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At least 343 records · Page 19Linked to original sources
PubMed2006

Arabidopsis thaliana histone deacetylase 1 (AtHD1) is localized in euchromatic regions and demonstrates histone deacetylase activity in vitro.

Arabidopsis thaliana histone deacetylase 1 (AtHD1 or AtHDA19), a homolog of yeast RPD3, is a global regulator of many physiological and developmental processes in plants. In spite of the genetic evidence for a role of AtHD1 in plant gene regulation and development, the biochemical and cellular properties of AtHD1 are poorly understood. Here we report cellular localization patterns of AtHD1 in vivo and histone deacetylase activity in vitro. The transient and stable expression of a green fluorescent protein (GFP)-tagged AtHD1 in onion cells and in roots, seeds and leaves of the transgenic Arabidopsis, respectively, revealed that AtHD1 is localized in the nucleus presumably in the euchromatic regions and excluded from the nucleolus. The localization patterns of AtHD1 are different from those of AtHD2 and AtHDA6 that are involved in nucleolus formation and silencing of transgenes and repeated DNA elements, respectively. In addition, a histone deacetylase activity assay showed that the recombinant AtHD1 produced in bacteria demonstrated a specific histone deacetylase activity in vitro. The data suggest that AtHD1 is a nuclear protein and possesses histone deacetylase activities responsible for global transcriptional regulation important to plant growth and development.

Acetylation↗
PubMed1972

Histone acetylation and hormone action. Early effects of oestradiol-17beta on histone acetylation in rat uterus.

The effect of oestradiol treatment on the acetylation of histones of the immature rat uterus has been studied. A 10mug dose of oestradiol causes a 70% increase at 5min and a 140% increase at 10min after administration in the labelling of the histone fraction F2+F3. No effect of oestradiol is seen on the labelling of histones F1 or acidic non-histone chromatin proteins. The oestradiol stimulation is seen in animals pretreated with either cycloheximide or actinomycin D. The stimulation of labelling caused by oestradiol is completely abolished by pretreatment of the animals with the anti-oestrogen, nafoxidine. The stimulation is given by lower doses of oestradiol, by stilboestrol and oestriol, but is not given by testosterone. These results suggest that stimulation of histone acetylation in the uterus is the earliest known effect of the hormone on its target tissue.

Acetates↗
PubMed1973

Histone acetylation and hormone action. Early effects of aldosterone on histone acetylation in rat kidney.

Histone acetylation in the kidney of the adrenalectomized rat was increased 5 min after a physiological dose of aldosterone. The increase was exclusively in the histone F2a1. The increase in histone acetylation was given by 9alpha-fluorocortisol, deoxycorticosterone and cortisol, but not by progesterone. The increase in histone acetylation was abolished by prior treatment of the animals with the anti-mineralocorticoid agent, SC14266 [potassium 3-(3-oxo-17beta-hydroxy-4,6-androstadien-17-yl) propionate]; the basal degree of histone acetylation was unaffected. Pretreatment of the animals with actinomycin D or cyclo-heximide did not affect the stimulation, showing the stimulation was not due to increased synthesis of enzyme.

Acetates↗
PubMed1980

Leader sequences of Strongylocentrotus purpuratus histone mRNAs start at a unique heptanucleotide common to all five histone genes.

We have determined the sequence of the untranslated leader nucleotides of all five histone mRNAs from Strongylocentrotus purpuratus by the dideoxy chain termination method. Total polysomal RNA from sea urchin embryos was used as a substrate for cDNA synthesis primed by specific DNA restriction fragments. Each of the primers was derived from the 5'-terminal part of the coding region for a different histone protein. The five histone mRNA leader sequences are different in length and primary structure. The 5' termini of all five histone mRNAs coincide with the unique heptanucleotide Py-Py-A-T-T-C-Pu in genomic DNA. This sequence, which defines the start of the individual histone mRNAs, is preceded by the A+T-rich octanucleotide identified in front of all eukaryotic structural genes where sequences have been determined to date.

Animals↗
PubMed2003

Preferential binding of the histone (H3-H4)2 tetramer by NAP1 is mediated by the amino-terminal histone tails.

The yeast nucleosome assembly protein 1 (yNAP1) participates in many diverse activities, such as the assembly of newly synthesized DNA into chromatin and the rearrangement of nucleosomes during transcriptional activation. yNAP1 does not require ATP hydrolysis to perform these functions and is a valuable tool for in vitro chromatin assembly. Using recombinant histone complexes, we show that yNAP1 has a preference for binding the (H3-H4)2 tetramer over the (H2A-H2B) dimer. We find that the loss of the histone tails abrogates this preference for H3 and H4, and we demonstrate a direct interaction between yNAP1 and the amino-terminal tails of H3 and H4. yNAP1 binds to one histone fold domain, thus specifying the stoichiometry of the complexes formed with the histone dimer and tetramer. Finally, we provide evidence that the acidic carboxyl-terminal region of yNAP1, although dispensable for nucleosome assembly in vitro, contributes to binding via structure-independent electrostatic interactions. Our results are consistent with recent mechanistic investigations of NAP1 and expand our understanding of the histone chaperone family of assembly factors.

Animals↗
PubMed2005

Binding of barrier to autointegration factor (BAF) to histone H3 and selected linker histones including H1.1.

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 approximately 700 nm and approximately 100-200 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 alphaN 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.

Amino Acid Sequence↗
PubMed1994

Remodeling sperm chromatin in Xenopus laevis egg extracts: the role of core histone phosphorylation and linker histone B4 in chromatin assembly.

We find that the remodeling of the condensed Xenopus laevis sperm nucleus into the paternal pronucleus in egg extracts is associated with phosphorylation of the core histones H2A, H2A.X and H4, and uptake of a linker histone B4 and a HMG 2 protein. Histone B4 is required for the assembly of chromatosome structures in the pronucleus. However neither B4 nor core histone phosphorylation are required for the assembly of spaced nucleosomal arrays. We suggest that the spacing of nucleosomal arrays is determined by interaction between adjacent histone octamers under physiological assembly conditions.

Animals↗
PubMed1996

Organization of the chicken histone genes in a major gene cluster and generation of an almost complete set of the core histone protein sequences.

We present a detailed picture of the disposition of the histone genes in the chicken genome and an almost complete set of the core histone protein sequences. Thirty-nine histone genes, six H1, nine H2A, eight H2B, eight H3 and eight H4, were located within a histone gene cluster of 110 kb, which was covered by five cosmid clones and two lambda clones. Results of our sequence analyses, together with those reported previously, generated a set of the core histone amino acid sequences as follows: three H2A variants, four H2B variants, two H3 variants and an H4 protein.

Amino Acid Sequence↗
PubMed2004

Adaptive evolution of the histone fold domain in centromeric histones.

Centromeric DNA, being highly repetitive, has been refractory to molecular analysis. However, centromeric structural proteins are encoded by single-copy genes, and these can be analyzed by using standard phylogenetic tools. The centromere-specific histone, CenH3, replaces histone H3 in centromeric nucleosomes, and is required for the proper distribution of chromosomes during cell division. Whereas histone H3s are nearly identical between species, CenH3s are divergent, with an N-terminal tail that is highly variable in length and sequence. Both the N-terminal tail and histone fold domain (HFD) are subject to adaptive evolution in Drosophila. Similarly, comparisons between Arabidopsis thaliana and Arabidopsis arenosa detected adaptive evolution, but only in the N-terminal tail. We have extended our evolutionary analyses of CenH3s to other members of the Brassicaceae, which allowed the detection of positive selection in both the N-terminal tail and in the HFD. We find that adaptively evolving sites in the HFD can potentially interact with DNA, including sites in the loop 1 region of the HFD that are required for centromeric targeting in Drosophila. Other adaptively evolving sites in the HFD can be localized on the structure of the nucleosome core particle, revealing an extended surface in addition to loop 1 in which conformational changes might alter histone-DNA contacts or water bridges. The identification of adaptively evolving sites provides a structural basis for the interaction between centromeric DNA and the protein that is thought to underlie the evolution of centromeres and the accumulation of pericentric heterochromatin.

Amino Acid Sequence↗
PubMed1998

Histone Sequence Database: new histone fold family members.

Searches of the major public protein databases with core and linker chicken and human histone sequences have resulted in the compilation of an annotated set of histone protein sequences. In addition, new database searches with two distinct motif search algorithms have identified several members of the histone fold family, including human DRAP1 and yeast CSE4. Database resources include information on conflicts between similar sequence entries in different source databases, multiple sequence alignments, links to the Entrez integrated information retrieval system, structures for histone and histone fold proteins, and the ability to visualize structural data through Cn3D. The database currently contains >1000 protein sequences, which are searchable by protein type, accession number, organism name, or any other free text appearing in the definition line of the entry. All sequences and alignments in this database are available through the World Wide Web at http://www.nhgri.nih. gov/DIR/GTB/HISTONES or http://www.ncbi.nlm.nih. gov/Baxevani/HISTONES

Amino Acid Sequence↗
PubMed1977

Histone Hl-DNA interaction. Influence of phosphorylation on the interaction of histone Hl with linear fragmented DNA.

By measuring the fluorescence polarization of fluorescent histone H1 derivatives complexed with DNA, binding of the histone to DNA was studied as a function of ionic strength in the solution prior to and after the H1 phosphorylation on Ser-37 residue. Fluorescent labels were covalently linked either specifically to Tyr-72 residues or unspecifically to lysine residues in the H1 polypeptide chain. The values of the corresponding rotational relaxation times showed that at low ionic strength all the segments of the H1 molecule were immobilized on binding to DNA. The gradual increasing NaC1 concentration in the solution of H1-DNA complex was accompanied at first by additional retardation of the histone mobility in the complex, and then by progressive release of histone H1 from from the complex which was completed at 0.5-0.6 M NaC1 irrespective of phosphorylation. tat the same time the phosphorylation of histone H1 led to removal of the central and, presumably, N-terminal regions of H1 from DNA.

DNA↗
PubMed1978

Histone H1--DNA interaction. On the mechanism of DNA strands crosslinking by histone H1.

Crosslinking of DNA fibers by histone H1 or phosphorylated on Ser-37 histone H1, and by the individual fragments of the H1 polypeptide chain was studied by the method of turbidimetry. The dependence of the turbidity of DNA-protein complexes on the ionic strength in solution suggests that the condensation of H1.DNA complexes in vitro is apparently due to both specific histone-DNA interactions with the contribution of hydrogen and/or hydrophobic bonds and the formation of polycationic "bridges" fastening the DNA fibers. The effectiveness of the condensation is postulated to be a function of a proportion between the two mechanisms which in turn can be controlled by slight changes in ionic surroundings. The sharp dependence of shrinkage of H1.DNA complexes on ionic strength at "physiological" salt concentrations could provide a mechanism to regulate density and consequently the total activity of chromatin in the cell nuclei. The phosphorylation of histone H1 on Ser-37 by a specific histone kinase does not noticeably affect the pattern of DNA crosslinking by the H1.

Cations, Divalent↗
PubMed1982

Large-scale isolation and fractionation of Tetrahymena histones. Purification of H2B and H4 histones.

The histones of the ciliated protozoan Tetrahymena were isolated and fractionated on a large scale by revised procedures, and the H2B and H4 histones were highly purified for sequence determination. The nuclei of an amicronucleate strain, GL, of Tetrahymena pyriformis were isolated, without cell harvesting, from cultures reaching the stationary state, which were continuously centrifuged through 1.0 M sucrose, pH 7.5, containing Nonidet P-40. From the nuclei further purified and washed with 0.15 M NaCl, pH 7.5, histones were extracted with 0.25 M HCl. Thus 1,620 liters of cultures yielded 5.20 g of histone extract. The histones were first separated into a 0.5 M HClO4 soluble fraction (H1) and an insoluble fraction (H2A, H2B, H3, and H4). The insoluble fraction was chromatographed on a large column of Bio-Gel P-60 with 20 mM HCl containing 250 mM NaCL at 15 degrees C, yielding H2A + H3, H2B, and H4 fractions. The H4 fraction was highly pure; the H2B fraction was further purified by the same Bio-Gel P-60 chromatography without NaCl, yielding pure H2B.

Chromatography, Gel↗
PubMed1983

Studies on histone oligomers. V. Reconstitution of chromatin from purified DNA and acid-extracted histones.

DNA-histone complexes were reconstituted from DNA and acid-extracted core histones and the products were characterized by micrococcal nuclease digestion to examine whether proper nucleosome structure had been reconstituted. No nucleosome structure was produced starting from the mixture of acid-extracted histones and purified DNA in 2 M NaCl-5 M urea, while the reassociation of chromatin by the same procedures was successful. This was due to the inappropriate conformation of acid-extracted histones, which was preserved in 2 M NaCl even in the presence of 5 M urea. If acid-extracted histones were reannealed from the completely denatured state, such as in 5 M urea, 6 M guanidine hydrochloride or 0.6 M NaCl-5 M urea, reconstitution of nucleosome structure was always successful.

Animals↗
PubMed1976

Studies on the role and mode of operation of the very-lysine-rich histones in eukaryote chromatin. Nuclear-magnetic-resonance studies on nucleoprotein and histone phi 1-DNA complexes from marine invertebrate sperm.

Proton magnetic resonance and other measurements have been carried out in order to study the behaviour of the lysine-rich histones phi 1 in the sperm chromatin of certain marine invertebrates. Well defined particles (12 S) have been obtained from this chromatin by nuclease treatment. Chromatin solubility as a function of ionic strength shows a relaxation at salt concentrations higher than in the case of calf thymus nucleoprotein. Nuclear magnetic resonance (NMR) studies show that the release of histone from DNA occurs both in chromatin and in the reconstituted complexes at practically the same ionic strength as solubility relaxation. The higher the arginine content of a given phi 1, the higher the ionic strength at which both effects take place. The NMR results demonstrate that arginine residues are bound more strongly than lysine residues. The data overall show that phi 1 histones play a role in the contraction mechanism of sperm chromatin similar to that of H 1 histone in calf thymus chromatin. The highly contracted state of sperm chromatin is directly related to the increased arginine content of the phi 1 histone.

Animals↗
PubMed1976

Histone-hydrocarbon interaction. Partition of histones in aqueous two-phase systems containing poly(ethylene glycol)-bound hydrocarbons.

The hydrophobic properties of histones have been examined with help of the two-phase partition technique using dextran-poly(ethylene glycol)-water systems. We have found that different fatty acid esters of poly(ethylene glycol) interact with total histones in a manner similar to proteins of the type beta-lactoglobulin and serum albumins. Thus the maximum interaction occurs when the fatty acid contains 16-18 carbon atoms. With less than eight carbon atoms in the polymer-bound fatty acid, no histone-hydrocarbon interaction is observed. The interaction of the five individual histone fractions with palmitate depends on the type of salt used and on its concentration. We suggest that the histones can be divided into three groups with decreasing hydrophobic properties: H3, H2a greater than H4, H2b greater than H1.

Histones↗
PubMed1979

Purification and properties of a histone acetyltransferase from Artemia salina, highly efficient with H1 histone.

An histone acetyltransferase has been purified from nuclei of 40-h-old Artemia salina larvae. The enzyme is very unstable at 0 degrees C, requires free -SH groups for activity and is rapidly inactivated at 40 degrees C. The optimal pH for activity is 8.5 and the activity is half inhibited by millimolar concentrations of Mn2+, Ca2+ or Mg2+ or decimolar concentrations of Na+ and K+. The molecular weight of the enzyme, determined by gel filtration chromatography, changed with the ionic strength of the medium (280,000 in 10 mM Tris . HCl, 170,000 in 0.2 M KCl). The very-lysine-rich histone H1 is a better substrate acceptor than the arginine-rich histones H3 or H4. Under proper conditions, the enzyme can modify all the internal lysyl residues in histones H1 and H4. The acetylation of H1 is inhibited when all the other histone fractions are present in the assay mixture.

Acetyltransferases↗
PubMed1980

Proteolytic digestion studies of chromatin core-histone structure. Identification of a limit peptide of histone H2A.

Tryptic digestion of chicken erythrocyte nuclei, to a level at which no intact histone remained, resulted in a set of resistant peptides. These were partially separated by exclusion chromatography. One of the peptides was shown to represent the central sequence 12--118 of histone H2A. This was established by amino acid analysis and by Edman degradations. Comparison of the sequence of histone H2A from a wide range of cell types shows that the tryptic cleavage points correspond closely to the limits of the highly conserved central sequence and not to the limits of the strongly basic regions. It is proposed that the 11 N-terminal and 10 C-terminal residues cleaved by trypsin are exposed in chromatin and play a structural and functional role different from the central 107 residues. The exposed position of the 118--119 bond accords with the known linkage point of ubiquitin to residue 119 of histone H2A in the semi-histone A24.

Animals↗