Histone Acetylation Is Required to Maintain the Unfolded Nucleosome Structure Associated with Transcribing DNA (original) (raw)
Related papers
A direct link between core histone acetylation and transcriptionally active chromatin
The EMBO Journal, 1988
An antiserum raised against chemically acetylated histone H4 was found to recognize the epitope e-N-acetyl lysine. Affinity-purified antibodies were used to fractionate oligoand mononucleosomal chromatin fragments from the nuclei of 15-day chicken embryo erythrocytes. Antibodybound chromatin was found to contain elevated levels of acetylated core histones. On probing with sequences of a D globin, an actively transcribed gene, the antibodybound chromatin was 15to 30-fold enriched relative to the input chromatin. Using ovalbumin sequences as a probe, no enrichment was observed. The results demonstrate directly that transcriptionally active genes carry acetylated core histones.
Biochemical and Biophysical Research Communications, 1992
The relationship between histone methylation and dynamic histone acetylation was investigated. Previously, we demonstrated in chicken erythrocytes that dynamically acetylated histones H3 and H4 of transcriptionally active gene chromatin were selectively methylated. However, methylation of these histones was not dependent upon their acetylated states. Here, we tested the hypothesis that methylation tags these histones for participation in dynamic acetylation. Using an inhibitor of protein methylation, adenosine dialdehyde, we show that the processes of histone methylation and dynamic acetylation are not directly coupled. Our results suggest that the selective methylation of dynamically acetylated chromatin reflects features of the organization of transcriptionally active gene chromatin.
The EMBO Journal
An antiserum raised against chemically acetylated histone H4 was found to recognize the epitope epsilon-N-acetyl lysine. Affinity-purified antibodies were used to fractionate oligo- and mononucleosomal chromatin fragments from the nuclei of 15-day chicken embryo erythrocytes. Antibody-bound chromatin was found to contain elevated levels of acetylated core histones. On probing with sequences of alpha D globin, an actively transcribed gene, the antibody-bound chromatin was 15- to 30-fold enriched relative to the input chromatin. Using ovalbumin sequences as a probe, no enrichment was observed. The results demonstrate directly that transcriptionally active genes carry acetylated core histones.
The Biochemical journal, 1990
The incorporation of newly synthesized histones among various chromatin fraction isolated from non-replicating cell-cycle-phase-Go chicken immature erythrocytes was investigated. We find that newly synthesized erythroid-specific histone Hl variant H5, is incorporated randomly into chromatin. In contrast, newly synthesized nucleosomal histones H2A, H2A.Z, H2B, H3.3, and H4 are preferentially found in a fraction that is highly enriched in active/competent gene chromatin fragments and depleted in repressed gene chromatin. Moreover, ubiquitinated species of histones H2A and H2B and hyperacetylated species of H4 and H2B, which are complexed to active DNA, are labelled. These observations provide evidence that newly synthesized histones preferentially exchange with the nucleosomal histones of transcriptionally active/component chromatin domains. The results of this study suggest that nucleosomes of active chromatin may be inherently less stable than bulk nucleosomes in vivo and have impli...
Purification and Characterization of Chicken Erythrocyte Histone Deacetylase 1 †
Biochemistry, 1999
Histone acetylation is involved in nuclear processes requiring chromatin remodeling. In chicken erythrocytes, DNA replication has ceased, and active reversible histone acetylation is restricted to transcriptionally active/competent chromatin domains. In this study, we set out to identify and purify the erythroid histone deacetylase responsible for catalyzing dynamic acetylation of transcriptionally active chromatin. Histone deacetylase purified from chicken erythrocytes had a molecular mass of 66 kDa. Complementary DNA encoding the chicken histone deacetylase was cloned from erythrocytes, and analysis of the derived amino acid sequence showed the chicken histone deacetylase to be the chicken homologue of mammalian HDAC1. Purified chicken erythrocyte HDAC1 deacetylated the four core histones, with a preference for H3. We present evidence that chicken HDAC1 is a metalloenzyme, the activity of which is lost when incubated with zinc chelators. In Western blot analysis with anti-HDAC1 antibodies, we found that most erythrocyte HDAC1 is associated with the low-salt insoluble chromatin fraction and, to a lesser extent, with 150 mM NaCl-soluble oligo-and polynucleosomes. The distribution of HDAC1 in erythrocyte chromatin parallels that of dynamically acetylated class 1 histones. Further, we show that HDAC1 is associated with the erythroid nuclear matrix and that the enzyme is bound to nuclear DNA in situ. We propose that in addition to catalyzing dynamic acetylation of transcribed chromatin, the enzyme has a role in the organization of nuclear DNA.
Properties of chicken erythrocyte histone deacetylase associated with the nuclear matrix
The Biochemical journal, 1996
Histone H2B is deacetylated more rapidly than H3 and H4 in chicken immature erythrocytes. Histone deacetylase from chicken immature erythrocytes was partially purified, and the histone specificities of the multiple histone deacetylase forms were determined. Ion-exchange (Q-Sepharose) and gel-exclusion (Superdex 200) chromatography of extracts from erythrocyte nuclei showed two forms (HD1 and HD2) of histone deacetylase. HD1, with a molecular mass of about 55 kDa, preferred free H3-H4 relative to H2A-H2B, while HD2, with a molecular mass of approx. 220 kDa, had a slight preference for H3-H4. HD1 and HD2 differed in pH- and ion-strength-dependence. HD2 dissociated into HD1 when treated with 1.6 M NaCl or when applied to a Q-Sepharose column. The enzymic properties of nuclear-matrix-bound histone deacetylase showed a striking difference from that of HD1 and HD2, particularly in its strong preference for H2A-H2B. Treatment of the nuclear matrix with 1.6 M NaCl and 1% 2-mercaptoethanol s...
Histone deacetylase is a component of the internal nuclear matrix
Journal of Biological Chemistry
In chicken immature erythrocytes, approximately 4% of the modifiable histone lysine sites participate in active acetylation. There are two categories of actively acetylated histone H4. Although both are acetylated at the same rate (t1/2 = 12 min), one is acetylated to the tetraacetylated form and is rapidly deacetylated (class 1), and the other is acetylated to mono- and diacetylated forms and is slowly deacetylated (class 2). We show that the chromatin distribution of the class 1 labeled tetraacetylated H4 species paralleled that of the transcriptionally active DNA sequences. For example, the chromatin fragments of the insoluble nuclear material contained 76% of the active DNA and 74% of the labeled tetraacetylated H4. Class 2 labeled acetylated H4 species were found in repressed chromatin and were enriched in active/competent gene-enriched chromatin fragments. The majority of the histone deacetylase activity (75-80%) was located with the insoluble residual nuclear material. Furthe...