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Query: HUMANGGP:040116 (histone)
 44,835 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a membrane filter assay, we have obtained results from both kinetic and competition experiments indicating that histones bind more strongly to bromodeoxyuridine-substituted DNA than to normal DNA. At 37 degrees C in our standard buffer of 0.2 M ionic strength, the rate of dissociation of histones H1, H2, and h4 from BrdU-substituted DNA is respectively 7, 4, and 2 times slower than it is from normal DNA. Competition experiments show an even greater difference between BrdU-substituted and normal DNA with respect to histone binding. The tighter binding of histones to BrdU-substituted DNA is of interest because of the known effects of BrdU on eukaryotic chromosome condensation and staining, virus induction, and the inhibition of differentiation.
Nucleic Acids Res 1976 Sep
PMID:Histones bind more tightly to bromodeoxyuridine-substituted DNA than to normal DNA. 0 22

Adenosine 3',5'-cyclic monophosphate (cAMP) may be one of the important factors in regulating the expression of many differentiated functions in neuroblastoma cells, but some of these functions can be induced by agents that do not increase the intracellular level of cAMP. An elevation of the intracellular level of guanosine 3',5'-cyclic monophosphate (cGMP) neither induced differentiation nor antagonized the effects of cAMP. Neuroblastoma cells increased the level of cAMP-binding proteins during differentiation, whereas glial cells and L-cells did not. This might have accounted in part for an increase in the intracellular level of cAMP even in the presence of high phosphodiesterase activity in neuroblastoma cells, since the protein-bound with the same proteins, but cAMP had about 10 times higher affinity than did cGMP. cAMP promoted the organization of microtubules and microfilaments necessary for the expression of differentiated phenotypes. The extension of neurites required the synthesis of new protein, but it did not need the synthesis of new RNA. cAMP induced differentiation in neuroblastoma cells by increasing the expression of some genetic information while suppressing the expression of others; e.g., the activities of neural enzymes increased, whereas the synthesis of histone and the phosphorylation of H1-histone markedly decreased in differentiated cells. A hypothesis was offered: An increase in cAMP phosphodiesterase activity as a result of mutation in the regulatory gene for phosphodiesterase in a single, or group of, dividing nerve cell(s) is the primary lesion that leads to malignancy. Based on the concept that selective cytocytoxic drugs should be used with agents that cause differentiation, a new therapeutic approach was suggested for the treatment of neuroblastoma. This involved administration of sodium butyrate followed by L-DOPA or prostaglandin E1 in the presence of cAMP phosphodiesterase inhibitor followed by the less immunosuppressive vincristine and 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide.
J Natl Cancer Inst 1976 Sep
PMID:Cyclic nucleotides in the regulation of expression of differentiated functions in neuroblastoma cells. 1 Apr 49

The interactions of H1 (H1A, H1B), H2A, H2B, H3, H4, and H5 with phenyl cross-linked agarose were studied. Procedures are described whereby all six histones can be bound, released, and fractionated by using appropriate salt concentrations or pH. The binding can be totally abolished by inclusion of hydrophobic disrupting agents. Control experiments with nonderivated cross-linked agarose ruled out a passive aggregation-disaggregation phenomenon governing the binding patterns. The absorption sequence based on the identification and quantitation of individual histones from either unfractionated (whole) histone or separate histone classes is as follows: H3 greater than or equal to H4 greater than H2B greater than or equal to H5 greater than or equal to H2A greater than H1A greater than or equal to H1B. The order differs only slightly from the reverse of the desorption sequence, H1B less than or equal to H1A less than or equal to H5 less than H2A less than or equal to H3. Preferential interaction of H2A-H2B, H3-H4, and H2A-H2B-H4 occur; these interactions can modify the original relative affinity of each individual component for the matrix. The variability in matrix affinity appears to involve simple stoichiometry of the histone components.
Can J Biochem 1978 Sep
PMID:Fractionation of avian erythrocyte histones by hydrophobic interaction chromatography. 3 71

Isoniazid and hydralazine were covalently crosslinked by epidermal transglutaminase to serum and cell nuclear proteins. Albumin and nucleohistones were excellent acceptors of these drugs in serum and nuclear extracts, respectively. Drug-albumin and drug-histone conjugates were highly antigenic in rabbits within 4 weeks, eliciting drug-specific antibodies in all immunized animals. A radioimmunoassay for antibodies to isoniazid were developed, using a standard drug-albumin conjugate. The methods described here of enzymatic crosslinking of drugs to proteins facilitate studies of drug-induced hypersensitivity in animals and man.
J Invest Dermatol 1979 Sep
PMID:The role of enzymatic coupling of drugs to proteins in induction of drug specific antibodies. 3 85

Staining of nervous tissue sections with ammoniacal silver according to Black et al. has been confirmed to be a reliable histochemical colour reaction for quantitative evaluation of arginine-rich and lysine-rich histones in cell structures on the basis of determinations of the position of spectral curve maximum. Neurons of several brain nuclei which differed in predominating neurotransmitter did not differ in the ratio of arginine-rich to lysine-rich histones while some differences in this ratio were found out in the glial satelite cells adjacent to the corresponding neurons of these nuclei. Moderate circadian fluctuations were observed in the arginine-rich to lysine-rich histone ratio, these fluctuations being rather similar in the neurons studied and in the cells of perineuronal neuroglia.
Microsc Acta 1978 Sep
PMID:Quantitative microspectral evaluation of the ratio of arginine-rich to lysine-rich histones in neurons and neuroglial cells. 8 97

Epiphyseal growth plate chondrocyte nuclei of growing rats were studied for histone content using the ammoniacal silver technique. This stain, which is specific for the demonstration of the arginine-rich fractions of histones, revealed that growth plate nuclei vary in their histone content. Nuclei of cells of the proliferating zone revealed a significantly greater amount of postformalin ammoniacal silver deposit consistent with the presence of arginine-rich histones.
Anat Rec 1979 Sep
PMID:Ultrastructural localization of histones in epiphyseal chondrocytes. 9 33

Normal sera and plasma, derived from humans, calves, rats, rabbits, horses, human synovial fluids, inflammatory exudates, and leukocyte extracts, when sufficiently diluted are highly bacteriolytic for Staph, aureus, Strep. faecalis, B. sutilis and to a variety of gram-negative rods. On the other hand, concentrated serum or the other body fluids are usually not bacteriolytic for these bacterial species. While the lysis of Staph, aureus and B. subtilis by diluted serum is not lysozyme dependent, lysis of Strep. faecalis is absolutely dependent on the concentration of lysozyme. The lytic factor in human serum is present in Cohn's fractions III, IV, and V. It is nondialyzable, resistant to heating for 75 degrees C and 20 min, and acts optimally at pH 5.0. Like leukocyte extracts, synovial fluids, and inflammatory exudates, it lyses only young staphylococci. The inability of concentrated serum to lyse Staph. aureus and Strep. faecalis is due to the presence in the gamma globulin fraction of a potent inhibitor, which can be partly removed by dilution of by adsorption upon the homologous bacteria. Lysis of the bacteria is also strongly inhibited by Cohn's fraction II (gamma globulin) by high-molecular-weight DNA, heparin, liquoid, and histone. The possible role played by serum globulin in the protection of bacteria against degradation by leukocyte is discussed.
Inflammation 1979 Sep
PMID:Effect of leukocyte hydrolases on bacteria. XIV. Bacteriolytic effects of human sera, synovial fluids, and purulent exudates on Staphylococcus aureus and Streptococcus faecalis: modulation by Cohn's fraction II and by polyelectrolytes. 9 58

High mobility group (HMG) nonhistone chromosomal proteins have been shown to exist also in the ciliated protozoan Tetrahymena pyriformis. One or two histone-like components were extracted with 0.25 M HCl from the chromatin, in addition to five histone species. These proteins were also extracted selectively with 0.5 M HClO4, 0.35 M NaCl, or 4 mM spermidine, together with H1 histone, and were characterized as HMG proteins on the basis of the following criteria: high mobilities on polyacrylamide gel electrophoresis, relatively low molecular weights, amino acid compositions rich in lysine and glutamic acid, and relative contents in chromatin. This extends the distribution of the HMG proteins to all four eukaryotic kingdoms, and suggests the possibility that they have some universal role in chromatin structure and function.
J Biochem 1979 Sep
PMID:High mobility group nonhistone chromosomal proteins also exist in Tetrahymena. 11 5

Guanosine 3':5'-monophosphate(cyclic GMP)-dependent protein kinase which catalyzes the phosphorylation of histone was purified about 200-fold from the soluble fraction of pig lung by pH 5.5 precipitation, DEAE-cellulose column chromatography, and Sephadex G-200 gel filtration. The apparent Ka values for guanosine 3':5'-monophosphate and adenosine 3':5'-monophosphate were determined to be about 17 and 360 nM, respectively. Mg2+ was essential for the activity exhibiting biphasic stimulation behavior and neither Mn2+ nor Ca2+ could substitute for Mg2+. However, these divalent ions markedly inhibited the protein kinase activity stimulated by cyclic GMP in the presence of Mg2+.
J Biol Chem 1975 Sep 25
PMID:Partial purification and properties of guanosine 3':5'-monophosphate-dependent protein kinase from pig lung. 17 Feb 61

In liver regeneration or neoplastic transformation, phosphorylation of nuclear proteins is stimulated. In the regenerating liver all main histone fractions are involved in this process. The type of histone phosphorylated seems to be dependent on the position of the partially synchronized cells within the generation cycle. At a time when most cells are exhibiting maximum HnRNA-synthesis, histone F2a2 belongs to those fractions with highly stimulated phosphate incorporation. Phosphorylation of this fraction alone is stimulated by cyclic AMP in parallel to a stimulation of HnRNA-synthesis. The preneoplastic liver is characterized by oscillating phosphorylation and dephosphorylation reactions of nearly all histone fractions during the first days of N-nitroso-diethylamine administration. After 2 months of carcinogen feeding a 50-150% stimulation of the phosphorylation of Fl subfractions is observed. The phosphate content of the other histones, however, has returned to the original level. A series of further proteins, isolated together with the histones, show very similar phosphorylation characteristics. These proteins are mostly of non-histone origin. It is suggested that some of them are responsible for the transport of RNA with messenger properties within the cell.
Cell Tissue Kinet 1975 Sep
PMID:The phosphorylation of nuclear proteins in the regenerating and premalignant rat liver and its significance for cell proliferation. 17 Oct 70


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