Characterization of cDNA encoding the mouse DNA topoisomerase II that can complement the budding yeast<i>top2</i>mutation

Adachi, Noritaka; Miyaike, Mitsuko; Ikeda, Hideo; Kikuchi, Akihiko

doi:10.1093/nar/20.20.5297

Cited by 32 publications

(25 citation statements)

References 39 publications

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“…The findings on complementation are in agreement with earlier studies, in which wild-type S. cerevisiae and a recombinant form of human topoisomerase II␣ having the N-terminal part substituted by the equivalent sequence of the yeast enzyme were able to sustain mitotic growth in a top2 temperature-sensitive strain. Our observation adds to the general conclusion that topoisomerase II enzymes from a wide variety of eukaryotic origins are functionally interchangeable (2,17,57,61,68).…”

Section: Resultssupporting

confidence: 55%

Analysis of Functional Domain Organization in DNA Topoisomerase II from Humans and Saccharomyces cerevisiae

Jensen

Andersen

Kjeldsen

et al. 1996

Molecular and Cellular Biology

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The functional domain structure of human DNA topoisomerase II␣ and Saccharomyces cerevisiae DNA topoisomerase II was studied by investigating the abilities of insertion and deletion mutant enzymes to support mitotic growth and catalyze transitions in DNA topology in vitro. Alignment of the human topoisomerase II␣ and S. cerevisiae topoisomerase II sequences defined 13 conserved regions separated by less conserved or differently spaced sequences. The spatial tolerance of the spacer regions was addressed by insertion of linkers. The importance of the conserved regions was assessed through deletion of individual domains. We found that the exact spacing between most of the conserved domains is noncritical, as insertions in the spacer regions were tolerated with no influence on complementation ability. All conserved domains, however, are essential for sustained mitotic growth of S. cerevisiae and for enzymatic activity in vitro. A series of topoisomerase II carboxy-terminal truncations were investigated with respect to the ability to support viability, cellular localization, and enzymatic properties. The analysis showed that the divergent carboxy-terminal region of human topoisomerase II␣ is dispensable for catalytic activity but contains elements that specifically locate the protein to the nucleus.Eukaryotic DNA topoisomerase II is an abundant nuclear enzyme involved in regulating the conversion of DNA between different topological isoforms (42, 60). It fulfills essential functions in DNA replication (41, 53) and chromosome segregation during both mitosis (26, 27) and meiosis (46), and it is thought to play a key role in certain types of DNA recombination events (8,10,22,30,48). The enzyme has furthermore been suggested to constitute a component of nuclear scaffold structures (3, 23), where it may be involved in chromosome condensation (4, 58) and decondensation (45).Topoisomerase II binds to DNA as a dimer and cleaves its DNA substrate with a 4-bp stagger (40, 60) at sites with loosely defined sequences (54). Upon DNA cleavage, each subunit of topoisomerase II becomes transiently ligated to the 5Ј ends of the respective DNA strands through an O 4 -phosphotyrosine bond involving a tyrosine residue in the active site of the protein (7, 36). Catalytic activity is ATP dependent, and it is performed by passing one intact DNA helix through the enzyme-mediated double-stranded DNA break, followed by rejoining of the DNA strands (42).Although the mechanics of topoisomerase II function have been characterized in great detail, little information has emerged about the functional organization of the enzyme. Proteolysis studies on purified topoisomerase II from Saccharomyces cerevisiae (35), Schizosaccharomyces pombe (50), Drosophila melanogaster (34), and humans (9) suggest that the enzyme is composed of three major structural domains, of which two are constituted by the conserved N-terminal and central parts of the protein and a third is constituted by the highly divergent C-terminal region.The fragment originating from the N-...

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Section: Resultssupporting

confidence: 55%

Analysis of Functional Domain Organization in DNA Topoisomerase II from Humans and Saccharomyces cerevisiae

Jensen

Andersen

Kjeldsen

et al. 1996

Molecular and Cellular Biology

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“…The PCR primers mtopo 4273 (5Ј-GACCGTGGGAGTGAAGAAGACAGCAAC-3Ј) and mtopo 4594 (5Ј-AATTGGCTTCCTCGCCCGGTCAGATTTGGCT-3Ј) were based on the sequence of mouse topoisomerase II␣ cDNA (22) and were used to amplify nucleotides 4273-4594 of the topoisomerase II␣ cDNA. The PCR primers mE2F 877 (5Ј-CTCCTGAGACCCAACTA-CAAGCTGTGGA-3Ј) and mE2F 1320 (5Ј-CCTCCTCGAGACCAAAGT-GATAGTCAAG-3Ј) were based on the mouse E2F1 sequence (23) and were used to amplify nucleotides 877-1320 of the E2F1 cDNA.…”

Section: Methodsmentioning

confidence: 99%

Stable Expression of a Dominant Negative Mutant of CCAAT Binding Factor/NF-Y in Mouse Fibroblast Cells Resulting in Retardation of Cell Growth and Inhibition of Transcription of Various Cellular Genes

Maity

2000

Journal of Biological Chemistry

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Section: Dna Topomentioning

confidence: 99%

“…This residue is a major site of phosphorylation in several different human cell lines studied (29). Of the other two sites, serine 1376 is conserved in mouse and rat topo II␣, but its flanking sequence is not, while threonine 1342 is not conserved, being replaced by an aspartate in the rodent enzymes (32,33).In this study, we have investigated the role played by casein kinase II in regulating the activity of human topo II␣. We show that co-incubation of topo II␣ with casein kinase II strongly influences the ability of topo II␣ to decatenate kinetoplast DNA.…”

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confidence: 99%

Casein Kinase II Stabilizes the Activity of Human Topoisomerase IIα in a Phosphorylation-independent Manner

Redwood

Davies

Wells³

et al. 1998

Journal of Biological Chemistry

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Previous reports have indicated that topoisomerase II (topo II) co-purifies with and is a substrate for casein kinase II. We have carried out a detailed study of the effect that purified casein kinase II has on the activity of purified recombinant human topo II␣. Co-incubation of topo II␣ and casein kinase II led to an apparent activation of the topo II␣; however, in experiments in which topo II␣ was preincubated at 37°C with or without native casein kinase II prior to assaying for decatenation activity, it emerged that the kinase was exerting its "activating" function via a decrease in the rate of topo II␣ enzyme inactivation during the incubation period. This stabilization of topo II␣ by casein kinase II was ATP-independent and was observed in both mutated and truncated derivatives of topo II␣ lacking the major casein kinase II phospho-acceptor sites, indicating the lack of a requirement for phosphorylation. Consistent with a nonenzymatic role for casein kinase II, stoichiometric quantities of kinase were required for topo II␣ stabilization. These data indicate that casein kinase II plays a significant role in regulating human topo II␣ protein action via stabilization against thermal inactivation. DNA topo1 II is a ubiquitous and structurally conserved enzyme required for many different aspects of DNA metabolism (reviewed in Refs. 1 an 2). Studies in bacterial and lower eukaryotic species have revealed that topo II is required for cell viability due to an essential role in the segregation of newly replicated chromosomes during cell division (3-7). During replication, sister DNA molecules become knotted and catenated as a consequence of the difficulties inherent in the unwinding and copying of a double-stranded, helical nucleic acid structure (reviewed in Ref. 8). In eukaryotes, topo II catalyzes the disentanglement of sister chromatids and hence permits their faithful segregation during mitosis. Studies on yeast temperaturesensitive top2 mutants have shown that both chromosome hypercondensation and sister chromatid segregation are dependent upon functional topo II, and that in the absence of topo II chromosomes break or nondisjoin as the mitotic spindle attempts to pull apart the still interlinked DNA molecules (3-8).In mammalian cells, but not in yeasts, topo II exists as two closely related isoforms designated ␣ (170-kDa form) and ␤ (180-kDa form) (9 -13). The respective roles of the two isoforms are not known currently, although several differences in their activities/regulation have been noted. For example, the ␣ isoform is a strict proliferation marker in vitro and in vivo and is expressed at a high level in each cell cycle during the period just prior to cell division (14 -17). This isoform is tightly associated with condensed chromatin during metaphase. In contrast, topo II␤ is ubiquitously expressed in human tissues and is apparently excluded from chromosomes around the time of mitotic chromosome condensation, although it is found in the nucleoplasm during interphase (14 -18).Topo II is a phosphoprotei...

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Characterization of cDNA encoding the mouse DNA topoisomerase II that can complement the budding yeasttop2mutation

Cited by 32 publications

References 39 publications

Analysis of Functional Domain Organization in DNA Topoisomerase II from Humans and Saccharomyces cerevisiae

Analysis of Functional Domain Organization in DNA Topoisomerase II from Humans and Saccharomyces cerevisiae

Stable Expression of a Dominant Negative Mutant of CCAAT Binding Factor/NF-Y in Mouse Fibroblast Cells Resulting in Retardation of Cell Growth and Inhibition of Transcription of Various Cellular Genes

Casein Kinase II Stabilizes the Activity of Human Topoisomerase IIα in a Phosphorylation-independent Manner

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