GSE175952
An NPAS4:NuA4 complex couples synaptic activity to DNA repair [CUT&RUN]
Neuronal activity is critical for adaptive circuit remodeling but poses an inherent risk to the stability of the genome across the long lifespan of post-mitotic neurons. Whether neurons have acquired specialized genome protection mechanisms that enable them to withstand decades of potentially damaging stimuli during periods of heightened activity is not known. Here we identify the first example of a neuronal-specific DNA repair mechanism via a new form of the NuA4/TIP60 chromatin modifier that assembles in activated neurons around the inducible, neuronal-specific transcription factor NPAS4. We purify this complex directly from the brain and demonstrate its function in eliciting activity-dependent changes to neuronal transcriptomes and neuronal circuitry. NPAS4:NuA4 binds at fragile regulatory regions that undergo neuronal activity-induced DNA double-strand breaks and recruits additional DNA repair machinery to stimulate the repair of these sites. Gene regulatory elements bound by the NPAS4:NuA4 complex are partially protected from age-dependent accumulation of somatic mutations. Impaired NPAS4:NuA4 signaling leads to a cascade of cellular defects including dysregulated transcriptional responses to activity, loss of control over neuronal inhibition, and genome instability, culminating in reduced longevity at the organismal level. In addition, mutations in several components of the NuA4 complex are reported to lead to neurodevelopmental disorders and autism. Together, these findings identify a neuronal-specific complex that couples neuronal activity directly to genome preservation and whose disruption may contribute to developmental disorders, neurodegeneration and aging. Overall design: CUT&RUN was performed in the hippocampal tissue isolated from wild-type mice for members of the NPAS4:NuA4 complex.  For most factors, experiments were performed in at least duplicate (exception EP400 Bethyl laboratories). CUT&RUN experiments performed with rabbit IgG serve as controls for non-specific antibody binding.  In the case of NPAS4 CUT&RUN, controls for binding specificity include experiments performed with NPAS4 antibody in Npas4 KO mice and unstimulated tissue, where little to no NPAS4 is expressed.  CUT&RUN in unstimulated tissue, where little to no FOS is expressed, serves as a control for specificity of FOS binding. In addition, CUT&RUN was performed in the hippocampus of Npas4fl/fl mice infected with AAVs expressing wither Cre-mCherry or DelCre-GFP.  DelCre is a nuclease-deficient Cre that cannot excise and so mice are wild-type for the gene of interest.