Presence of histone H1 on an active Balbiani ring gene

Ericsson, Christer; Grossbach, Ulrich; Björkroth, Birgitta; Daneholt, Bertil

doi:10.1016/0092-8674(90)90717-s

Cited by 98 publications

(60 citation statements)

References 55 publications

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“…Weintraub put forward the proposal for an altered binding of H1 to DNA that destabilised the higher-order chromatin structure [46]. Recent reports showed the presence of H I on the active hsp70 genes in Drosophilu [41], as well as on the extended transcribed DNA of Balbiani-ring genes in the salivary glands of Chironomus [47]. The present investigation extends these data for the ribosomal genes in Xenopus.…”

Section: Discussionsupporting

confidence: 71%

Binding of histones to Xenopus laevis ribosomal genes with different levels of expression

Dimitrov

Tateossyan

Stefanovsky

et al. 1992

European Journal of Biochemistry

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The association of ribosomal RNA genes with histones as a function of their expression has been studied in Xenopus luevis erythrocytes, where the genes are silent, and tadpoles at stage 40, where these genes are actively transcribed. Isolated nuclei were either treated with formaldehyde or irradiated with an ultraviolet laser to cross-link proteins to DNA. The covalently linked protein-DNA complexes were purified by centrifugation through CsCl and immunoprecipitated with antibodies against H1, H2A and H4. DNA from the precipitated complexes was analysed for the presence of ribosomal DNA sequences by hybridization to specific probes. The actively transcribed ribosomal genes from X . luevis embryos are associated with H1, H2A and H4 as are the non-transcribed genes in the erythrocytes.In the light of the progress made in understanding the structure of the nucleosome as the basic unit of chromatin, surprisingly little is known about its behavior during transcription. It is not presently known whether the nucleosomes impede the movement of transcribing RNA polymerases along DNA; nucleosomes have been identified on both repressed and some active genes (for reviews see 11 -3). It is not even known whether the histones interfere at all with the transcriptional machinery. Whilst the possibility for transient unfolding of nucleosomes immediately engaged in transcription offers some explanation for the contradictory results concerning the nucleosomal organization of active genes, whether such an unfolding is accompanied by dissociation of histones or whether they remain bound to DNA is not clear.Extensive studies in this respect have been focused on the genes for ribosomal DNA. Electron-microscopic visualization of ribosomal genes have revealed non-beaded chromatin fibers within active transcriptional units [4-81, in some cases indistinguishable from naked DNA [6, 81. It has been argued that the nucleolar chromatin from X . luevis oocytes is associated with a few proteins other than those involved in transcription [6]. Other investigations, however, contradict such a conclusion. The presence of organized, histone-containing particles in transcribed ribosomal chromatin was implied mainly from biochemical studies [9 -151. Consistent with such a view is the evidence from yeast that the nucleosome loss does not have a gcneral effect on transcription by all three polymerases [16,17]. Furthermore, data have been presented for a different nucleosome structure of transcribed ribosomal DNA chromatin from Physurum [12-141; studies on the exposure of the sulfhydryl group of histone H3 in these nucleosomes raised the possibility of nucleosome unfolding during transcription Correspondence to I. G. Pashev, Institute of Molecular Biology, Bulgarian Academy of Sciences, BG-1113 Sofia, Bulgaria without dissociation of histones from DNA [13]. Recently, two groups addressed these questions by investigating the effect on transcription of a single-positioned nucleosome on short linear DNA [18,19]. They showed that the prokaryotic SP6 polymera...

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Section: Discussionsupporting

confidence: 71%

Binding of histones to Xenopus laevis ribosomal genes with different levels of expression

Dimitrov

Tateossyan

Stefanovsky

et al. 1992

European Journal of Biochemistry

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“…H1 has been regarded as having an essentially repressive role in transcription (5) and might be involved in controlling activity of individual genes (6 -8). Linker histones are present in inactive and actively transcribing chromatins (9,10), but in the latter they seem to be reduced in their amount and bind in a different manner (11)(12)(13).…”

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confidence: 99%

Histone H1 and chromatin interactions in human fibroblast nuclei after H1 depletion and reconstitution with H1 subfractions

et al. 2004

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Background:Linker histones constitute a family of lysinerich proteins associated with nucleosome core particles and linker DNA in eukaryotic chromatin. In permeabilized cells, they can be extracted from nuclei by using salt concentration in the range of 0.3 to 0.7 M. Although other nuclear proteins are also extracted at 0.7 M salt, the remaining nucleus represents a template that is relatively intact. Methods: A cytochemical method was used to study the affinity of reconstituted linker histones for chromatin in situ in cultured human fibroblasts. We also investigated their ability to condense chromatin by using DNA-specific osmium ammine staining for electron microscopy. Results: Permeabilized and H1-depleted fibroblast nuclei were suitable for the study of linker histone-chromatin

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“…Some studies, using immunoprecipitation and hybridization of cross-linked chromatin fragments, have suggested that H1 is present in active chromatin, although in lower than stoichiometric amounts [30][31][32][33][34]. This partial depletion was attributed not to lower stoichiometric amounts but to the changed mode of interaction of H1 with active nucleosomes [34].…”

Section: Discussionmentioning

confidence: 99%

Structure of active chromatin: isolation and characterization of transcriptionally active chromatin from rat liver

Tikoo

Gupta

Hamid

et al. 1997

Biochemical Journal

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Rat liver nuclei were isolated in low-ionic-strength buffer in the absence of bi- and multi-valent cations. Digestion of these nuclei by endogenous nuclease, micrococcal nuclease and DNase I revealed that a minor chromatin fraction was preferentially digested into poly- and oligo-nucleosomes. Southern blot hybridization with various active gene probes confirmed that these chromatin fragments represent coding and 5ƀ upstream regions of transcriptionally active chromatin. Active chromatin fragments were released selectively into the medium, with inactive chromatin remaining inside the nuclei, under the above ionic conditions. The inclusion of bivalent cations during the digestion of nuclei reversed the solubility behaviour of active chromatin. Rearrangement and exchange of histone H1 between chromatin fragments was prevented by using low-salt conditions in all steps in the absence of bivalent cations. All histones, including H1, were present in stoichiometric amounts in this active chromatin fraction. Active nucleosomes showed a lower electrophoretic mobility than bulk nucleosomes in an acrylamide/agarose composite gel in the absence of Mg2+, but were selectively bound to the gel in the presence of this ion.

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Presence of histone H1 on an active Balbiani ring gene

Cited by 98 publications

References 55 publications

Binding of histones to Xenopus laevis ribosomal genes with different levels of expression

Binding of histones to Xenopus laevis ribosomal genes with different levels of expression

Histone H1 and chromatin interactions in human fibroblast nuclei after H1 depletion and reconstitution with H1 subfractions

Structure of active chromatin: isolation and characterization of transcriptionally active chromatin from rat liver

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