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Study conducted presents the first evidence that the SNF2-like ATPase Mi-2[beta] of the Nucleosome Remodeling Deacetylase (NuRD) complex is required for maintenance of and multilineage differentiation in the early hematopoietic hierarchy. It is observed that Mi-2[beta] provides the hematopoietic system with immune cell capabilities and an extensive regenerative capacity.

Cell fate depends on the interplay between chromatin regulators and transcription factors. Here we show that activity of the Mi-2? nucleosome-remodeling and histone-deacetylase (NuRD) complex was controlled by the Ikaros family of lymphoid lineage-determining proteins. Ikaros, an integral component of the NuRD complex in lymphocytes, tethered this complex to active genes encoding molecules involved in lymphoid differentiation. Loss of Ikaros DNA-binding activity caused a local increase in chromatin remodeling and histone deacetylation and suppression of lymphoid cell-specific gene expression. Without Ikaros, the NuRD complex also redistributed to transcriptionally poised genes that were not targets of Ikaros (encoding molecules involved in proliferation and metabolism), which induced their reactivation. Thus, release of NuRD from Ikaros regulation blocks lymphocyte maturation and mediates progression to a leukemic state by engaging functionally opposing epigenetic and genetic networks. [ABSTRACT FROM AUTHOR]

Cell fate decisions depend on the interplay between chromatin regulators and transcription factors. Here we show that activity of the Mi-2β nucleosome remodeling and deacetylase (NuRD) complex was controlled by the Ikaros family of lymphoid-lineage determining proteins. Ikaros, an integral component of the NuRD complex in lymphocytes, tethered this complex to active lymphoid differentiation genes. Loss in Ikaros DNA binding activity caused a local increase in Mi-2β chromatin remodeling and histone deacetylation and suppression of lymphoid gene expression. The NuRD complex also redistributed to transcriptionally poised non-Ikaros gene targets, involved in proliferation and metabolism, inducing their reactivation. Thus, release of NuRD from Ikaros regulation blocks lymphocyte maturation and mediates progression to a leukemic state by engaging functionally opposing epigenetic and genetic networks.