Metabolism of histones in avian erythroid cells

Sung, Michael T.; Harford, Joe B.; Bundman, Marsha C.; Vidalakas, George

doi:10.1021/bi00621a019

Cited by 57 publications

(38 citation statements)

References 27 publications

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“…Recently, Sarg et al (29) found that H5 in mature chicken erythrocytes undergoes acetylation at the N terminus and that both unacetylated and acetylated forms are present. No other H1 subtypes in these cells are known to contain any modifications although some core histones were found to be acetylated (45). To our knowledge, the presence of eventual histone modifications in mature frog erythrocytes has not been investigated, but it seems unlikely that post-translational modifications are the reason for the large differences in linker histone affinity for chromatin found between chicken and frog erythrocytes.…”

Section: Discussionmentioning

confidence: 90%

Linker Histone Subtype Composition and Affinity for Chromatin in Situ in Nucleated Mature Erythrocytes

Koutzamani

Loborg

Sarg

et al. 2002

Journal of Biological Chemistry

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The replacement linker histones H1 0 and H5 are present in frog and chicken erythrocytes, respectively, and their accumulation coincides with cessation of proliferation and compaction of chromatin. These cells have been analyzed for the affinity of linker histones for chromatin with cytochemical and biochemical methods. Our results show a stronger association between linker histones and chromatin in chicken erythrocyte nuclei than in frog erythrocyte nuclei. Analyses of linker histones from chicken erythrocytes using capillary electrophoresis showed H5 to be the subtype strongest associated with chromatin. The corresponding analyses of frog erythrocyte linker histones using reverse-phase high performance liquid chromatography showed that H1 0 dissociated from chromatin at somewhat higher ionic strength than the three additional subtypes present in frog blood but at lower ionic strength than chicken H5. Which of the two H1 0 variants in frog is expressed in erythrocytes has thus far been unknown. Amino acid sequencing showed that H1 0 -2 is the only H1 0 subtype present in frog erythrocytes and that it is 100% acetylated at its N termini. In conclusion, our results show differences between frog and chicken linker histone affinity for chromatin probably caused by the specific subtype composition present in each cell type. Our data also indicate a lack of correlation between linker histone affinity and chromatin condensation.

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Section: Discussionmentioning

confidence: 90%

Linker Histone Subtype Composition and Affinity for Chromatin in Situ in Nucleated Mature Erythrocytes

Koutzamani

Loborg

Sarg

et al. 2002

Journal of Biological Chemistry

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“…Each of the lysine residues can accept up to three methyl groups forming mono-, di-, and trimethylated derivatives, thus adding a further potential complexity to the posttranslational status of histone H3 (12,13). The detailed biological role of mono-, di-, and trimethylation, however, is completely unknown to date.…”

mentioning

confidence: 99%

Postsynthetic Trimethylation of Histone H4 at Lysine 20 in Mammalian Tissues Is Associated with Aging

Sarg

Koutzamani

Helliger

et al. 2002

Journal of Biological Chemistry

234

175

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Methylation of the N-terminal region of histones was first described more than 35 years ago, but its biological significance has remained unclear. Proposed functions range from transcriptional regulation to the higher order packing of chromatin in progress of mitotic condensation. Primarily because of the recent discovery of the SET domain-depending H3-specific histone methyltransferases SUV39H1 and Suv39h1, which selectively methylate lysine 9 of the H3 N terminus, this posttranslational modification has regained scientific interest. In the past, investigations concerning the biological significance of histone methylation were largely limited because of a lack of simple and sensitive analytical procedures for detecting this modification. The present work investigated the methylation pattern of histone H4 both in different mammalian organs of various ages and in cell lines by applying mass spectrometric analysis and a newly developed hydrophilic-interaction liquid chromatographic method enabling the simultaneous separation of methylated and acetylated forms, which obviates the need to work with radioactive materials. In rat kidney and liver the dimethylated lysine 20 was found to be the main methylation product, whereas the monomethyl derivative was present in much smaller amounts. In addition, for the first time a trimethylated form of lysine 20 of H4 was found in mammalian tissue. A significant increase in this trimethylated histone H4 was detected in organs of animals older than 30 days, whereas the amounts of mono-and dimethylated forms did not essentially change in organs from young (10 days old) or old animals (30 and 450 days old). Trimethylated H4 was also detected in transformed cells; although it was present in only trace amounts in logarithmically growing cells, we found an increase in trimethylated lysine 20 in cells in the stationary phase.In vivo methylation of the side chains of specific lysines, histidines, and arginines in proteins is a very common phenomenon in nature involving numerous classes of proteins in both prokaryotic and eukaryotic cells (1, 2). During the last several years, studies on the methylation of proteins have yielded many important observations. While these studies were under way, it was generally realized that protein methylation is far more complex and has more ramifications than originally assumed.Methylation is also a well known posttranslational modification reaction of histone proteins on lysine and/or arginine residues with a site selectivity for lysine methylation at specific positions in the N termini of histones H3 and H4. In combination with other posttranslational modifications, i.e. acetylation and phosphorylation, methylation seems to play a significant role in regulating nuclear functions. Thus, it has been suggested that distinct combinations of covalent histone modifications, also referred to as "histone code," provide a specific mark on the hydrophilic histone tails, which, when read by other proteins, cause specific downstream events finally inducing transi...

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“…The histone H5 may be considered as an H1 variant emerging in the earliest forms of erythroid cells in connection with cell specialization in embryonic [3] and adult life [4]. As erythropoiesis proceeds, the early dividing cells differentiate into non-dividing reticulocytes and then into no longer transcribing mature erythrocytes.All the histones in normal dividing cells are synthesized at the time when DNA replication occurs, while histone H5 is the only one synthesized in the non-dividing reticulocytes [5,6]. During the terminal stages of erythrocyte differentiation the histone H5 accumulated up to a ratio of 3: l for H5/Hl in mature erythrocytes, accompanied by a transition to supercompaction of the chromatin and reduced transcriptional activity.…”

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confidence: 99%

“…All the histones in normal dividing cells are synthesized at the time when DNA replication occurs, while histone H5 is the only one synthesized in the non-dividing reticulocytes [5,6]. During the terminal stages of erythrocyte differentiation the histone H5 accumulated up to a ratio of 3: l for H5/Hl in mature erythrocytes, accompanied by a transition to supercompaction of the chromatin and reduced transcriptional activity.…”

mentioning

confidence: 99%

Localization of Histone H5 in the Subunit Organization of Chromatin Using Immunoelectron Microscopy

Mazen

Murcia

Bernard³

et al. 1982

Eur J Biochem

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In avian erythroid cells the erythrocyte-specific histone H5 is involved, like H1, in the packing of nucleosomes in the 25-nm chromatin fibers. In this study the distribution of histone H5 along the polynucleosomal chains was visualized by immunoelectron microscopy.Trinucleosomes from chicken erythrocytes and liver were used in order to test the specificity of the reaction with purified rabbit anti-H5 antibodies at various ionic strengths (5 -80 mM). Long-chain chromatin was then reacted with anti-H5 antibodies and with sorted monomeric ferritin conjugate under chosen conditions.The antigenic determinants of histone H5 in the 25-nm fiber of long-chain chromatin (at 80 mM NaCl) are as accessible to the specific antibodies as in trinucleosomes.When the immunocomplexes were examined by electron microscopy in a low-ionic-strength buffer, permitting maximum extension of the chromatin structure on the grid, clusters of compacted nucleosomes were seen, separated by short regions of relaxed nucleosomes. Single nucleosomes enlarged by the antibodies are sometimes visible in the extended domains. We conclude that histone H5 is located primarily on series of adjacent nucleosomes but it can also be found on single nucleosomes located in the H1-enriched extended domains.Chicken erythrocytes contain a unique histone H5 [1,2], which also exists in the nucleated erythrocytes of a variety of non-mammalian vertebrates and even invertebrates in place of histone HI. The histone H5 may be considered as an H1 variant emerging in the earliest forms of erythroid cells in connection with cell specialization in embryonic [3] and adult life [4]. As erythropoiesis proceeds, the early dividing cells differentiate into non-dividing reticulocytes and then into no longer transcribing mature erythrocytes.All the histones in normal dividing cells are synthesized at the time when DNA replication occurs, while histone H5 is the only one synthesized in the non-dividing reticulocytes [5,6]. During the terminal stages of erythrocyte differentiation the histone H5 accumulated up to a ratio of 3: l for H5/Hl in mature erythrocytes, accompanied by a transition to supercompaction of the chromatin and reduced transcriptional activity. An unanswered question is how do the H5 molecules, synthesized last, replace the HI molecules and how are these histones distributed along the polynucleosomal chains of mature erythrocyte chromatin. We approached this question by immunoelectron microscopy, whereas Pospelov et al. [7] have recently investigated the lateral proximity of the two histone types by cross-linking experiments. Our results led to similar conclusions. MATERIALS AND METHODS Preparative ProceduresHistone H5 was extracted from purified nuclei of chicken erythrocytes as described previously [8,9]. The purity of the protein was assessed by polyacrylamide gel electrophoresis according to Weintraub [lo]. Antibodies against H5 were elicited by injection of rabbits with histone-H5 -RNA complexes as recommended by Stollar and Ward [ll]. Pure antibodies against...

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Metabolism of histones in avian erythroid cells

Cited by 57 publications

References 27 publications

Linker Histone Subtype Composition and Affinity for Chromatin in Situ in Nucleated Mature Erythrocytes

Linker Histone Subtype Composition and Affinity for Chromatin in Situ in Nucleated Mature Erythrocytes

Postsynthetic Trimethylation of Histone H4 at Lysine 20 in Mammalian Tissues Is Associated with Aging

Localization of Histone H5 in the Subunit Organization of Chromatin Using Immunoelectron Microscopy

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