Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HISTONES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed1975

Studies on the role and mode of operation of the very-lysine-rich histone H1 (F1) in eukaryote chromatin. The conformation of histone H1.

Proton magnetic resonance, circular dichroism and other studies of whole and cleaved calf thymus histone H1 (formerly F1) reveal the presence of specific folded structures in the region approximately from residue 40--115. Ionic, hydrogen-bond and hydrophobic interactions all appear to contribute to the stability of the structure, which is predicted to contain alpha-helices in regions 42--55 and 58--75. No evidence was found for beta-structures, either inter or intramolecular, or for any structure formation outside the region 40--115. At 18 degrees C and a protein concentration of 2 mM the first-order exchange rate between random-coil and structured forms is slower than 80 s-1; at 40 degrees C the exchange rate is faster than 330 s-1.

Animals↗
PubMed1988

The amino acid sequence of wheat histone H2B(2). A core histone with a novel repetitive N-terminal extension.

Two of the four electrophoretic histone H2B variants present in wheat embryos have been isolated. The complete primary structure of the H2B(2) variant has been deduced from sets of overlapping peptides generated by CNBr cleavage, Staphylococcus aureus V8 protease, endoproteinase Arg-C, the post-proline cleaving enzyme, chymotrypsin and cleavage in dilute acid. A minimum of 17 peptides were required to establish the sequence. This variant has a blocked N terminus and comprises a total of 149 amino acids. The C-terminal two-thirds of the protein are highly homologous to vertebrate H2B. In contrast, the N-terminal third is entirely different and contains an N-terminal extension of 23 residues in which the sequence Ala-Glu-Lys or variants are repeated several times. This region is also highly homologous to the H2B from Tetrahymena pyriformis. It shows in addition similarities to wheat H2A(1) and bovine H1.

Amino Acid Sequence↗
PubMed1969

Histone structure: asymmetric distribution of lysine residues in lysine-rich histone.

Structural studies on a very lysine-rich histone show that the carboxyl-terminal half of the molecule is enriched in lysine (and proline). which suggests that it is a site for binding to DNA. The amino-terminal half. containing most of the acidic residues. resembles small, nonhistone proteins and so might have specificity for factors other than DNA.

Amino Acid Sequence↗
PubMed2007

Linker histone HIS-24 (H1.1) cytoplasmic retention promotes germ line development and influences histone H3 methylation in Caenorhabditis elegans.

RNA interference with one of the eight Caenorhabditis elegans linker histone genes triggers desilencing of a repetitive transgene and developmental defects in the hermaphrodite germ line. These characteristics are similar to the phenotype of the C. elegans Polycomb group genes mes-2, mes-3, mes-4, and mes-6 (M. A. Jedrusik and E. Schulze, Development 128:1069-1080, 2001; I. Korf, Y. Fan, and S. Strome, Development 125:2469-2478, 1998). These Polycomb group proteins contribute to germ line-specific chromatin modifications. Using a his-24 deletion mutant and an isoform-specific antibody, we characterized the role of his-24 in C. elegans germ line development. We describe an unexpected cytoplasmic retention of HIS-24 in peculiar granular structures. This phenomenon is confined to the developing germ lines of both sexes. It is strictly dependent on the activities of the chromatin-modifying genes mes-2, mes-3, mes-4, and mes-6, as well as on the C. elegans sirtuin gene sir-2.1. A temperature shift experiment with a mes-3(ts) mutant revealed that mes gene activity is required in a time window ranging from L3 to the early L4 stage before the onset of meiosis. We find that the his-24(ok1024) mutant germ line is characterized by an increased level of the activating H3K4 methylation mark concomitant with a decrease of the repressive H3K9 methylation. In the germ line of his-24(ok1024) mes-3(bn35) double mutant animals, the repressive H3K27 methylation is more reduced than in the respective mes single mutant. These observations distinguish his-24 as an unusual element in the developmental regulation of germ line chromatin structure in C. elegans.

Active Transport, Cell Nucleus↗
PubMedDate not supplied

[Effect of insulin of acetylation of histones and non-histone proteins in the cell nuclei of the liver of albine rats of different age].

After administration of insulin acetylation of histones and acid proteins in liver cell nuclei was decreased within 30 min; it increased gradually within 120 min and there was no difference as compared with control within 360 min in young animals. Incorporation of acetate label into proteins was inhibited within 90 min after the hormone loading in old animals and it did not differ from control within 120 min. Under these conditions acetylation of globulin proteins was decreased within 30 min; it approached the control level within 60 min after which it did not distinctly alter ad compared with the control.

Acetylation↗
PubMed1992

Expression of a histone H1 gene (H1.1) in human testis and Hassall's corpuscles of the thymus. Expression of a histone H1 gene (H1.1).

The expression of a H1 gene (H1.1) was studied in several human tissues. Northern blot analysis revealed that this gene is expressed in testis and thymus, but not in other human tissues like liver, spleen, lung, brain, thyroid gland and skin fibroblasts. Furthermore in situ hybridization on tissue sections revealed a cell type specific expression of histone H1.1 gene in the Hassall's corpuscles of the thymus.

Gene Expression↗
PubMed1979

[Biochemical studies on histones of the central nervous system. III. Incorporation of [14C]-acetate into the histones of different rat brain regions during a learning experiment].

Long term memory formation obviously is accompanied by changes in macromolecule synthesis within the brain structures involved. The regulation of this process was investigated in various rat brain regions using the model of histone acetylation with [14C]-acetate during the training session, as well as 5 min and 120 min upon completion of training. Almost at all three times and in most brain structures the acetylation rate was diminished in trained animals as compared to pseudo-conditioned rats. With the exception of hippocampus labeling in trained animals was even lower in comparison to passive controls.

Acetates↗
PubMed1980

[Interaction of histones with DNA in chromatin. A new method of covalent binding of histones to DNA available for their localization on DNA].

A new method for covalent binding of histones to partially apurinized DNA was developed. Partial apurinization of DNA methylated within the composition of chromatin results in a formation of aldehyde groups interacting with the epsilon-amino groups of chromatin proteins lysine residues. The resulting Schiff's bases covalently and reversibly bind the protein molecules to DNA. This covalent binding is accompanied by a specific one-chain cleavage of DNA at the cross-linkage point in such a way that only the newly formed 5'-terminal fragment of DNA in bound to the protein. These cross-links can be stabilized via reduction of Schiff's bases by sodium borohydrate. Determination of the size of the bound DNA fragment allows to establish the localization of the cross-linkage point and the position of the protein molecule on DNA. The method of cross-linkage with a "zero length" allows to fix the immediate DNA--protein interactions and can be extensively used to study the protein--DNA interactions in cases when the epsilon-amino groups of protein lysine residues interact with DNA.

Animals↗
PubMed1980

Extensive purification of histone acetylase A, the major histone N-acetyl transferase activity detected in mammalian cell nuclei.

A concentrated, DNA-free extract of histone acetylase A was prepared from calf thymus tissues in two simple steps, which exploit the ability of polyethylene glycol to precipitate both nucleic acids and proteins from solutions containing high concentrations of salt (Alberts, B., and Herrick, G. (1971) Methods Enzymol. 21, 198-217). This extract was then chromatographed on four successive columns. The use of 75 microgram/ml of insulin as a carrier protein in all of these later steps, plus the inclusion of 1 M urea in some column buffers, has been useful in improving both the yield and reproducibility of the purification. The highly active enzyme obtained has a molecular weight of about 70,000, and the best fractions could be about 30% pure. Our data indicate that the acetylase A is only a very minor protein in cells, being present in perhaps a few thousand molecules per cell.

Acetyltransferases↗
PubMedDate not supplied

[Structure of histone fragments and their models. I. Structural features of N-terminal oligopeptides of histone H4].

Circular dichroism (CD) and infrared spectroscopy (IRS) studies of aqueous solutions of fourth N-terminal peptides of histone H4 with different chain length were carried out under various conditions. It was shown that all studied peptides had conformation of extended left-handed helix as well as poly-1-proline II at the acidic and neutral pH, in moderate ionic strength (0,15), in 80% ethanol, 0,2 M sodium dodecylsulphate, in 8 M urea and 5 M guanidinum hydrochloride. This conformation was changed by raising temperature, under transition to the range of basic pH and in the concentrated solutions of CaCl2 (5M).

Amino Acid Sequence↗