Chromatin condensation in terminally differentiating mouse erythroblasts does not involve special architectural proteins but depends on histone deacetylation

• Published in: Chromosome research Vol. 17; no. 1; pp. 47 - 64
• Main Authors: Popova, Evgenya Y, Krauss, Sharon Wald, Short, Sarah A, Lee, Gloria, Villalobos, Jonathan, Etzell, Joan, Koury, Mark J, Ney, Paul A, Chasis, Joel Anne, Grigoryev, Sergei A
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 2009; Springer Netherlands; Springer Nature B.V
• Subjects: Acetylation; Animal Genetics and Genomics; Animals; Biomedical and Life Sciences; Blood cells; Cell Biology; Cell Differentiation; Chickens; Chromatin; Chromatin - metabolism; chromatin condensation; Chromosomes; Condensation; Data processing; Deacetylation; Differentiation; enucleation; erythroblast; Erythroblasts; Erythroblasts - metabolism; Erythropoiesis; Evolutionary biology; Friend murine leukemia virus - metabolism; Heterochromatin; histone; Histone deacetylase; Histone Deacetylase Inhibitors; Histone Deacetylases - genetics; Histone Deacetylases - metabolism; Histones - metabolism; Human Genetics; Hydroxamic Acids - pharmacology; Life Sciences; Methylation; Mice; Nucleosomes; Nucleosomes - metabolism; Plant Genetics and Genomics; Proteins; Rodents; Spleen; Trichostatin A; chromatin condensation; erythroblast; histone; deacetylation; enucleation; heterochromatin
• ISSN: 0967-3849; 1573-6849
• DOI: 10.1007/s10577-008-9005-y

Terminal erythroid differentiation in vertebrates is characterized by progressive heterochromatin formation and chromatin condensation and, in mammals, culminates in nuclear extrusion. To date, although mechanisms regulating avian erythroid chromatin condensation have been identified, little is known regarding this process during mammalian erythropoiesis. To elucidate the molecular basis for mammalian erythroblast chromatin condensation, we used Friend virus-infected murine spleen erythroblasts that undergo terminal differentiation in vitro. Chromatin isolated from early and late-stage erythroblasts had similar levels of linker and core histones, only a slight difference in nucleosome repeats, and no significant accumulation of known developmentally regulated architectural chromatin proteins. However, histone H3(K9) dimethylation markedly increased while histone H4(K12) acetylation dramatically decreased and became segregated from the histone methylation as chromatin condensed. One histone deacetylase, HDAC5, was significantly upregulated during the terminal stages of Friend virus-infected erythroblast differentiation. Treatment with histone deacetylase inhibitor, trichostatin A, blocked both chromatin condensation and nuclear extrusion. Based on our data, we propose a model for a unique mechanism in which extensive histone deacetylation at pericentromeric heterochromatin mediates heterochromatin condensation in vertebrate erythroblasts that would otherwise be mediated by developmentally-regulated architectural proteins in nucleated blood cells.