scholarly journals Conformational changes in rat liver chromatin after liver regeneration

1981 ◽  
Vol 193 (3) ◽  
pp. 671-678 ◽  
Author(s):  
H Simpkins ◽  
L M Thompson ◽  
N Waldeck ◽  
D S Gross ◽  
D Mooney
Keyword(s):  
Dna Synthesis ◽  
Rat Liver ◽  
Conformational Changes ◽  
Histone H3 ◽  
Tryptophan Fluorescence ◽  
Chromatin Protein ◽  
Detectable Difference ◽  
Liver Chromatin ◽  
Triton X

N-Pyrenemaleimide, a fluorescent probe that specifically labels histone H3 of rat liver chromatin in situ, was used to monitor the accessibility of histone H3 in chromatin isolated from rat liver at different times during degeneration. At times of maximum DNA synthesis (18–24 h after hepatectomy), the accessibility of the probe was found to be markedly (40–50%) increased. This increase is abolished, however, by treatment of the chromatin fibres with high salt (2 M-NaCl) or detergent. Tryptophan fluorescence was also enhanced at points of maximum DNA synthesis, suggesting that some non-histone tryptophan-containing protein was being synthesized. The polarization of the labelled histone H3 is not markedly altered, suggesting that fibre aggregation or dissociation does not occur. Mononucleosomes extracted from sham-operated and hepatectomized animals did not exhibit any difference in binding to the probe. Also, analysis of the chromatin protein by electrophoresis on detergent- and acid/urea/ Triton-X-100-containing polyacrylamide gels showed no detectable difference in histone H3 : 1, H3 : 2 or H3 : 3 subclasses.

scholarly journals 2',3'-dideoxy-3'-aminonucleoside-5'-triphosphates inhibit repair DNA synthesis in rat liver chromatin

1985 ◽  
Vol 1 (3) ◽  
pp. 125-131 ◽  
Author(s):  
A. A. Kraevsky ◽  
M. K. Kukhanova ◽  
L. A. Alexandrova ◽  
N. V. Belyakova ◽  
V. M. Krutyakov
Keyword(s):  
Dna Synthesis ◽  
Rat Liver ◽  
Liver Chromatin

Intrinsic tryptophan fluorescence of rat liver elongation factor eEF-2 to monitor the interaction with guanylic and adenylic nucleotides and related conformational changes

Biochemistry ◽  
1993 ◽  
Vol 32 (8) ◽  
pp. 1976-1980 ◽  
Author(s):  
Bruno Sontag ◽  
Anne Marie Reboud ◽  
Gilles Divita ◽  
Attilio Di Pietro ◽  
Dominique Guillot ◽  
...  
Keyword(s):  
Rat Liver ◽  
Conformational Changes ◽  
Elongation Factor ◽  
Tryptophan Fluorescence ◽  
Intrinsic Tryptophan Fluorescence

A Disappearance of a 24-kDa Acid-Soluble Protein from Liver Chromatin of Normal and Starved Hens Following ᴅ-Galactosamine Administration

1985 ◽  
Vol 40 (11-12) ◽  
pp. 798-805 ◽  
Author(s):  
Jan Pałyga
Keyword(s):  
Gel Electrophoresis ◽  
Rna Synthesis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Two Dimensional ◽  
Chromatin Protein ◽  
Ionic Detergent ◽  
Liver Chromatin ◽  
Chromatin Proteins ◽  
Triton X

Abstract Normal and starved adult chickens were injected intraperitoneally with ᴅ-galactosamine hydro­ chloride (0.5 g/kg body weight) and 6 h later liver chromatin acid-soluble proteins were isolated. These proteins were resolved by a two-dimensional polyacrylamide gel electrophoresis in the presence of non-ionic detergent, Triton X-100, in the first dimension and anionic detergent, sodium dodecyl sulfate, in the second dimension. Although spotting patterns of acid-soluble chromatin proteins were remarkably similar between normal and starved control birds and those receiving ᴅ-galactosamine, a disappearance of a 24-kDa protein after administration of this agent was found. Moreover, it was shown that this protein was also completely absent in the chicken erythrocyte chromatin which was known to be inactive in RNA synthesis.It seems that the disappearance of the 24-kDa chromatin protein may be associated with inhibiting of transcription in hen liver after ᴅ-galactosamine administration and during hen erythrocyte maturation.

SEM of non-coated hepatocellular cytoskeleton of perfused livers

1984 ◽  
Vol 42 ◽  
pp. 306-307
Author(s):  
S.W. French ◽  
N.C. Benson ◽  
C. Davis-Scibienski
Keyword(s):  
Ambient Temperature ◽  
Critical Point ◽  
Protease Inhibitors ◽  
Metal Deposition ◽  
Heat Damage ◽  
Detergent Extraction ◽  
Cytoskeletal Elements ◽  
Triton X ◽  
Excised Tissue

Previous SEM studies of liver cytoskeletal elements have encountered technical difficulties such as variable metal coating and heat damage which occurs during metal deposition. The majority of studies involving evaluation of the cell cytoskeleton have been limited to cells which could be isolated, maintained in culture as a monolayer and thus easily extracted. Detergent extraction of excised tissue by immersion has often been unsatisfactory beyond the depth of several cells. These disadvantages have been avoided in the present study. Whole C3H mouse livers were perfused in situ with 0.5% Triton X-100 in a modified Jahn's buffer including protease inhibitors. Perfusion was continued for 1 to 2 hours at ambient temperature. The liver was then perfused with a 2% buffered gluteraldehyde solution. Liver samples including spontaneous tumors were then maintained in buffered gluteraldehyde for 2 hours. Samples were processed for SEM and TEM using the modified thicarbohydrazide procedure of Malich and Wilson, cryofractured, and critical point dried (CPD). Some samples were mechanically fractured after CPD.

scholarly journals Histone H3 Lysine 4 Methylation Marks Postreplicative Human Cytomegalovirus Chromatin

2012 ◽  
Vol 86 (18) ◽  
pp. 9817-9827 ◽  
Author(s):  
Alexandra Nitzsche ◽  
Charlotte Steinhäußer ◽  
Katrin Mücke ◽  
Christina Paulus ◽  
Michael Nevels
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Histone Modification ◽  
Dna Polymerase ◽  
Human Cytomegalovirus ◽  
Viral Genome ◽  
Histone H3 ◽  
Viral Dna ◽  
The Impact ◽  
Preferential Incorporation

In the nuclei of permissive cells, human cytomegalovirus genomes form nucleosomal structures initially resembling heterochromatin but gradually switching to a euchromatin-like state. This switch is characterized by a decrease in histone H3 K9 methylation and a marked increase in H3 tail acetylation and H3 K4 methylation across the viral genome. We used ganciclovir and a mutant virus encoding a reversibly destabilized DNA polymerase to examine the impact of DNA replication on histone modification dynamics at the viral chromatin. The changes in H3 tail acetylation and H3 K9 methylation proceeded in a DNA replication-independent fashion. In contrast, the increase in H3 K4 methylation proved to depend widely on viral DNA synthesis. Consistently, labeling of nascent DNA using “click chemistry” revealed preferential incorporation of methylated H3 K4 into viral (but not cellular) chromatin during or following DNA replication. This study demonstrates largely selective epigenetic tagging of postreplicative human cytomegalovirus chromatin.

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