ADP-ribosylation of pancreatic histone H1 and of other histones

1980 ◽  
Vol 58 (6) ◽  
pp. 509-515 ◽  
Author(s):  
G. G. Poirier ◽  
P. Savard

Incubation of pancreatic nuclei with high NAD concentrations resulted in increased ADP-ribosylation of histone H1. Interaction of [3H]ADP-ribosylated histone H1 with chromatin was significantly different from unmodified histone H1. The presence of a protein which is eluted at a lower salt concentration and which is ADP-ribosylated was also noticed. Pancreatic histones were isolated by column chromatography and their degree of ADP-ribosylation evaluated both by gel electrophoresis and by chromatography: histone H1 was the main acceptor while the core histones H3, H2B, and H2A were lightly labelled. Histones H1 and H10 have a differential binding to pancreatic chromatin and histone H10 is not ADP-ribosylated.

2001 ◽  
Vol 79 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Missag H Parseghian ◽  
Barbara A Hamkalo

The last 35 years has seen a substantial amount of information collected about the somatic H1 subtypes, yet much of this work has been overshadowed by research into highly divergent isoforms of H1, such as H5. Reports from several laboratories in the past few years have begun to call into question some of the traditional views regarding the general function of linker histones and their heterogeneity. Hence, the impression in some circles is that less is known about these ubiquitous nuclear proteins as compared with the core histones. The goal of the following review is to acquaint the reader with the ubiquitous somatic H1s by categorizing them and their characteristics into several classes. The reasons for our current state of misunderstanding is put into a historical context along with recent controversies centering on the role of H1 in the nucleus. Finally, we propose a model that may explain the functional role of H1 heterogeneity in chromatin compaction.Key words: histone H1, linker histones, chromatin organization, chromatin compaction, heat shock.


1981 ◽  
Vol 50 (1) ◽  
pp. 199-208
Author(s):  
J.M. Levin ◽  
P.R. Cook

When HeLa cells are lysed in solutions containing a non-ionic detergent and 0.75 M-NaCl, structures are released that retain many of the morphological features of nuclei. These nucleoids contain all the nuclear DNA, RNA and the ‘core’ histones, but few other proteins characteristic of chromatin. Their DNA is intact. The core histones dissociate on raising the salt concentration. We have probed the structure of nucleoid-histone complexes using the intercalating dye, ethidium, or the RNA polymerase of Escherichia coli. Both have a higher affinity for superhelical DNA than they do for relaxed DNA. The binding of ethidium is measured fluorometrically, and using this probe we find that the DNA of nucleoids containing all the core histones behaves as if it were supercoiled slightly positively. As the salt concentration is increased, free energy characteristic of negative supercoiling appears between 0.92 M and 0.95 M-NaCl. This transition, which is reversible in the presence of the arginine-rich histones, occurs without dissociation of these histones from the DNA and so must reflect a conformational change in the complex. In contrast to the results with ethidium, we find that RNA polymerase can detect the presence of some negative free energy of supercoiling in nucleoids containing the core histones. The transformations of the free energy that can assist the binding of ethidium and RNA polymerase are discussed.


1986 ◽  
Vol 64 (8) ◽  
pp. 750-757 ◽  
Author(s):  
Richard Desrosiers ◽  
Robert M. Tanguay

The effects of a heat shock or arsenite treatment on the methylation and acetylation of core histones have been investigated in Drosophila cultured cells. The decrease in H3 methylation, which is observed during a heat shock, is not a demethylation process, but results from methylation arrest. Two-dimensional gel electrophoresis leaves no ambiguity concerning the identity of H2B as a methylated protein, since H2B and D2, a nuclear nonhistone protein, which comigrate on one-dimensional gels, are well separated on these gels. Two-dimensional gel electrophoresis in the presence of Triton X-100 resolves each of the core histones into multiple forms resulting from posttranslational modifications. There are apparently, however, no histone variants in cultured Drosophila cells. At 23 °C, the various forms of the core histones resolved on two-dimensional gels are methylated. Under heat-shock or arsenite treatment, the methylation of all forms of H3 is decreased, while that of the various forms of H2B increases. These stress conditions also induce a generalized diminution in the acetylation of all forms of core histones. In the course of a heat shock, the synthesis of H2B is increased and this newly synthesized histone remains unacetylated during the shock. These changes in the patterns of core histone methylation and acetylation may be correlated with the reorganization of gene activity brought about by the heat shock.


1982 ◽  
Vol 60 (3) ◽  
pp. 295-305 ◽  
Author(s):  
R. J. Aubin ◽  
V. T. Dam ◽  
J. Miclette ◽  
Y. Brousseau ◽  
G. G. Poirier

When pancreatic chromatin fragments were prepared and resolved in the presence of 80 mM NaCl, endogenous poly(ADP-ribose) polymerase activity was found to be maximal in nucleosome periodicities of four to five units and did not respond to any further increases in nucleosomal architecture. Furthermore, in nucleosome complexities spanning 1 through 14 and over unit lengths, polyacrylamide gel electrophoresis on acid–urea and acid–urea–Triton gels has shown pancreatic histone H1 to be the only actively ADP-ribosylated histone species. The extent of ADP-ribosylation of histone H1 was also demonstrated to retard the protein's mobility in acid–urea, acid–urea–Triton, and lithium dodecyl sulfate polyacrylamide gels and to consist of at least 12 distinct ADP-ribosylated species extractable in all nucleosome complexities studied. Finally, extraction and subsequent electrophoresis of total chromosomal proteins in the presence of lithium dodecyl sulfate also evidenced heavy ADP-ribosylation at the level of nonhistone chromosomal proteins of the high mobility group comigrating in the core histone region, as well as in the topmost region of the gels where poly(ADP-ribose) polymerase was found to form a poly(ADP-ribosyl)ated aggregate.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eva Höllmüller ◽  
Simon Geigges ◽  
Marie L. Niedermeier ◽  
Kai-Michael Kammer ◽  
Simon M. Kienle ◽  
...  

AbstractDecoding the role of histone posttranslational modifications (PTMs) is key to understand the fundamental process of epigenetic regulation. This is well studied for PTMs of core histones but not for linker histone H1 in general and its ubiquitylation in particular due to a lack of proper tools. Here, we report on the chemical synthesis of site-specifically mono-ubiquitylated H1.2 and identify its ubiquitin-dependent interactome on a proteome-wide scale. We show that site-specific ubiquitylation of H1 at position K64 modulates interactions with deubiquitylating enzymes and the deacetylase SIRT1. Moreover, it affects H1-dependent chromatosome assembly and phase separation resulting in a more open chromatosome conformation generally associated with a transcriptionally active chromatin state. In summary, we propose that site-specific ubiquitylation plays a general regulatory role for linker histone H1.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1152
Author(s):  
Tatyana Kirila ◽  
Anna Smirnova ◽  
Alla Razina ◽  
Andrey Tenkovtsev ◽  
Alexander Filippov

The water–salt solutions of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines were studied by light scattering and turbidimetry. The core was hexaaza[26]orthoparacyclophane and the arms were poly-2-ethyl-2-oxazine, poly-2-isopropyl-2-oxazine, poly-2-ethyl-2-oxazoline, and poly-2-isopropyl-2-oxazoline. NaCl and N-methylpyridinium p-toluenesulfonate were used as salts. Their concentration varied from 0–0.154 M. On heating, a phase transition was observed in all studied solutions. It was found that the effect of salt on the thermosensitivity of the investigated stars depends on the structure of the salt and polymer and on the salt content in the solution. The phase separation temperature decreased with an increase in the hydrophobicity of the polymers, which is caused by both a growth of the side radical size and an elongation of the monomer unit. For NaCl solutions, the phase separation temperature monotonically decreased with growth of salt concentration. In solutions with methylpyridinium p-toluenesulfonate, the dependence of the phase separation temperature on the salt concentration was non-monotonic with minimum at salt concentration corresponding to one salt molecule per one arm of a polymer star. Poly-2-alkyl-2-oxazine and poly-2-alkyl-2-oxazoline stars with a hexaaza[26]orthoparacyclophane core are more sensitive to the presence of salt in solution than the similar stars with a calix[n]arene branching center.


Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 961-973 ◽  
Author(s):  
Shan M Hays ◽  
Johanna Swanson ◽  
Eric U Selker

Abstract We have identified and characterized the complete complement of genes encoding the core histones of Neurospora crassa. In addition to the previously identified pair of genes that encode histones H3 and H4 (hH3 and hH4-1), we identified a second histone H4 gene (hH4-2), a divergently transcribed pair of genes that encode H2A and H2B (hH2A and hH2B), a homolog of the F/Z family of H2A variants (hH2Az), a homolog of the H3 variant CSE4 from Saccharomyces cerevisiae (hH3v), and a highly diverged H4 variant (hH4v) not described in other species. The hH4-1 and hH4-2 genes, which are 96% identical in their coding regions and encode identical proteins, were inactivated independently. Strains with inactivating mutations in either gene were phenotypically wild type, in terms of growth rates and fertility, but the double mutants were inviable. As expected, we were unable to isolate null alleles of hH2A, hH2B, or hH3. The genomic arrangement of the histone and histone variant genes was determined. hH2Az and the hH3-hH4-1 gene pair are on LG IIR, with hH2Az centromere-proximal to hH3-hH4-1 and hH3 centromere-proximal to hH4-1. hH3v and hH4-2 are on LG IIIR with hH3v centromere-proximal to hH4-2. hH4v is on LG IVR and the hH2A-hH2B pair is located immediately right of the LG VII centromere, with hH2A centromere-proximal to hH2B. Except for the centromere-distal gene in the pairs, all of the histone genes are transcribed toward the centromere. Phylogenetic analysis of the N. crassa histone genes places them in the Euascomycota lineage. In contrast to the general case in eukaryotes, histone genes in euascomycetes are few in number and contain introns. This may be a reflection of the evolution of the RIP (repeat-induced point mutation) and MIP (methylation induced premeiotically) processes that detect sizable duplications and silence associated genes.


2014 ◽  
Vol 5 (8) ◽  
pp. 3061-3070 ◽  
Author(s):  
Yohei Kotsuchibashi ◽  
Ravin Narain

Dual-temperature and pH responsive (ethylene glycol)-based nanogels were synthesized. Both the core and the shell of the nanogels showed a lower critical solution temperature (LCST) and the LCST of the shell was strongly affected by the solution pH and salt concentration due to the presence of carboxylic acid groups at the nanogel surface.


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