AUTS2 confers transcriptional activation to PRC1 in the CNS (RNA-Seq)

Naturally occurring variations of Polycomb Repressive Complex 1 (PRC1) comprise a core assembly of Polycomb group proteins and additional factors that include, surprisingly, Autism Susceptibility Candidate 2 (AUTS2). While AUTS2 is often disrupted in patients with neuronal disorders, the underlying mechanism is unclear. We investigated the role of AUTS2 as part of a previously identified PRC1 complex (PRC1-AUTS2), and in the context of neurodevelopment. In contrast to the canonical role of PRC1 in gene repression, PRC1-AUTS2 activates transcription. Biochemical studies demonstrate that the CK2 component of PRC1-AUTS2 thwarts PRC1 repressive activity and AUTS2-mediated recruitment of P300 leads to gene activation. ChIP-seq of AUTS2 shows that it regulates neuronal gene expression through promoter association. Conditional CNS targeting of Auts2 in a mouse model leads to various developmental defects. These findings reveal a natural means of subverting PRC1 activity, linking key epigenetic modulators with neuronal functions and diseases. Overall design: mRNA profiles of P1 brain from wild type mice were generated by deep sequencing