Scacchetti, A., Brueckner, L., Jain, D., Schauer, T., Zhang, X., Schnorrer, F., van Steensel, B., Straub, T., Becker, P.B. (2018). CHRAC/ACF contribute to the repressive ground state of chromatin.  Life Sci Alliance 1(1): e201800024.

FBrf0240677

Research paper

The chromatin remodeling complexes chromatin accessibility complex and ATP-utilizing chromatin assembly and remodeling factor (ACF) combine the ATPase ISWI with the signature subunit ACF1. These enzymes catalyze well-studied nucleosome sliding reactions in vitro, but how their actions affect physiological gene expression remains unclear. Here, we explored the influence of Drosophila melanogaster chromatin accessibility complex/ACF on transcription by using complementary gain- and loss-of-function approaches. Targeting ACF1 to multiple reporter genes inserted at many different genomic locations revealed a context-dependent inactivation of poorly transcribed reporters in repressive chromatin. Accordingly, single-embryo transcriptome analysis of an Acf knock-out allele showed that only lowly expressed genes are derepressed in the absence of ACF1. Finally, the nucleosome arrays in Acf-deficient chromatin show loss of physiological regularity, particularly in transcriptionally inactive domains. Taken together, our results highlight that ACF1-containing remodeling factors contribute to the establishment of an inactive ground state of the genome through chromatin organization.

PMC6238394 (PMC) (EuropePMC)