Chromatin-remodeling protein that binds DNA through histones and regulates gene transcription. May specifically recognize and bind trimethylated 'Lys-27' (H3K27me3) and non-methylated 'Lys-4' of histone H3. Plays a role in the development of the nervous system by activating the expression of genes promoting neuron terminal differentiation. In parallel, it may also positively regulate the trimethylation of histone H3 at 'Lys-27' thereby specifically repressing genes that promote the differentiation into non-neuronal cell lineages. Tumor suppressor, it regulates the expression of genes involved in cell proliferation and differentiation. Downstream activated genes may include CDKN2A that positively regulates the p53/TP53 pathway, which in turn, prevents cell proliferation. In spermatogenesis, it probably regulates histone hyperacetylation and the replacement of histones by transition proteins in chromatin, a crucial step in the condensation of spermatid chromatin and the production of functional spermatozoa. ATP + H2O = ADP + H(+) + phosphate May be part of a nucleosome remodeling and histone deacetylation, NuRD-like, complex composed at least of GATAD2B, HDAC1, HDAC2 and MTA3. Associates with heterochromatin. Specifically expressed by neurons in brain, retina and adrenal gland (at protein level). Also detected in testis. Detected at 15.5 dpc, expression increases after birth and to adulthood. Expression increases in late-stage neuronal progenitor during their terminal differentiation. The PHD domains mediate specific binding to histone H3 unmethylated at 'Lys-4' and may preferentially recruit the protein to transcriptionally inactive genes. The chromo domains mediate specific binding to histone H3 trimethylated at 'Lys-27' (H3K27me3) and may be required in neuron differentiation for proper gene regulation. Methylated at Gln-1392 by N6AMT1. Mutant males are infertile. Mating occurs, but the males are sterile, displaying abnormal spermatogenesis. Disruption of the gene has no effect on the fertility of females. Infertility is due to sperm morphological abnormalities and complete immotility that are observed in all mice. A variable sperm counts, with a complete absence is some individuals is also observed. Spermatogenesis is normal from spermatogonia through meiotic division of spermatocytes. However, at stage IX, step 9, abnormal nuclear morphology of differentiating spermatids appears. It is associated with increased histone retention and decreased histone H4 hyperacetylation, an important step in spermatid chromatid condensation. Finally, spermiation is also affected. Belongs to the SNF2/RAD54 helicase family.