HMGN1 Modulates Nucleosome Occupancy And DNaseI Hypersensitivity At The CpG Island Promoters Of Embryonic Stem Cells
Chromatin structure plays a key role in gene expression and embryonic differentiation; however the factors that determine the organization of regulatory sites in chromatin are not fully known. Here we show that HMGN1, a nucleosome binding protein ubiquitously expressed in vertebrate cells, preferably binds to CpG islands-containing promoters, and affects the organization of nucleosomes, DNaseI hypersensitivity, and transcriptional profile of mouse embryonic stem cells and neural progenitors. Loss of HMGN1 alters the organization of an unstable nucleosome at the transcription start sites, reduces the number of DNaseI hypersensitive sites genome wide, and decreases the number of Nestin-positive neural progenitors in the SVZ region of mouse brain. Our study provides insights into the mechanisms whereby an architectural nucleosome binding protein affects chromatin structure during embryonic stem cell differentiation.