The histone lysine acetyltransferase HBO1 regulates hematopoietic stem cell quiescence and self-renewal

KAT7 (HBO1) is a histone acetyltransferase required for histone H3 lysine 14 acetylation (H3K14ac) and normal levels of gene expression in hematopoietic stem and progenitor cells (HSPCs). The loss of H3K14ac was detected by western blot in whole bone marrow and by flow cytometry in specific HSPC populations. In order to determine the normal distribution of H3K14ac in the HSPC population a CUT&Tag experiment was performed using lineage negative, cKit positive Sca1 positive cells (LSK) and lineage negative, cKit positive Sca1 negative cells (progenitor cells). HBO1 was deleted using the poly(I:C) inducible MX1-cre recombinase transgene and compared to Kat7 heterozygous control cells, in which the MX1-cre was likewise induced. Analysis was performed at a stage when H3K14ac was no longer detectable by western blot. In order to control for the effects of PCR amplification and normalisation of library size before sequencing, equal numbers of Drosophila Schneider 2 cells were added to each sorted mouse cell population (“spike in”). After sequencing-read quality control, reads were mapped to a combined Mus musculus (Mm10) and Drosophila melanogaster (DmelR635) genome. To each mouse sample a normalisation factor based on the recovery of Drosophila reads within the same sample was applied. Genomic distribution of KAT7 (HBO1) was determined in control progenitor cells by CUT&Tag. 2 mutant (conditional knock out) vs. 2 control haematopoietic stem were assessed for the genomic distribution of histone H3 lysine 14 acetylation (H3K14ac) by CUT&Tag. Control progenitor cells were assessed for the genomic distribution of KAT7.