Preferential, cooperative binding of DNA topoisomerase II to scaffold-associated regions.

Adachi, Yasuhisa; Käs, Emmanuel; Laemmli, Ulrich Karl

doi:10.1002/j.1460-2075.1989.tb08582.x

Cited by 304 publications

(213 citation statements)

References 45 publications

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“…Besides its enzymatic activity that creates transient double-strand breaks in duplex DNA and passes DNA strands through one another, the protein has been shown to interact with the MAR and SAR elements [8]. Thus, topo 11 is thought to have catalytic as well as structural functions.…”

Section: Introductionmentioning

confidence: 99%

DNA Topoisomerase II Is Not Detectable on Lampbrush Chromosomes but Enriched in the Amplified Nucleoli of Xenopus Oocytes

Fischer

Hock

Scheer

1993

Experimental Cell Research

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In somatic cells DNA topoisomerase 11 (topo 11) is thought to be involved in the domain organization of the genome by anchoring the basis of chromatin loops to a chromosomal scaffold. Lampbrush chromosomes of amphibian oocytes directly display this radial loop organization in cytological preparations. In order to find out whether topo 11 may play a role in the organization of these meiotic chromosomes, we performed immunofluorescence studies using antibodies against Xenopus topo 11. Our results indicate that topo 11 is apparently absent from lampbrush chromosomes and is hence unlikely to act as a "fastener" of the numerous lateral chromosomalloops. Topo 11 was, however, enriched in the amplified nucleoli of Xenopus oocytes. © 1993 Academic Press, Inc. INTRODUCTIONThe chromatin fiber of eukaryotic cells is folded into a series of loops or domains which are stabilized by a structural framework called nuclear matrix or chromosomal scaffold. The loops are thought to be anchored at their base to the matrix or scaffold via specific attachment sites, the so-called matrix or scaffold attachment regions (MARs or SARs). Loop length is variable, ranging from 5 to 200 kbp of DNA [for reviews see 1, 2]. Unfortunately, the chromatin loop structures cannot be directly visualized in interphase nuclei with cytological methods because the chromatin strands are highly entangled.The situation is different for amphibian lampbrush chromosomes which can be readily examined under almost native conditions by light microscopy [3]. The structural organization of these meiotic chromosomes exhibits a striking similarity to the loop model described above. Each lampbrush chromosome consists of a chromosomal axis from which numerous loops radiate laterally. The axis represents a linear array of chromo-1 To whom correspondence and reprint requests should be addressed at Zoologie I, Biozentrum Am Hubland, D-97074 Wiirzburg, Germany. Fax: 0049 931 888 4252. 255 meres containing highly condensed chromatin, while the lateral loops consist of decondensed, transcriptionally active chromatin covered with numerous nascent transcripts. Because lampbrush chromosome architecture resembles so closely the proposed organization of somatic interphase chromatin and mitotic chromosomes, it is tempting to speculate that the same molecular components might be involved in the maintenance of chromatin loops.One of the best characterized components of the chromosomal scaffold is DNA topoisomerase 11 (topo 11) [4][5][6][7]. Besides its enzymatic activity that creates transient double-strand breaks in duplex DNA and passes DNA strands through one another, the protein has been shown to interact with the MAR and SAR elements [8]. Thus, topo 11 is thought to have catalytic as well as structural functions. Topo 11 is not only associated with the scaffold of mitotic chromosomes but also the cores and centromeric regions of spermatocyte-derived meiotic chromosomes [9]. Recently Luke and Bogenhagen identified by biochemical means topo 11 in the germinal vesicles of Xenopus o...

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Section: Introductionmentioning

confidence: 99%

DNA Topoisomerase II Is Not Detectable on Lampbrush Chromosomes but Enriched in the Amplified Nucleoli of Xenopus Oocytes

Fischer

Hock

Scheer

1993

Experimental Cell Research

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“…Transient transfections such as these do not represent the physiological scenario where histone proteins and architectural elements of tertiary structure, such as scaffold attachment regions (SARs) are involved. An indicator of an SAR is the presence of AT-rich elements, 35,36 and such a region is located 5Ј of −1025hLuc. It is possible that complex secondary structure resulting from internal homology is formed at this region, preventing TF ingress, and thus transcriptional activation.…”

Section: Discussionmentioning

confidence: 99%

Design of a muscle cell-specific expression vector utilising human vascular smooth muscle α-actin regulatory elements

Chen

et al. 1999

Gene Ther

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“…Earnshaw et al [11] and Adachi et al [12] indicated that Topoisomerase II is a component of the chromosome scaffold and nuclear matrix. Nakayasu and Berezney [13] identified, with two dimensional IEF/SDS-PAGE and immunobloting, laminins A, B, C, nucleolar protein B23 and some matrins as components of the nuclear matrix in a broad sense.…”

Section: Discussionmentioning

confidence: 99%

“…The main component of nuclear matrix and chromosome scaffold is nonhistone proteins [1][2][3][4], [10]. Although many biochemical and immunocytochemical analyses have been conducted concerning protein composition of the nuclear matrix and chromosome scaffold, only a few proteins (such as topoisomerase II) have been identified [11][12][13][14][15][16]. Some previous biochemical analyses indicated that a polypeptide of about 37 kD, which is equivalent to tropomyosin in molecular weight, existed in the nuclear matrix and chromosome scaffold [15], [17][18][19][20] and this polypeptide might represent tropomyosin [19].…”

Section: Introductionmentioning

confidence: 99%

Tropomyosin is localized in the nuclear matrix and chromosome scaffold of physarum polycephalum

et al. 1999

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The nuclei and chromosomes were isolated from plasmodia of Physarum polycephalum. The nuclear matrix and chromosome scaffold were obtained after the DNA and most of the proteins were extracted with DNase I and 2 M NaCl. SDS-PAGE analyses revealed that the nuclear matrix and chromosome scaffold contained a 37 kD polypeptide which is equivalent to tropomyosin in molecular weight. Immunofluorescence observations upon slide preparations labeled with anti-tropomyosin antibody showed that the nuclear matrix and chromosome scaffold emanated bright fluorescence, suggesting the presence of the antigen in them. Immunodotting results confirmed the presence of tropomyosin in the nuclear matrix and chromosome scaffold. Immunoelectron microscopic observations further demonstrated that tropomyosin was dispersively distributed in the interphase nuclei and metaphase chromosomes.

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Preferential, cooperative binding of DNA topoisomerase II to scaffold-associated regions.

Cited by 304 publications

References 45 publications

DNA Topoisomerase II Is Not Detectable on Lampbrush Chromosomes but Enriched in the Amplified Nucleoli of Xenopus Oocytes

DNA Topoisomerase II Is Not Detectable on Lampbrush Chromosomes but Enriched in the Amplified Nucleoli of Xenopus Oocytes

Design of a muscle cell-specific expression vector utilising human vascular smooth muscle α-actin regulatory elements

Tropomyosin is localized in the nuclear matrix and chromosome scaffold of physarum polycephalum

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