During both interphase and mitosis, DNA topoisomerase II interacts with DNA as well as RNA through the protein's C-terminal domain

2000 ◽  
Vol 113 (9) ◽  
pp. 1635-1647
Author(s):  
R. Rzepecki ◽  
P.A. Fisher
Keyword(s):  
Nucleic Acid ◽  
Topoisomerase Ii ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Terminal Domain ◽  
Highly Active ◽  
Topo Ii ◽  
Cycle Dependent ◽  
Nucleic Acid Interactions

DNA topoisomerase II (topo II) is thought to be a nuclear enzyme; during interphase most was insoluble and could be recovered in the pellet after centrifugation of cell homogenates at 10,000 g (P-10). Upon entry into mitosis, the majority of topo II did not associate with condensed chromosomes but was apparently solubilized and redistributed throughout the cell. Although two non-chromosomal subfractions of mitotic topo II were defined by centrifugation at 130,000 g, the vast majority (>90%) was recovered in the pellet (P-130). In vivo nucleic acid interactions with topo II were monitored by a recently developed approach of UV-photo-crosslinking, immunoprecipitation and (32)P-labeling. P-10 (interphase) topo II was largely associated with DNA. P-130 (mitotic non-chromosomal) topo II was primarily associated with RNA. These nucleic acid interactions with both interphase and mitotic topo II occurred through the catalytically inert and as yet, poorly understood C-terminal domain of the protein. P-10 topo II was highly active enzymatically. Activity, measured by the ability of topo II to decatenate kDNA minicircles, was reduced by treatment with phosphatase. In contrast, P-130 topo II was relatively inactive but activity could be increased by phosphatase treatment. In vivo, P-130 topo II was more heavily phosphorylated than P-10 topo II; in both, only the C-terminal domain of topo II was detectably modified. Our observations suggest that cell cycle-dependent changes in the distribution, nucleic acid interactions and enzymatic activity of topo II are regulated, at least in part, by phosphorylation/dephosphorylation.

The C-terminal domain of Saccharomyces cerevisiae DNA topoisomerase II

1994 ◽  
Vol 14 (5) ◽  
pp. 3197-3207
Author(s):  
P R Caron ◽  
P Watt ◽  
J C Wang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Localization ◽  
Topoisomerase Ii ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Mutant Proteins ◽  
Terminal Domain ◽  
Catalytically Active

A set of carboxy-terminal deletion mutants of Saccharomyces cerevisiae DNA topoisomerase II were constructed for studying the functions of the carboxyl domain in vitro and in vivo. The wild-type yeast enzyme is a homodimer with 1,429 amino acid residues in each of the two polypeptides; truncation of the C terminus to Ile-1220 has little effect on the function of the enzyme in vitro or in vivo, whereas truncations extending beyond Gln-1138 yield completely inactive proteins. Several mutant enzymes with C termini in between these two residues were found to be catalytically active but unable to complement a top2-4 temperature-sensitive mutation. Immunomicroscopy results suggest that the removal of a nuclear localization signal in the C-terminal domain is likely to contribute to the physiological dysfunction of these proteins; the ability of these mutant proteins to relax supercoiled DNA in vivo shows, however, that at least some of the mutant proteins are present in the nuclei in a catalytically active form. In contrast to the ability of the catalytically active mutant proteins to relax supercoiled intracellular DNA, all mutants that do not complement the temperature-dependent lethality and high frequency of chromosomal nondisjunction of top2-4 were found to lack decatenation activity in vivo. The plausible roles of the DNA topoisomerase II C-terminal domain, in addition to providing a signal for nuclear localization, are discussed in the light of these results.

scholarly journals Cell Cycle-Dependent Control and Roles of DNA Topoisomerase II

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 859 ◽  
Author(s):  
Joyce H. Lee ◽  
James M. Berger
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Topoisomerase Ii ◽  
Type Ii ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Cycle Progression ◽  
Double Stranded Dna ◽  
Topo Ii ◽  
Cycle Dependent

Type II topoisomerases are ubiquitous enzymes in all branches of life that can alter DNA superhelicity and unlink double-stranded DNA segments during processes such as replication and transcription. In cells, type II topoisomerases are particularly useful for their ability to disentangle newly-replicated sister chromosomes. Growing lines of evidence indicate that eukaryotic topoisomerase II (topo II) activity is monitored and regulated throughout the cell cycle. Here, we discuss the various roles of topo II throughout the cell cycle, as well as mechanisms that have been found to govern and/or respond to topo II function and dysfunction. Knowledge of how topo II activity is controlled during cell cycle progression is important for understanding how its misregulation can contribute to genetic instability and how modulatory pathways may be exploited to advance chemotherapeutic development.

scholarly journals The C-terminal domain of Saccharomyces cerevisiae DNA topoisomerase II.

1994 ◽  
Vol 14 (5) ◽  
pp. 3197-3207 ◽  
Author(s):  
P R Caron ◽  
P Watt ◽  
J C Wang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Localization ◽  
Topoisomerase Ii ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Mutant Proteins ◽  
Terminal Domain ◽  
Catalytically Active

A set of carboxy-terminal deletion mutants of Saccharomyces cerevisiae DNA topoisomerase II were constructed for studying the functions of the carboxyl domain in vitro and in vivo. The wild-type yeast enzyme is a homodimer with 1,429 amino acid residues in each of the two polypeptides; truncation of the C terminus to Ile-1220 has little effect on the function of the enzyme in vitro or in vivo, whereas truncations extending beyond Gln-1138 yield completely inactive proteins. Several mutant enzymes with C termini in between these two residues were found to be catalytically active but unable to complement a top2-4 temperature-sensitive mutation. Immunomicroscopy results suggest that the removal of a nuclear localization signal in the C-terminal domain is likely to contribute to the physiological dysfunction of these proteins; the ability of these mutant proteins to relax supercoiled DNA in vivo shows, however, that at least some of the mutant proteins are present in the nuclei in a catalytically active form. In contrast to the ability of the catalytically active mutant proteins to relax supercoiled intracellular DNA, all mutants that do not complement the temperature-dependent lethality and high frequency of chromosomal nondisjunction of top2-4 were found to lack decatenation activity in vivo. The plausible roles of the DNA topoisomerase II C-terminal domain, in addition to providing a signal for nuclear localization, are discussed in the light of these results.

The in vivo distribution and dynamics of DNA topoisomerase II in Drosophila embryonic nuclei and chromosomes

1993 ◽  
Vol 51 ◽  
pp. 74-75
Author(s):  
Jason R. Swedlow ◽  
Neil Osheroff ◽  
Tim Karr ◽  
John W. Sedat ◽  
David A. Agard
Keyword(s):  
Topoisomerase Ii ◽  
Biochemical Characterization ◽  
Developmental Cycle ◽  
Dna Topoisomerase Ii ◽  
Chromosomal Distribution ◽  
Dna Topoisomerase ◽  
Ideal System ◽  
Dnase Treatment

DNA topoisomerase II is an ATP-dependent double-stranded DNA strand-passing enzyme that is necessary for full condensation of chromosomes and for complete segregation of sister chromatids at mitosis in vivo and in vitro. Biochemical characterization of chromosomes or nuclei after extraction with high-salt or detergents and DNAse treatment showed that topoisomerase II was a major component of this remnant, termed the chromosome scaffold. The scaffold has been hypothesized to be the structural backbone of the chromosome, so the localization of topoisomerase II to die scaffold suggested that the enzyme might play a structural role in the chromosome. However, topoisomerase II has not been studied in nuclei or chromosomes in vivo. We have monitored the chromosomal distribution of topoisomerase II in vivo during mitosis in the Drosophila embryo. This embryo forms a multi-nucleated syncytial blastoderm early in its developmental cycle. During this time, the embryonic nuclei synchronously progress through 13 mitotic cycles, so this is an ideal system to follow nuclear and chromosomal dynamics.

scholarly journals Rearrangements of the MLL gene in therapy-related acute myeloid leukemia in patients previously treated with agents targeting DNA- topoisomerase II

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3705-3711 ◽  
Author(s):  
HJ Super ◽  
NR McCabe ◽  
MJ Thirman ◽  
RA Larson ◽  
MM Le Beau ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Topoisomerase Ii ◽  
De Novo ◽  
Chromosome Band ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Mll Gene ◽  
Topo Ii ◽  
Acute Myeloid

Chromosome band 11q23 is frequently involved in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) de novo, as well as in myelodysplastic syndromes (MDS) and lymphoma. Five percent to 15% of patients treated with chemotherapy for a primary neoplasm develop therapy-related AML (t-AML) that may show rearrangements, usually translocations involving band 11q23 or, less often, 21q22. These leukemias develop after a relatively short latent period and often follow the use of drugs that inhibit the activity of DNA-topoisomerase II (topo II). We previously identified a gene, MLL (myeloid-lymphoid leukemia or mixed-lineage leukemia), at 11q23 that is involved in the de novo leukemias. We have studied 17 patients with t-MDS/t-AML, 12 of whom had cytogenetically detectable 11q23 rearrangements. Ten of the 12 t-AML patients had received topo II inhibitors and 9 of these, all with balanced translocations of 11q23, had MLL rearrangements on Southern blot analysis. None of the patients who had not received topo II inhibitors showed an MLL rearrangement. Of the 5 patients lacking 11q23 rearrangements, some of whom had monoblastic features, none had an MLL rearrangement, although 4 had received topo II inhibitors. Our study indicates that the MLL gene rearrangements are similar both in AML that develops de novo and in t-AML. The association of exposure to topo II- reactive chemotherapy with 11q23 rearrangements involving the MLL gene in t-AML suggests that topo II may play a role in the aberrant recombination events that occur in this region both in AML de novo and in t-AML.

scholarly journals The Impact of the Human DNA Topoisomerase II C-Terminal Domain on Activity

PLoS ONE ◽  
2008 ◽  
Vol 3 (3) ◽  
pp. e1754 ◽  
Author(s):  
Emma L. Meczes ◽  
Kathryn L. Gilroy ◽  
Katherine L. West ◽  
Caroline A. Austin
Keyword(s):  
Topoisomerase Ii ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
Terminal Domain ◽  
Human Dna ◽  
The Impact
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