Essential Role of p400/mDomino Chromatin-remodeling ATPase in Bone Marrow Hematopoiesis and Cell-cycle Progression

Abstract

p400/mDomino is an ATP-dependent chromatin-remodeling protein that catalyzes the deposition of histone variant H2A.Z into nucleosomes to regulate gene expression. We previously showed that p400/mDomino is essential for embryonic development and primitive hematopoiesis. Here we generated a conditional knock-out mouse for the p400/mDomino gene and investigated the role of p400/mDomino in adult bone marrow hematopoiesis and in the cell-cycle progression of embryonic fibroblasts. The Mx1-Cre-mediated deletion of p400/mDomino resulted in an acute loss of nucleated cells in the bone marrow, including committed myeloid and erythroid cells as well as hematopoietic progenitor and stem cells. A hematopoietic colony assay revealed a drastic reduction in colony-forming activity after the deletion of p400/mDomino. Moreover, the loss of p400/mDomino in mouse embryonic fibroblasts (MEFs) resulted in strong growth inhibition. Cell-cycle analysis revealed that the mDomino-deficient MEFs exhibited a pleiotropic cellcycle defect at the S and G 2 /M phases, and polyploid and multinucleated cells with micronuclei emerged. DNA microarray analysis revealed that the p400/mDomino deletion from MEFs caused the impaired expression of many cell-cycle-regulatory genes, including G 2 /M-specific genes targeted by the transcription factors FoxM1 and c-Myc. These results indicate that p400/ mDomino plays a key role in cellular proliferation by controlling the expression of cell-cycle-regulatory genes.The alteration of chromatin structure and function is a critical process in the transcriptional activation or repression of various cell-type-specific or developmentally regulated genes and is mainly executed by covalent histone modification and ATP-hydrolysis-dependent chromatin remodeling. All of the ATP-dependent chromatin remodelers are multisubunit protein complexes containing a SWI2/SNF2 family ATPase subunit, which plays a central role in chromatin-remodeling activities (1, 2). p400/mammalian Domino (p400/mDomino, 3 Gene symbol: Ep400), which was identified as an interaction partner for adenovirus E1A (3) and a myeloid-specific transcription factor, MZF-2A (4), is an SWR1-class chromatin-remodeling ATPase that is homologous to the yeast Swr1p and Drosophila Domino proteins (5, 6). The p400/ mDomino-containing protein complex consists of more than 10 subunits, including the Tip60 histone acetyltransferase and a PI3K family protein kinase TRRAP (3,7,8). The SWR1-class remodelers are responsible for the regulated exchange of selective histone H2A variants, such as H2A.Z, with the canonical H2A in nucleosomes (5, 9 -11). This histone-exchanging activity plays a key role in the epigenetic regulation of gene expression as well as in DNA repair (12-16). p400/mDomino is known to interact physically and/or functionally with growth-regulating transcription factors, such as Myc, p53, E2F, and adenovirus E1A (3,(17)(18)(19)(20). In primary human fibroblasts and osteosarcoma-derived U2OS cells, the knockdown of p400/mDomino results in cell-cycle arrest ...

The role of variant histone H2AV in Drosophila melanogaster larval hematopoiesis

“…dom loss-of-function mutants display black melanotic masses that are composed of melanized lymph glands (Braun et al, 1997). Mutants have shown that the vertebrate homolog of dom is required for both embryonic and adult hematopoiesis in the laboratory mouse (Fujii et al, 2010;Ueda et al, 2007). Loss of a subunit of another ATP-dependent chromatin-remodeling complex, NURF, also causes melanotic masses (Badenhorst, 2014).…”

“…These results suggested a role for Dom in prohemocyte survival. This function appears to have been conserved in mice, where a Dom homolog was shown to be important both in primitive hematopoiesis in the embryo and in the maintenance of hematopoietic progenitor cells in the adult bone marrow (Fujii et al, 2010;Ueda et al, 2007).…”

ATP-dependent chromatin remodeling during mammalian development

“…The SWR complex subunit P400 (EP400) has crucial functions during embryonic hematopoiesis (Fujii et al, 2010;Ueda et al, 2007). It regulates the expression of several embryonic globin genes and deregulates HOX gene expression.…”

“…It regulates the expression of several embryonic globin genes and deregulates HOX gene expression. In addition, the conditional deletion of P400 in bone marrow cells results in loss of the hematopoietic stem and progenitor cell pool due to defects in cell cycle progression (Fujii et al, 2010). Finally, INO80 is required for meiotic recombination during spermatogenesis (Serber et al, 2015).…”

MYC Cofactors: Molecular Switches Controlling Diverse Biological Outcomes

“…The incorporation of H2A.Z in the body of genes is associated with active transcription and reduced DNA methylation (Conerly et al 2010). Inducible knockout of p400 results in impaired gene expression, including many MYC target genes (Fujii et al 2010). In addition, knockdown of another ATPase that interacts with MYC, ASH2/ANCCA, causes a reduction in MYC target gene activation (Ciro et al 2009).…”