.25 µm).
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3824022&req=5

fig6: Immunolocalization of histone H3 isoforms and Topo IIα in mitotic M. muntjak chromosomes.M. muntjak cells stained with anti-GFP antibody to recognize GFP–Topo IIα and costained with antibodies against H3K27me1 (A), H3K27me3 (B), or H3S28p (C). H3K27me1 and H3K27me3 are distributed throughout chromosome arms and partially colocalize with Topo IIα. H3S28p localizes peripherally to Topo IIα. Flattened z stacks are shown. Bar, 10 µm. The full z-series of C is shown in Video 3. DAPI, DNA stain. Images on the right show enlarged segments of the boxed regions (bars, 1.25 µm).
Mentions: We next asked how H3 isoforms localize relative to Topo IIα. Both K27 methylated isoforms localized with a pattern partially overlapping with the axial core localization of Topo IIα (Fig. 6, A and B), but S28p was clearly excluded from the centrally localized axial core (Fig. 6 C and Video 3). These immunolocalization studies of H3 isoforms are thus consistent with the biochemical analysis of binding between H3 isoforms and the Topo IIα CTR in vitro.

Bottom Line: Here we describe a critical mechanism of chromatin recruitment and exchange that relies on a novel chromatin tether (ChT) domain and mediates interaction with histone H3 and DNA.We show that the ChT domain controls the residence time of Topo IIα on chromatin in mitosis and is necessary for the formation of mitotic chromosomes.Our data suggest that the dynamics of Topo IIα on chromosomes are important for successful mitosis and implicate histone tail posttranslational modifications in regulating Topo IIα.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455.

ABSTRACT
DNA topoisomerase IIα (Topo IIα) is the target of an important class of anticancer drugs, but tumor cells can become resistant by reducing the association of the enzyme with chromosomes. Here we describe a critical mechanism of chromatin recruitment and exchange that relies on a novel chromatin tether (ChT) domain and mediates interaction with histone H3 and DNA. We show that the ChT domain controls the residence time of Topo IIα on chromatin in mitosis and is necessary for the formation of mitotic chromosomes. Our data suggest that the dynamics of Topo IIα on chromosomes are important for successful mitosis and implicate histone tail posttranslational modifications in regulating Topo IIα.

Show MeSH
Related in: MedlinePlus