Developmental role for ACF1-containing nucleosome remodellers in chromatin organisation

A Search for Genes Mediating the Growth-Promoting Function of TGFβ in the Drosophila melanogaster Wing Disc

“…Remarkably, Cyp310a1 is the only member of this family that is expressed in the wing disc (Chung et al 2009). Another example is CG1966 (Acf1), which is the fly ortholog of human BAZ1A (Ito et al 1997;Chioda et al 2010), a component of the conserved ISWI chromatin remodeler controlling chromatin assembly and nucleosome remodelling (Erdel et al 2011;Bartholomew 2014). ISWI function has been linked to cell cycle progression and metabolism in genetic screens (Arancio et al 2010), suggesting that the modulation of its expression level is important to sustain imaginal disc proliferation.…”

Basic concepts of epigenetics

“…Other remodeling complexes are involved in gene silencing, such as human ATP-dependent chromatin assembly and remodeling factor, hACF, or its yeast counterpart, ISW2, which arrange nucleosomes by a sliding motion toward formation of organized heterochromatin. 131,132 Human ACF and yeast ISW2 bring nucleosomes toward a state of compaction in close proximity to methylated CpGs, HDACs, TRD-Sin3A/Rpd3 and MeCP2. ACF docks solidly to the nucleosome via PHD fingers in the core histones.…”

Soft skills turned into hard facts: nucleosome remodelling at developmental switches

“…One principle that could favour the recruitment of one complex rather than the other might be a tight developmental expression of the subunits forming CHRAC/ACF or NURF. Indeed, in cleavage nuclei and early gastrulation when the Wg/Wnt signalling pathway is not yet fully activated, ACF1, the defining subunit of CHRAC/ACF, is particularly abundant (Ito et al, 1999;Chioda et al, 2010). ACF1 expression is greatly reduced as development proceeds and NURF becomes the main ISWI complex at later developmental stages when transcription of Wg target genes is activated.…”

“…Indeed, some remodelling factors are more dedicated to the repair of chromatin as opposed to its destruction. For example, ACF1-containing nucleosome remodelling factors seem to be mainly involved in the assembly of fibres with regular nucleosome spacing (Fyodorov et al, 2004;Chioda et al, 2010). Combined with the role of ISWI-containing remodellers that promote the incorporation of linker histone H1 (see above), they assure the integrity of the nucleosome array and its folding into the next level of organization.…”

“…Combined with the role of ISWI-containing remodellers that promote the incorporation of linker histone H1 (see above), they assure the integrity of the nucleosome array and its folding into the next level of organization. Depletion of the diagnostic large subunit of the CHRAC/ACF remodellers, ACF1, leads to sloppy chromatin that is defective in many respects, such as defects in heterochromatin assembly (Fyodorov et al, 2004;Chioda et al, 2010). It seems that the faithful assembly of higher-order chromatin, which is mainly defined by interacting non-histone proteins, relies on a proper 'infrastructure', that is, proper nucleosomal fibre.…”