Histone H1 and Chromatin Higher-Order Structure

Ramakrishnan, V.

doi:10.1615/critreveukargeneexpr.v7.i3.20

Cited by 109 publications

(63 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the idealized, canonical higher-order 30-nm chromatin fiber (1,5,23), the sedimentation coefficients of fibers with the same nucleosomal repeat length will be a function of their molecular weights (M), fiber lengths (l), and frictional ratios ( f͞fo) as given by the following equation (24):…”

Section: Discussionmentioning

confidence: 99%

“…Structural studies on such bulk material have formed the basis for a variety of models that are proposed to explain the manner in which chains of nucleosomes are packaged into the higher-order state (3)(4)(5). However, the ubiquitous and uniform character for the higher-order chromatin fiber suggested by these models tends to mask the fact that the higherorder chromatin fiber must be an adaptable structure capable of undergoing dynamic structural transitions.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Distinctive higher-order chromatin structure at mammalian centromeres

Gilbert

Allan

2001

Proc. Natl. Acad. Sci. U.S.A.

109

View full text Add to dashboard Cite

The structure of the higher-order chromatin fiber has not been defined in detail. We have used a novel approach based on sucrose gradient centrifugation to compare the conformation of centromeric satellite DNA-containing higher-order chromatin fibers with bulk chromatin fibers obtained from the same mouse fibroblast cells. Our data show that chromatin fibers derived from the centromeric domain of a chromosome exist in a more condensed structure than bulk chromatin whereas pericentromeric chromatin fibers have an intermediate conformation. From the standpoint of current models, our data are interpreted to suggest that satellite chromatin adopts a regular helical conformation compatible with the canonical 30-nm chromatin fiber whereas bulk chromatin fibers appear less regularly folded and are perhaps intermittently interrupted by deformations. This distinctive conformation of the higher-order chromatin fiber in the centromeric domain of the mammalian chromosome could play a role in the formation of heterochromatin and in the determination of centromere identity.W hen fragments of chromatin are isolated from cells and maintained under ionic conditions comparable to those in the nucleus, they are invariably found to be folded into higherorder fibers (1-3). Structural studies on such bulk material have formed the basis for a variety of models that are proposed to explain the manner in which chains of nucleosomes are packaged into the higher-order state (3-5). However, the ubiquitous and uniform character for the higher-order chromatin fiber suggested by these models tends to mask the fact that the higherorder chromatin fiber must be an adaptable structure capable of undergoing dynamic structural transitions. Such properties are required to facilitate the unfolding processes presumed to be essential for gene activation and chromosome replication. On the other hand, the chromatin fiber must also have the capacity to adopt an inert character required to maintain genes in a state of sustained repression and to provide local chromosomal domains with distinctive architectures within which specific chromosomal structures, such as the centromere, can exist (6). Despite these expectations, studies on isolated higher-order fibers have failed to reveal a diversity of structure compatible with the diversity of function. For example, chromatin fibers containing globin gene sequences, isolated from erythroid cells in an activated state, have physical properties equivalent to both bulk and transcriptionally inactive chromatin fibers (7,8). The presence of nucleosome-free hypersensitive sites disrupts the fiber, but between these distinctive regions the chromatin appears to be typically folded. Within the cell, the higher-order chromatin fiber does unfold during transcription, but maintenance of this state is notably transient for the inhibition of polymerase activity leads to a rapid reformation of the folded state (9). Thus, in respect of structural criteria, it appears that chromatin fibers containing active gene sequences cannot...

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Distinctive higher-order chromatin structure at mammalian centromeres

Gilbert

Allan

2001

Proc. Natl. Acad. Sci. U.S.A.

109

View full text Add to dashboard Cite

show abstract

“…Other proteins, including linker histones (H1), high mobility group (HMG) proteins (29), and regulatory proteins such as MeCP2 and Sir3 (30,31), further organize nucleosomes into compacted higher order structures (32). Transcriptionally active and silenced chromatin are distinguished by at least two mechanisms: post-translational modifications of core histones (33)(34)(35) and enrichment for different subtypes of histone H1 (36,37).…”

Section: Based On Its Interactions With Histones and Dna We Propose mentioning

confidence: 99%

Binding of Barrier to Autointegration Factor (BAF) to Histone H3 and Selected Linker Histones Including H1.1

Lee

Wilson

2005

Journal of Biological Chemistry

View full text Add to dashboard Cite

Barrier to autointegration factor (BAF) is an essential conserved double-stranded DNA-binding protein in metazoans. BAF binds directly to LEM domain nuclear proteins (e.g. LAP2, Emerin, and MAN1), lamin A, homeodomain transcription factors, and human immunodeficiency virus type 1-encoded proteins. BAF influences higher order chromatin structure and is required to assemble nuclei. BAF also facilitates retroviral preintegration complex insertion into target DNA in vitro, through unknown mechanisms. We report that BAF binds directly and selectively to linker histone H1.1 (among three subtypes tested) and core histone H3 with affinities of ϳ700 nM and ϳ100 -200 nM, respectively, in vitro and in vivo. Mutations at the bottom and top surfaces of the BAF dimer disrupted or enhanced, respectively, this binding and affected H1 and H3 similarly. Biochemical studies showed that C-terminal residues 108 -215 of histone H1.1 and the N-terminal tail plus helix ␣N in the core of histone H3.1 were each necessary and sufficient to bind BAF. Based on its interactions with histones and DNA, we propose BAF might bind nucleosomes in vivo.

show abstract

“…(43) The ionic-strengthdependent folding of the polynucleosome fiber is highly dominated by the occurrence of linker histones (histone H1) (44) and only a limited extent of folding is reached in its absence. (43) Upon addition of daunomycin to native or to linker histone-depleted chromatin complexes, a biphasic transition in the sedimentation coefficient is observed in both instances, (21) similar to what is observed for the individual nucleosomes.…”

Section: Introductionmentioning

confidence: 99%

The anthracycline antibiotics: antitumor drugs that alter chromatin structure

2004

View full text Add to dashboard Cite

SummaryAnthracycline antibiotics are an important group of antitumor drugs widely used in cancer chemotherapy. However, despite the increasing interest in these chemotherapeutic agents, their mechanism of action is not yet completely understood. Here, we review what is currently known about the molecular mechanisms involved with special emphasis on the interaction of these drugs with chromatin and its constitutive components: DNA and histones. The evidence suggests that one very important component of the activity of these drugs is the result of these manifold interactions that lead to a chromatin unfolding and aggregation. This chromatin structural disruption is likely to interfere with the metabolic processes of DNA (replication and transcription) and it may play an important role in the apoptosis undergone by the cells upon treatment with these drugs.

show abstract

Histone H1 and Chromatin Higher-Order Structure

Cited by 109 publications

References 0 publications

Distinctive higher-order chromatin structure at mammalian centromeres

Distinctive higher-order chromatin structure at mammalian centromeres

Binding of Barrier to Autointegration Factor (BAF) to Histone H3 and Selected Linker Histones Including H1.1

The anthracycline antibiotics: antitumor drugs that alter chromatin structure

Contact Info

Product

Resources

About