Epigenetic Determinants of Erythropoiesis: Role of the Histone Methyltransferase SetD8 in Promoting Erythroid Cell Maturation and Survival

• Published in: Molecular and cellular biology Vol. 35; no. 12; pp. 2073 - 2087
• Main Authors: DeVilbiss, Andrew W., Sanalkumar, Rajendran, Hall, Bryan D. R., Katsumura, Koichi R., de Andrade, Isabela Fraga, Bresnick, Emery H.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01-06-2015; American Society for Microbiology
• Subjects: Animals; Cell Survival; Cells, Cultured; Epigenesis, Genetic; Erythroid Cells - cytology; Erythroid Cells - metabolism; Erythropoiesis; GATA2 Transcription Factor - genetics; GATA2 Transcription Factor - metabolism; Gene Expression Regulation, Developmental; Histone-Lysine N-Methyltransferase - genetics; Histone-Lysine N-Methyltransferase - metabolism; Histones - metabolism; Mice; Transcriptional Activation
• ISSN: 1098-5549; 0270-7306; 1098-5549
• DOI: 10.1128/MCB.01422-14

Erythropoiesis, in which committed progenitor cells generate millions of erythrocytes daily, involves dramatic changes in the chromatin structure and transcriptome of erythroblasts, prior to their enucleation. While the involvement of the master-regulatory transcription factors GATA binding protein 1 (GATA-1) and GATA-2 in this process is established, the mechanistic contributions of many chromatin-modifying/remodeling enzymes in red cell biology remain enigmatic. We demonstrated that SetD8, a histone methyltransferase that catalyzes monomethylation of histone H4 at lysine 20 (H4K20me1), is a context-dependent GATA-1 corepressor in erythroid cells. To determine whether SetD8 controls erythroid maturation and/or function, we used a small hairpin RNA (shRNA)-based loss-of-function strategy in a primary murine erythroblast culture system. In this system, SetD8 promoted erythroblast maturation and survival, and this did not involve upregulation of the established regulator of erythroblast survival Bcl-x
L
. SetD8 catalyzed H4K20me1 at a critical Gata2 cis element and restricted occupancy by an enhancer of Gata2 transcription, Scl/TAL1, thereby repressing Gata2 transcription. Elevating GATA-2 levels in erythroid precursors yielded a maturation block comparable to that induced by SetD8 downregulation. As lowering GATA-2 expression in the context of SetD8 knockdown did not rescue erythroid maturation, we propose that SetD8 regulation of erythroid maturation involves multiple target genes. These results establish SetD8 as a determinant of erythroid cell maturation and provide a framework for understanding how a broadly expressed histone-modifying enzyme mediates cell-type-specific GATA factor function.